VfITHSONIAN INSTITUTION 
UNITED STATES NATIONAL MUSEUM 
OBSERVATIONS UPON THE OSTEOLOGY 
OF THE 
NORTH AMERICAN ANSERES 
Dr. R. W. SHUFELDT, U. S. A. 
[From the Proceedings United States National Museum, Vol. XI., pp. 215-251.] 
WASHINGTON: 
1889. Smithsonian Institution 
UNITED STATES NATIONAL MUSEUM 
OBSERVATIONS UPON THE OSTEOLOGY 
OF THE 
NORTH AMERICAN ANSERES 
By Dr. R. W. SHUFELDT, U. S. A. 
[From the Proceedings United States National Museum, Vol. XL, pp. 215-251.] 
WASHINGTON: 
1889. 1888.] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
215 
OBSERVATIONS UPON THE OSTEOLOGY OF THE NORTH AMERI- 
CAN ANSERES. 
BY DR. R. W. SHUFELDT, U. S. ARMY. 
This well-circumscribed order or group agrees with Huxley's Cheno- 
morpha, and contains the Mergansers, Ducks, Geese, and Swans. 
For some time past I have been accumulating the material for a me- 
moir upon the osteology of the entire group of lamellirostral birds of this 
country. I still lack, however, quite a number of important forms, which 
may take more or less time to secure. So that the present memoir must 
not be considered more than an introduction to the subject, though here 
it has the claim of introducing a number of drawings of those forms, 
which can be compared with advantage with other species which I did 
not happen to have in my possession at the time this was written. 
Much of the anatomy of the anserine birds is known to us already, 
but that further elucidation in this direction is very desirable I hardly 
think any one will question. Garrod gave the subject no little attention, 
though he confined himself principally to the condition of the carotids, 
the presence or absence of certain muscles, and the form of the osseous 
portions of the air-passages in a number of the rarer types of Ducks. 
As I have just said, Huxley, in his famous essay upon the Classifica- 
tion of Birds, created a separate group-the Chenomorpluc-to contain, 
with a few related forms, the Anatidw, a division based upon anatom- 
ical characters so far as they were known at the time. 
Cones, in 1884, in the second edition of his Key, availing himself of all 
that was known up to that period which could be successfully utilized 
in classification, awards the anserine birds the order Lamellirostres, di- 
viding it into the suborder Odontoglossce for the single family of the 
Flamingoes, and the suborder Ansercs to hold the Swans, Geese, 
Biver and Sea Ducks, and the Mergansers, these latter each having a 
separate subfamily created for it, to wit, The Cygnince, the Anserine?, 
the Anatince, the Fulignlince, and the Merging, respectively. Collect- 
ively these subfamilies constitute the family Anatidw of this author. 
Some few unimportant changes were made in the American Ornithol- 
ogists' Union Check-List, but this classification remains substantially 
the same. 
Even by their external characters, the Swans, Geese, and Ducks, and 
the more modified Mergansers form a very sharply-defined group of 
birds, and morphology has made quite clear to us the probable rela- 
tion the Flamingoes bear to them. So that it is not very likely that 
further investigations will materially disturb the classification now 
adopted and presented in the Check-List of the American Ornithologists' 216 
OSTEOLOGY OF ANSERES. 
Union. In fact, every advance anatomy has made in that direction 
seems to have been attended by the one result, and that to assure us 
of the soundness of the arrangement in question. 
Instead of this being a signal, however, for the anatomist to cast his 
eyes from this line of work and slacken the activity of his scalpel in 
what he may think profitless employment, it all the more devolves upon 
him to push his researches to a point nothing short of a perfect knowl- 
edge of the structure of these forms. That we have not arrived at any 
such state of perfection I could easily point out. As I have elsewhere 
shown, even so profound an anatomist as Huxley, from lack of material 
and established data, may occasionally fail to properly define an im- 
portant characteristic, as he did in describing the sternum of these very 
Chenomorpha? (P. Z. S., 18G7). Again, it is but recently that Dr. Baur, 
of Yale College, claims to have discovered an additional joint in the last 
digit or the middle finger of the embryo of thd common Duck, a struct- 
ure which is said to be visible at about the time of hatching. 
I have never had reason to change my opinion as to the value, 
the incalculable value, of a complete knowledge of the morphology 
of those living forms best known to us. With such a knowledge of 
the structure of the anserine fowl we are far better prepared to push 
our investigations, with infinitely greater chances of assured results 
into the structure of allied groups than if we were not quite certain of 
each and every detail in the organization of these known forms. 
The Anseres are well represented in the United States, and abundant 
opportunity is afforded to study their structure. 
Further work is much needed in this line upon the air passages of the 
entire group, the generative organs, and other special parts. 
The Mergince constitute the first subfamily under the Anatidce, and 
it has been awarded two genera in our fauna, viz, the genus Merganser 
of Brisson, containing the Mergansers, and the genus Lophodytes of 
Reichenbach, created to contain the Hooded Merganser (L. cucullatus). 
The Mergansers present us with some very interesting points in their 
osteology, and the majority of these can be studied in the skeleton of 
Mergus serrator, a very good specimen of which bird I have now at 
hand. I am indebted to the Smithsonian Institution for the loan of it 
(No. IGG2G of the Smithsonian Institution collection), and will now de- 
scribe its skeleton. 
OBSERVATIONS UPON THE OSTEOLOGY OF MERGUS SERRATOR. 
Of the skull.-We find in this bird that the lamellae of the bill develop 
tooth-like serrations for the entire length of both mandibles. These 
pseudo teeth, however, make no impression whatever upon the osseous 
base of the bill, and in a well-prepared skeleton we would never suspect 
their existence. Upon lateral view of this skull (Fig. 1) we see that the 
superior mandible curves slightly upwards as we proceed toward its 1888.] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
217 
apex; the lower margin is sharp, and above it is convex, except in the 
cranio facial region and somewhat beyond, where it is depressed. 
A nasal is a large, broad bone; its anterior margin is rounded as in 
other holorhinal birds. The nostril is elliptical and placed horizontally, 
and the sutural traces of the bones that surround it entirely obliterated. 
A lacrymal bone is triangular in form, its apex below terminating in a 
spindle-form process, which is curved somewhat outward. Along its 
superior border it anchyloses with the frontal and nasal, the sutural 
trace being quite distinct in the adult skull. Not so, however, in most 
of the Ducks and Geese. 
All anserine birds seem to possess a slender jugal bar; in the case 
of the Bed-breasted Merganser, its distal end turns abruptly upward 
to make its articulation with the quadrate. 
This latter bone has its orbital process widely bifid; its mastoidal 
head is single and roundly convex. 
Fig. 1. Skull of llergus serrator - right lateral view; life size. By the author, from specimen 16626, 
Smithsonian collection. 
The facets at its mandibular foot are two in number, placed obliquely. 
They differ considerably in form and position from the same parts as 
seen in a specimen of a Brant before me. 
The sphenotic process is prominent and gradually curves downward 
along its extent. In most Ducks it points downward and forward. 
We find the hinder moiety of the superior orbital periphery rounded 
off for the lodgment of the nasal gland. The extent to which this is 
carried varies in the different species of anserine fowl. 
About the center of the interorbital septum there occurs a large fenes- 
tra, and the foramina for the exit of the first and second pair of nerves 
are much larger than necessary for this purpose alone. 
The pars plana is a very thin, curved sheet of bone, which supports 
in front a crumpled mass of equally attenuated osseous tissue. This 
latter projects*into the upper space of the rhinal chamber, and no 
doubt plays the part of a turbinated bone. Neither of these outgrowths 
come in contact with the inner aspect of the lachrymal bone of the same 
side. 
The lower margin of the rostrum is straight, rising gently upward 
as it is projected forward, being sharp below along its anterior moiety. 218 
OSTEOLOGY OF ANSERES 
Anteriorly the ethmoid has an elongo cordate outline, the base of the 
figure abutting, against the under side of the cranio-facial region. 
Viewing this skull from beneath we notice a long, narrow cleft in 
rront of the maxillopalatines and bounded on either side by a dentary 
process of the premaxillary. This cleft is deepest behind and gradually 
becomes shallower as it proceeds to the front, where it disappears just 
behind the rounded mandibular apex. 
The maxillopalatines are thin, horizontal plates that are in contact for 
their anterior halves in the median line, but diverge as rounded, dis- 
tinct processes for their posterior moieties. These processes project 
into the wide interpalatine cleft, but do not come in contact either with 
the palatine bones nor with the vomer. This latter is a long, thin plate 
of bone that is grasped by the small ascending processes of the pala- 
tines behind to anchylos with them, while above it is finished off with a 
rib-like margin which is produced beyond the plate in front as a long 
spiculiform process, with its apex resting upon the middle of the max- 
illo-palatine median suture. 
Each palatine body is a narrow lamina of bone, the anterior end of it 
dilating somewhat before being inserted between and fused with the 
other elements in front. 
These palatines only meet each other, and that only in a point, be- 
hind their common seizure of the hinder end of the vomer. Nor do they 
come in contact with th<^ under border of the rostrum, as they' are pre- 
vented from doing that by the sessile, though large and elliptical, basi- 
pterygoid facets found upon the latter. 
Their heads are separated behind by quite an interval, and each one 
makes a peculiar combination joint with the corresponding head of the 
pterygoid, which develops the reverse articulation for it. 
Immediately posterior to this & pterygoid supports also a sessile ellip- 
tical facet of precisely the same character as the one referred to above 
as occurring on the rostrum, the two coming in contact to form a per- 
fect sliding joint, with smooth and plane surfaces opposed to each other. 
Fig. 2. Skull of JIergus terrator; viewed from above, mandible removed ; life size. By the author, from 
specimen 1C62G, Smithsonian collection. 
Posterior to this articulation a pterygoid is somewhat compressed 
from above downward, and curves gracefully outward to cover with 
its cup like hinder end the spheroidal facet offered to it on the part of 
the corresponding quadrate. 1888. ] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
219 
The basi temporal region is broad and smooth, and a spine-like pro- 
cess at its apex fails to shut out from view the double orifice leading to 
the Eustachian tubes. 
We find the major portion of the crotaphyte fossa upon the lateral 
aspect of the skull. Still it may be seen also from a posterior view, 
where the two depressions approach each other, but are separated by a 
large dome like, supra-occipital prominence. 
This latter is usually pierced by an irregular foramen on either side, 
which is quite characteristic but not always present in the Ducks and 
Geese. In a specimen of Branta canadensis hutchinsii before me a large 
one occurs only on the left side of the prominence. 
Mergus has a large foramen magnum which faces almost directly back- 
ward. The occipital condyle at its lower margin is of a reniform out- 
line with the notch above. 
In the mandible the symphysis is short, and this bone, when seen from 
a superior aspect, is of an acute V-shape form. 
The anterior two thirds of either ramus is narrow, tapering somewhat 
to the front, with both upper and lower borders rounded. On the outer 
surface a deep, median, and longitudinal groove of hair-like proportion 
is drawn along its entire length. 
The hinder third is much wider, nearly double the width, and, iustead 
of being thick like the fore part of the bone, is a vertical lamelliform 
plate. Its border is sharp above, while below it is rounded, being in 
the same line with the inferior border of the anterior two-thirds. 
The ramal fenestra is nearly or quite closed in by the surrounding 
elements; a long, oblique slit marks its site. A curved projection is de- 
veloped on the outer aspect of this part of the bone; that above appar- 
ently takes the place of part of the coronoid process. 
Each mandibular facet presents two oblique grooves upon an area 
contracted to the minimum extent that would accommodate the man- 
dibular foot of the quadrate that articulates with it. 
Behind, either angle is produced backwards as a recurved and ver- 
tical lamina of boup, to the inner side of which we find the circular 
entrance to a deep conical pocket. 
Mergus serrator has an enormous bilobed tracheal tympanum at the 
pulmonic bifurcation of its windpipe. These interesting structures 
vary much in form and size in the different species of birds that pos- 
sess them, and would well repay a general comparison. 
Of the vertebral column and ribs.-This Merganser has sixty-one ver- 
tebrae in its spinal column ; the first pair of free ribs occurring on the 
sixteenth; then follow five others that have ribs connecting with the 
sternum by costal ribs; seventeen anchylos to form a sacrum for the 
pelvic bones; and, finally, we find seven free caudal vertebrae besides a 
pygostyle. All these segments are freely movable upon one another, 
except those in the sacrum. In Mergus the odontoid process of the 220 
OSTEOLOGY OF ANSERES. 
second vertebra does not perforate the cup of the atlas from behind, 
but both these segments, in common with many Ducks, present the in- 
teresting condition of having the lateral vertebral canals at the outer 
sides of their centra, for the protection of the vessels that passthrough 
them. This canal is a very prominent feature through all of these cer- 
vical vertebrae through the twelfth; in the first five or six it has a fe- 
nestra in its lateral wall on either side. With the exception of the last 
few vertebrae in which it occurs, it extends nearly the full length of the 
centra, while its inferior wall includes the greater part of the parial 
parapophyses, and these latter being rather widely separated, we have 
as a result a broad area at the under side of all of these vertebrae where 
this construction obtains. 
The hyapophysial canal is found in the sixth to the twelfth, inclusive, 
but in none of these does it close in entirely, though the processes ap- 
proach each other very near in the last-mentioned vertebra. 
Axis vertebra has a prominent hyapophysis, but it is missing in the 
third vertebra, and this process does not make its appearance again 
until we find it as a conspicuous median plate in the thirteenth. In 
the fourteenth it is smaller, and although still in the vertical plane, evi- 
dently moved slightly to the left of the median line. This last condi- 
tion is more pronounced in the fifteenth, while in the sixteenth, where 
it still possesses considerable size, it is carried so far to the left as to 
be nearly in the same plane with the side of the vertebra, though it 
still remains vertical. Sixteenth vertebra also has lateral hyapophysial 
cornua, which makes this peculiar shifting of its mid-process all the more 
striking. I am unable to say at present whether this is a constant con- 
dition of affairs or not. The dorsal series also have hyapophysial proc- 
esses ; these are at first short, with spreading cornua, to gradually be- 
come longerami lose their terminal bifurcation, and again grow shorter, 
to finally disappear on the first sacral, or dorso lumbar. 
Axis has a thick and heavy neural spine. In the following six or 
seven segments this gradually becomes longer, lower, and thinner, to 
be absent entirely in the tenth cervical vertebra. In the fourteenth it 
re-appears, and irom it, backward, it gradually assumes the broad, ob- 
long plate which is perfected in the dorsal series. The vertebrae of this 
latter region are restricted in their movements upon one another by the 
many interlacing tendinal and metapophysial spicuhe among them. 
In the cervical region the neural canal is cylindrical in form, and 
owing to the fact that neither the pre- or postzygapophysial facets are 
upon spreading limbs, in its anterior division this tube is wonderfully 
well protected, its walls being nearly continuous from one vertebra to 
the next. This condition does not obtain in the latter half of the cer- 
vical region, however, where the prolongation of the aforesaid apophy- 
ses lend to the dorsal aspects of the vertebrae, when viewed from above, 
that familiar capital-letter of-X appearance, with the extremities of the 
lines alternately articulating above and below. 1888.] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
221 
This disappears again in the dorsal series, where they are closely in- 
terlocked with each other, and the neural tube once more becomes con- 
tinuous. For the rest we find that the "heterocoelous" plan of articu- 
lation prevails among these vertebrae thus far described; that the 
centra are much compressed laterally in the dorsal region, where also 
the transverse processes are unusually wide and some of their spiculi- 
forni interlacements more than commonly broad. With the exception 
of the atlas they are all pneumatic. 
The pair of free ribs that are attached to the sixteenth vertebra are 
long and pointed, with free extremities. They do not, however, bear 
epipleural appendages. 
Nothing peculiar marks the ribs of the dorsal series nor the haema- 
pophyses that connect them with the sternum. The epipleural append- 
ages are large and all are closely, though freely, articulated with the 
posterior borders of their ribs. 
The first pair of sacral ribs are like the dorsal ones, except they have 
no epipleural appendages. The last two sacral pair, however, anchylos 
with the pelvis, and their luemapophyses do not reach the sternum. 
Of the sternum (Figs. 3 and 4).-Mergus has an interesting form of 
this bone, and it differs in a number of points from the sterna of its sup- 
posed nearest allies among the Ducks. The body is of an oblong out- 
line and moderately well concaved above. Bight over the anterior 
border in the median line there is a single semi-globular pit, but there 
appears to be no pneumatic foramina of any size at its bottom. 
The costal processes are large, prominent, and quadrate plates. They 
extend behind the first hsemapophysial facet. These latter articulations 
are six in number, and the lateral borders behind them are sharp, curv- 
ing at first outward, before they extend backward, to the xiphoidil 
margin. 
Upon the convex, pectoral aspect of the bone we are to notice the 
principal muscular lines. These extend directly backward, one on either 
side, from the lip of bone that overarches the outer end of the coracoidal 
groove, to pass along the inner side of the vacuities behind, where they 
become very faintly marked. 
A transverse straight line limits the xiphoidal extremity, and en- 
grafted upon this in its middle we find a distinct convex prolongation 
of no great size, its base being rather less than one-third of the border 
upon which it occurs. 
Just over this latter, in the apertures of the postero-external angles 
of the bones, we find on either side a large, oval fenestra. 
A sternum of this shape, differing as it does in this particular from 
the notched style of the bone among most of the Geese and Ducks (for it 
is the same as we find it in Glaucionettaf forms an exception to the 
character laid down by Huxley for his Chenomorphee, which includes the 
subfamily to which Mergus belongs. (Fig. 3.) 222 
OSTEOLOGY OF ANSERES. 
The extensive coracoidal beds of the anterior border are separated 
by a pit in the median line, and not a vestige of such a thing as the 
manubrium is to be seen. 
From the pit just mentioned to the far-projecting carinal angle a 
straight osseous welt is raised, above which the anterior margin is 
convex and sharp. 
Fig. 3. Sternum of Hergus serrator; pectoral aspect; life size. By the author, from specimen 16626, 
Smithsonian collection. 
The keel itself is low and extends clear back to the hinder margin 
of the bone proper; its inferior border is thickened and gently convex 
throughout its extent. 
As a very good example of the appearance of the sternum among 
the Ducks I present a drawing of the pectoral view of the bone chosen 
irom the American Eider (5. dresseri, Fig. 13). In this form the pro- 
foundly two notched hinder portion is well shown, and here, too, we 
observe that the anterior part of the keel does not project as in Mergus, 
though it is not an uncommon thing to find it so even among true Ducks. 1888/ 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
223 
Of the shoulder girdle (Fig. 5).-Most Ducks, and I believe all the 
Mergansers, have a non-pneumatic pectoral arch. It is the case in our 
present subject, and in a number of the former at my hand. 
The furcula typifies the broad U-arch in 
Mergus, where the curve is continuous and 
unchecked by the presence of a hypoclei- 
dium. 
The bone is, as a whole, slightly curved 
backward, so each limb presents a convex- 
ity to the front; these become broader and 
laterally compressed as we pass in the direc- 
tion of their free extremities. 
Either head very gradually tapers off to a 
point, and these produced ends ride over the 
scapuhe when the arch is articulated. 
Projecting from their upper borders we 
find a single distinct and vertical process of 
bone that is quite characteristic. In the 
Eider this is in cartilage, but otherwise the 
fourchette is formed in this Duck very much 
the same as in the Merganser. (Fig. 14.) 
In a coracoid we find the summit of the 
bone much produced above its articulation 
with the scapula, and compressed in the 
same plane with the shaft below it in such 
a manner that when articulated with the 
sternum the front of the bone is directed 
forward and outward. 
The sternal extremity of the bone is very 
much expanded, and it also is found in the 
same plane with the general compression of 
the shaft. 
Behind it is scarred by muscular lines, 
and shows a large luniform facet for the 
groove on the sternum. 
The scapular process of the coracoid is to 
a great extent aborted; its superior margin 
being insufficient to accommodate the entire width of the scapula. 
Nothing of importance distinguishes the glenoid cavity, it being 
formed, as in most birds, in the proportion of one-third on the part of 
the scapula and the remainder by the bone under consideration. 
The scapula is much arched, and nearly of an equal width the entire 
length of its blade, its apex being rounded off. We find the bone con- 
siderably compressed in the vertical direction throughout, and the 
length of the chord measured between its extremities less than the 
length of/he coracoid. 
Fig. 4. Sternum of Mergut ser- 
rator; right lateral view; life size. 
By the author, from specimen 16626, 
Smithsonian collection. 224 
OSTEOLOGY OF ANSERES. 
Of the pelvis and caudal vertebrae.-In order to better illustrate the 
fact that the pelvis in the Mergansers is constructed upon the same 
plan as that bone in other anserine birds, I have contrasted it, in Figs. 
7 and 8, with the pelvis of the American Eider Duck. It will be seen 
ata glance that all the characters present in the latter are also to be 
found in Mergus, simply somewhat modified in concordance with its life 
as a diver. 
Fig. 5. Left scapula and coracoid, with furcula detached, Mergus serrator; life size. By the author, 
from specimen 16626, Smithsonian collection. 
The ribs of the first three vertebrae that anchylos in the sacrum 
have already been described when speaking of these bones in general. 
Next to them we find that the three succeeding vertebrae throw out 
their apophyses to the pelvis and firmly anchylos therewith. After 
them we fall into the deep and oblong pelvic basin possessed by this 
bird, and the next three vertebrae send their processes directly upward. 
They are followed by a series of eight more that gradually approach the 
free caudals in form. The anterior one of these has the strongest lat- 
eral processes, but they are found to abut against the ilia on either side 
at a point anterior to the middle of the ischiac foramen, and not right 
behind the cotyloid cavities as in many other birds. The inner margins 
of the ilia anchylose with the outer ends of these sacro-vertebral apoph- 
yses, from the acetabula, backward, excepting the last one. 
Opposite the cotyloid cavities we find the enlargement to accommo- 
date that part of the spinal cord where the sacral plexus is thrown off; 
the openings for the exit of the latter are double, being placed one 
above the other. 
Viewing this pelvis of Mergus serrator from above, we always find, 
jutting out in front, a tuft of bony spiculae that form a part of the same 
system that strap the dorsal vertebrae together. 
The inner margins of the ilia meet and anchylos with the top of the 1888.J 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
225 
common neural spine of the leading vertebrae, converting the ilio-neural 
grooves into canals. 
Each preacetabular portion of an 
ilium is much shorter than its post- 
acetabular part, and also on a very 
much lower level. In front its bor- 
der is emarginated, transversely 
truncate, and somewhat serrated. 
The surface of the bone is concave, 
and for the most part looks upward 
and outward. 
Behind the acetabulum most of 
the ilium is devoted to the lateral 
aspect of the pelvis. 
Turning to this side of the bone, 
we notice a pro-pubis of considerable 
size in front of the cotyloid ring, 
while the post-pubic element is a 
long slender rod, extending directly 
between the under side of the ob- 
turator foramen and the postero- 
external anole of the ischium, with 
which it articulates. Beyond this, it 
trebles its width and curves rather 
abruptly toward the fellow of the 
opposite side. A very narrow, open 
strait connects the obturator fora- 
men and the obturator space; the 
former being rather smaller than 
usual and the latter very large. 
The lower margin of the ischium 
is conca ve down ward and very sharp, 
while the posterior border of the 
pelvis, formed by both the ischium 
and ilium, is perpendicular to the 
long axis of the bone. It shows one 
or two indentations that are not to 
be found in the same pelvic border 
of the Eider. 
The acetabulum is large, with its 
inner and outer rings nearly of the 
same size; an antitrochanter of mod- 
erate dimensions stands between it 
and the antero-superior margin of 
the large elliptical ischiac foramen. 
Posterior to this latter anerture the ilium rises as a smooth dome 
Fig. 6. Right lateral view of pelvis, caudal 
vertebrae, and sacral ribs of Mergui serrator ; 
life size. By the author, from specimen 16626, 
Smithsonian collection. 226 
OSTEOLOGY OF ANSERES. 
above its own postero lateral plane and the ischium which lies be- 
low it. 
In the present specimen this convexity shows a large fenestra in 
either ilium at its anterior part. No such vacuity exists in the Eider 
nor other Ducks in my possession. In some specimens the bone in the 
same locality is so thin that I expect it occasionally occurs in those birds 
Fig. 7. Pelvis of Hergug serrator; viewed 
from above. (Specimen 16626, Smithsonian 
collection.) 
Fig. 8. Same view of pelvis of Somateria dreg- 
geri. (Specimen 16989, Smithsonian collection.) 
Both figures life size. By the author. 
As already stated there are seven free caudal vertebra and a py- 
gostyle. The neural canal passes through all of the former and a short 
distance into the latter. Above it the neural spines are notched in 
front, and have an elevated, stumpy process behind. 1888. ] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
227 
Tbe ends of tbe shortened diapophyses of the first free caudal are 
usually overlapped by the ilia, but in the next segment these processes 
are much longer, to be longer still in tbe third and fourth vertebra*. 
In the next two they again become shorter, to be entirely abortive in 
the ultimate one. In all they are broad and depressed. 
Chevron bones are freely articulated between the centra of the last 
three or four vertebrae of the tail; they are bifid in front and grow 
gradually smaller as we proceed in that direction. 
The pygostyle is here of considerable size, being an irregular quadri- 
lateral figure, with its lower margin thickened, and all the others thin 
amt cultrate. 
Of the appendicular skeleton; pectoral limb.-When the skeleton of 
the upper extremity is in a position of rest alongside the body, we find 
that the humerus is somewhat longer than the bones of the antibra- 
chium, and the pinion also projects beyond them behind to the full ex- 
tent of the last phalanx of index digit. 
The humerus is characterized by a broad, proximal extremity, showing 
an enormously deep pneumatic fossa, and a distinct trench between the 
ulnar crest and articular head, running beneath the latter. Its cylin- 
drical shaft shows the usual sigmoid curves from radial and anconal 
views. Nothing unusual marks its distal extremity, where we find the 
trochlear tubercles for radius and ulna. 
These latter bones are non pneumatic, in common with the remainder 
of the skeleton of this limb. The shaft of the radius is straight, whereas 
it is curved in the ulna, the concavity occurring on the side toward the 
interosseous space. 
The cylindrical shaft of this latter bone is faintly marked by a double 
row of papillae for the secondaries. 
In the carpus we find the two usual segments of forms common to 
the majority of the class. 
In the pinion the bones are all remarkably well developed. Carpo- 
metacarpus has its main shaft straight and of a caliber intermediate 
between those of the antibrachium, or larger than the shaft of radius 
and smaller than the shaft of ulna. First metacarpal is short and aneby- 
losed in the usual manner to shaft of index. The long trihedral pollex 
phalanx bears a distal joint, which is also the case with the second pha- 
lanx of index digit. 
All the bones of the pelvic extremity are non-pneumatic, though the 
principal long ones have sizable medullary cavities. 
The femur has a very large head, which rises somewhat above the 
broad articular summit of the shaft, notwithstanding its crown is con- 
siderably excavated for the ligamentum teres. The axis of its neck 
makes an angle with the axis of the shaft. 
Trochanter major is suppressed above, while on the anterior aspect 
its thin edge partly surrounds a sort of fossa, where in other birds the 
pneumatic orifices occur. Its shaft is rather compressed from side to 228 
OSTEOLOGY OF ANSERES. 
side and bent very slightly in the anterior direction. About its middle, 
on the posterior aspect, there is a prominent muscular tuberosity, and 
other lines or scars for muscular insertion 
are evident. Of the condyles the outer one 
is the lower, and it is profoundly cleft for 
the fibular head. 
The popliteal depression is represented 
by a characteristic conical pocket just above 
the internal condyle on the posterior aspect. 
The rotular channel in front is also deyp, 
but does not extend up the shaft a great 
distance. 
From this same specimen I have illus- 
trated the patella of this Merganser else- 
where (Proc. U. S. Nat. Mus., Vol. vn). It 
is seen to consist of two segments, with an 
oblique groove in the cartilage connecting 
them. Through this the tendon of the 
ambiens muscle passes. 
Tibiotarsus has a straight shaft that, un- 
like the femur above it, is somewhat com- 
pressed from before backward. At its proxi- 
mal extremity we find a cnemial process 
reared above its articular surface for the 
femur. Prominent cnemial ridges occupy 
the anterior aspect of this, as usual. Of 
these the procnemial ridge is the higher 
and extends the lower on the inner side of the shaft. 
The (listal end of tibio-tarsus presents nothing peculiar. The groove 
anteriorly is deep, and the osseous bridge that spans it is thrown directly 
across. The external condyle is the broader in front, and its outer 
aspect is in the same plane with the side of the shaft, while the corre- 
sponding surface of the inner condyle lies beyond the plane of the shaft, 
for its own side. 
Behind, these condyles still continue to be parallel to each other, but 
separated by an intercondyloid concavity that from its shallowness is 
scarcely worthy of the name, while the condyles themselves really merge 
into a broad, articular surface in this locality. 
The fibula, when articulated, is found to rise above the summit of the 
tibia and project beyond it posteriorly. Its head is compressed from 
side to side, which gives it a very short, transverse diameter, while its 
antero posterior one is fully three times as long. The articulation with 
the fibular ridge on the side of the tibio-tarsal shaft exceeds in length 
that portion of the bone that projects above it, and equals in length 
the slender portion that is found below. The connection between the 
bones along this ridge is of a ligamentous nature, and the distal fibular 
Fig. 9. Left tarsometatarsus; an- 
terior view, Mergus serrator. (Speci- 
men 16626, Smithsonian collection.) 
Fig. 10. Same boneseen from below. 
Fig. 11. Corresponding bone from 
Somateria dresseri. (Specimen 16989, 
Smithsonian collection.) 
Fig. 12. Same bone as Fig. Il, seen 
from below. All these figures life 
size. Drawn by the author from the 
specimens. 1888.] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
229 
end seems to be attached pretty much in the same way to the side of 
the tibial shaft. This latter articulation occurs at a point about the 
uuction of middle and lower thirds of the shaft of the larger leg bone. 
Fig. 13. Sternum of Somateria dresseri; pectoral aspect. (Specimen 16989, Smithsonian collection.) 
By the author. Life size. • 
With the exception of its proximal fourth, the tarso-metatarsus is con- 
siderably compressed from side to side, much in the same way as we 
find it in the Urinatoridce. and to the same 
end. 
In order to show that this is simply an- 
other example in the skeleton of this Mer- 
ganser of a physiological adaptation of 
structure to meet a certain requirement 
demanded on the part of its habits, I have, 
in Figs. 9 to 12, contrasted this bone, in 
two views, with the same bone taken from 
a specimen of the American Eider Duck, 
a bird far less noted as an habitual diver. 
It will be seen at a glance that fundament- 
ally these two bones are essentially upon 
the same plan of structure, or, in other 
words, both are of an anserine type. The 
hypotarsus of this bone in Mergus consists 
of four vertical ridges-an inner large and longest one and three others 
Fig. 14. The furcula of Somateria dres- 
seri; life size. (Specimen 16989, Smith- 
sonian collection.) By the author. 230 
OSTEOLOGY OF ANSERES. 
of equal length. They form the grooves for the usual flexor tendons 
passing to the toes. 
Notwithstanding their lateral compression, the trochleae of the distal 
end are very large, their median grooves distinct, and carried all the 
way around. The inner trochlea is elevated upon the shaft, and only 
descends as far as the base of the middle one. It is also turned slightly 
inward, and at the same time projects the farthest behind. The usual 
foraminal perforation is seen in the furrow between the middle and 
outer trochleae, just above the cleft that divides them. 
We find the accessory metatarsal of a moderate size and elevated far 
above the inner trochlear projection-not articulating with the shaft of 
the tarso-metatarsus, as in many birds, but attached to a ligamentous 
structure stretching between the lower part of the hypotarsus and the 
trochlea above mentioned. 
The hind toe which it supports is fully developed, with basal joint 
and claw, though it is proportionately much smaller in comparison with 
the three anterior toes with their large joints. 
These latter need no special description, they are articulated and fash- 
ioned as in the anserine fowl generally, as well as being conformable 
with the most usual arrangement in regard to number of joints allotted 
to the several toes. We may fancy that a certain amount of lateral 
compression is present in the phalanges of these podal digits, but if it 
is so, it is very slight, being little more in degree than is enjoyed by 
like skeletal parts in the feet of the Anatince. To present the characters 
of the skeleton of the Anatinoe more in detail, I have chosen for the 
purpose a specimen of the common Spoon-bill Duck (Spatula clypcata) 
and will now rapidly review its osteology. 
OSTEOLOGY OF SPATULA CLYPEATA. 
So far as its skeleton goes this bird is very closely allied to the Teals, 
a fact that perhaps might not be suspected on first sight from external 
appearances alone. Beyond its increase in size, the chief point in de- 
parture from this genus is seen in the enormous development of the 
premaxilla and a corresponding enlargement of the mandibles (Figs. 15 
to 18, Pmx,). 
In the dried and properly prepared skull of Spatula, this premaxilla 
is an elegant, symmetrically formed, yet delicate scroll of bone, and, so 
far as I am aware, unequaled by any similar structure among verte- 
brates. At the middle part of the anterior arc there occurs a thicken- 
ing, which in life supports the "nail" of the integumental sheath. 
Both this and the region on either side is quite thickly studded with 
foramina. 
The external narial apertures are placed well back, as may be 
seen in Figs. 15 and 16, they being of a subelliptical outline. Com- 
paratively speaking, these openings are considerably larger in the 
Swans and Geese, while in such a form as Glaucionetta islandica they 1888.] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
231 
relatively occupy a mid site on the mandibular side, the nasal being a 
broader bone. I have figured a side view of the skull of this latter 
Duck in Cones's "Key," second edition, where this feature may be seen. 
Spatula and the Teals always have the extremity of the nasal median 
processes of the premaxillary remain distinct to a large extent in the 
cranio facial region throughout life (Fig. 16). This is also well shown in 
the Mallard, less so in Olor, and barely observable in Hatchin's Goose. 
Fig. 15. Kight lateral view of the skull of Spatula clypeata. cf; life size. From a specimen in the 
author's cabinet, and used throughout this article where this form is figured. I, lachrymal; 1'mx, 
premaxillary; q, quadrate; pt, pterygoid; pl, palatine; Mxp, maxillopalatine. 
Mobility of the cranio facial hinge, however, does not seem to depend 
upon this condition, for in Glaucionetta, where a considerable amount 
is enjoyed, this individualization of the nasal processes of the premax- 
illa does not obtain to such a marked extent. 
Confining ourselves for the present to the lateral aspect of the skull 
(Fig. 15), we find a notorious anatidine character very pronounced in 
Spatula, and this is theenormous development of the lachrymal (/) and 
the consequent antero extension of the lachrymo-frontal region. 
The descending process of this bone reaches backward toward the 
long sphenotic apophysis, nearly to touch it in Glaucionetta,, in which 
Duck it usually lacks the terminal dilation so prominent in our subject, 
and still more so in the Swans. The interorbital septum rarely shows 
any deficiencies in its bony' plate, the Golden-Eye being the only form 
in which I have met such a condition, and in this fowl it is very small. 
In all Anatidoe the osseous pars plana seems to be aborted, simply a 
low, bony ridge indicating where it is developed in other birds. The 
mesethmoid is developed, however, as a strong median abutment ex- 
tending far forward beneath the cranio-frontal region. 
A vacuity usually occurs throughout the group, high up on the pos- 
terior orbital wall, though the foramen for the exit of the olfactory 
nerve is not notably large, and the one for the optic is distinct from the 
outlying smaller nerve apertures about it. 
Most Ducks and the Brant have the track for the passage of the 
olfactory to the rhinal chamber an open groove, while in Olor it may 
be practically overarched by' bone. 
As already intimated in a former paragraph, Spatula, in common 
with others of the suborder, had a greatly' lengthened sphenotic or 232 
OSTEOLOGY OF ANSERES. 
post-frontal process, while the squamosal projection would hardly 
attract attention in any of them. 
The infraorbital bar is long, nearly straight, narrow, and much com- 
pressed from side to side. On its upper edge beneath the lacrymal a 
little papilli form elevation is usually seen. Its 
quadrate extremity is slightly tilted upward be- 
fore it sinks into the pit in that bone. This up- 
ward deflection is best observed in the Swans, 
not being well marked in our Broad-bill. The 
maxillary (Jfa#) extremity of the bar is in all 
firmly wedged in between the palatine and the 
dentary process of the premaxilla, being com- 
pletely fused with these bones in the adult. 
Anatidce as a rule, and Spatula form no excep- 
tion, possess a large and massive quadrate. This 
bone Las in them a broad and subcompressed 
body of a quadrilateral form, to the antero-supe- 
rior angle of which a spine-like orbital process is 
superadded and rather deflected toward the me- 
dian plane. The mandibular foot of this element 
supports two elongated facets, placed side by 
side with their major axes extended in the trans- 
verse direction. The inner of these facets is al- 
ways the smaller. 
At the mastoidal extremity of the quadrate we 
find a globular head, fairly divided in two by a 
shallow groove running from before backward. 
This articular end is well incased by the sur- 
rounding bone. 
The quadrato jugal and pterygoidal articula- 
tions require no special mention, they being 
much as we find them in a number of other 
water fowl. 
Anatidce have the lateral aspect of the cranium 
smooth and evenly convex, while lower down a 
shallow and vertically elongated crotaphyte 
fossa can generally be pretty well made out. I find it least pronounced 
in Hutchin's Goose, while it is quite strong in the Garrot. In all cases 
it is produced downward upon the highly developed temporal wing, 
which forms the back part of the bony ear-conch. This latter is con- 
spicuous in having, in most Ducks, incurling margins to protect it. 
These latter are not so manifest in the Geese, and they are absent en- 
tirely in Qlor. 
In Fig. 1G we have an upper view of the skull of Spatula, and this 
permits us to gain a very good idea of the enormous development of 
the premaxilla (Pmx). 
Fig. 16. Skull of Spatula 
clypeata seen from above; 
mandible removed; life size. 
Letters as before. 1888.] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
233 
The fronto lacrymal region we observe to be unusually elongated, 
and in this form concaved in a longitudinal median direction. This 
latter feature obtains also in the Mallard and the Teals, where it is 
quite as well marked, while, on the other hand, in the Swans, Brant, 
and Geese this fronto-lacrymal region is not so strikingly lengthened, 
being flat in some of the latter and mounded up in some Cygninoe. 
The space between the orbital margins on 
this aspect shows considerable width, more 
particularly in such forms as Glaucionetta, 
where it is marked by a longitudinal median 
crease. 
The supraorbital glandular depressions for 
the nasal glands, so prominent in many of the 
Auks and other water fowl, are here in the 
Anatidce rarely well marked. 
In Spatula they consist in a very narrow 
trimming off of the edge of the orbital periph- 
eries, barely perceptible in the Mallard and 
Anas carolinensis. In Glaucionetta they are 
better developed, but in this Duck they are 
really moved down so as to form one of the 
features of the lateral aspect of the skull 
(Fig. C3, u', Cones's "Key," 2d ed.). They 
are quite well marked in the Ilutchin's Goose. 
Spatula, Anas boschas, and the Teals have a 
strongly incised notch on either side, at the 
anterior arc of the supraorbital rim, which 
seems to define the posterior ending of the 
lachrymal bone. It is absent in the Garrot, 
but again characteristic in Swans and Geese. 
The vault of the cranium behind is, upon 
this aspect, usually smooth and rounded. A 
longitudinal crease may pass it in the middle 
line, and elevations on either side in some 
forms {Spatula, Olor) faintly indicate the divi- 
sions of the encephalon within. 
Turning now to the under view of the skull 
of the Spoon-bill, we are to note the great con- 
cavity of the premaxillary, with its sharply- 
defined parial gutters for vessels and nerves ar 1 their ramifications. 
As is well known, all the Anatidce exhibit the typical desmognathous 
arrangement of the palatal bones. The maxih) palatines unite in the 
middle line to form a large bony mass {Mxp}, in front of which there 
occurs in all the Chenomorphae, that I have been enabled to examine, a 
more or less cleanly cut elliptical opening, the remnants of a much 
greater vacuity of other birds. In the Swans these maxillo palatines are 
17. Under side of the skull 
i Ljjatula clypeata; mandible re- 
^wved; life size. Same specimen 
with Mxp, maxillo-palatine, and 
the other letters as before. 234 
OSTEOLOGY OF ANSERES. 
quite spongy; in Branta canadensis hutchinsii they unite with a firm lamel- 
liform nasal septum that makes a long abutment against the roof of the 
rhinal chamber above. This nasal septum is entirely absent in Spatula, 
and illy developed in Anas carolinensis and the Mallard. 
My drawing of the basal view of this Duck illustrates Coues'u "Key," 
(Fig. 78), where the above points may be compared with advantage. 
In Spatula (and the arrangement, with a few unimportant minor dif- 
ferences, holds good for the group) the palatines {pl) are horizontally 
compressed at their anterior ends, where they form anchylosed schin- 
dylesial articulations with the premaxilla and maxillaries, as already 
described. The body of one of these bones is slenderer along its middle 
length, separated by a wide interval from its fellow, and half the dis- 
tance from the vomer (r). 
Its "ascending process" is short, and is carried along the upper vo- 
merine margin, where it unites with the opposite palatine to form a Ion- 
Fig. 18. Rear view of skull of Spatula clypcata. 
Fig. 19. Rear view of skull of Glaucionetta, 
islandica. Both figures lite size, from the speci- 
mens. Mandibles removed. Letters as before. 
gitudinal, rib-like re-enforcement along the upper edge of that bone. 
It is only in this situation that the anserine palatines meet each other. 
The joint that one of these bones makes with the corresponding ptery- 
goid {pt) is a sort of mortise and-tenon arrangement that very per- 
fectly meets the requirements of the parts involved. 
The palatines barely escape resting against the under side of the 
rostrum of the sphenoid, which passes immediately above them. This 
is true of all the Anatidoe so far as I have seen. 
As to the vomer {v) proper, we find it to be a thin lamella of bone in 
the median line, supported, as pointed out above, by the rib on its 
upper margin developed from the ascending processes of the palatines. 
This portion is carried forward by a thickening of the vomer itself, 
somewhere beyond its middle, as a protuding spine like anterior pro- 
cess. 
This spine usually rests in a groove formed by the union of the max- 
illo-palatines behind, though in the skull of a female Mallard before me 
not only this projection, but a good share of the vomerine plate has 
fused with this maxillo-palatine mass in part, to become immovably 
connected with them. 1888 ] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
235 
The lower margin of the vomer is sharp, and the whole plate is gently 
arched in such a manner as to make the upper edge convex along its 
continuity, the reverse obtaining below. 
When speaking of the palatines I neglected to invite attention to the 
notch found on the inner margin of either one of them about opposite 
the anterior termination of the vomerine plate. This notch is converted 
into a foramen in the Mallard, and entirely absent in Hutchin's Goose 
and the Whistling Swan. 
Spatula possesses a pterygoid (pt) of the same general form it assumes 
in any of the Anatidw. Its shaft is short and straight, while its anterior 
end is much enlarged, first, by a descending lamina of bone developed 
upon it and, secondly, by the large sessile, elliptical facet on its oppo- 
site side for articulation with a similar facet on the sphenoidal rostrum. 
Anterior to this facet the pterygoid develops an upturned process of 
spine like dimensions, which, when the bones are in situ, is closely ap- 
plied to the back side of the ascending process of the palatine. Below 
this process the pterygoid is deeply and roundly notched to receive a 
peg-like projection on the palatine, which movably fits into it. 
The projecting and rounded postero external angle of the palatine 
extends below this pterygoidal articulation. 
Generally the lower border of the rostrum is rounded; it is very 
broadly so in Brant, though it becomes quite flat in Glaucionetta ; there 
it may be carried forward as a projecting process. 
The anterior ethmoidal edge is always sharp, sloping forward and 
upward to become a median crest on the under side of that part of the 
bone which abuts against the frontal region for its entire length. 
In Spatula the basitemporal region is quite broad, and marked by a 
median and rounded ridge. This is carried out upon the pointed lip of 
bone that under-laps the double entrance of the Eustachian tubes in 
front. A decided dimple is found in front of the sessile and superiorly 
notched occipital condyle, while the foramen magnum is large, of a 
cordate outline, with its apex directed upward. 
Laterally we find the descending temporal wings, with the usual 
group of foramina to the inner side of each, at the base of quite a well- 
marked little fossa. 
The plane of the foramen magnum makes an angle of about 45° with 
the backwardly produced plane of the basis cranii. 
A posterior aspect of the skull of this Duck (Fig. 18) shows a con- 
spicuous supraoccipital prominence, with a large, vertical, and ellip- 
tical foramen opening into the cranial casket on either side of it. The 
occipital area is well divided off from the crotaphyte fosste by a raised 
ridge which surrounds it. These last-named depressions are separated 
in the median line by quite an extensive interval. 1 believe they never 
meet in any true Duck. 
This description of the cranial base and posterior aspect of the skull 236 
OSTEOLOGY OF ANSERES. 
in the Spoon-bill practically answers for the Mallard and the Teals, 
though, of course, slight differences do exist. 
In Glaucionetta islandica the basis cranii is proportionately flatter; 
the temporal wings less manifest; a separate ridge bounds the fossa 
for the nerve and arterial foramina externally, and the condyle is more 
prominent and its superior median notch very deep. The vault of the 
cranium is very lofty in this Duck (Fig. 19), and the ridge bounding 
the occipital area almost crest-like. 
Speaking of the unusual height of the cranial vault in the Garrot, we 
find this bird very peculiarly constructed in this particular, for not only 
is the brain case of a size above the average for the group, but a curious 
and not inconsiderable diploic cavity overlies the whole top of the skull, 
extending as far forward as the mesethmoid. Here it is interrupted by 
a pair on either side, one in front of the other, of deep and sharply de- 
fined chambers, with their apertures facing directly downward. This 
condition is not so pronounced in a young female Glaucionetta^ a speci- 
men of which I have before me. 
Branta has a very large brain-case, and upon the under side of the 
skull of a specimen of B. canadensis hutchinsii we note that a quadrate 
has an area of no mean size, and nearly horizontal, extending to the 
rear of its mandibular facets. In this Goose, too, we find a very broad 
and flat basi temporal area, with the shield to the entrance of the Eu- 
stachian tubes nearly aborted. These latter appertures are wide apart 
at the situation usually protected by it. The temporal wings are feebly 
developed in comparison with the Cygnince, and the occipital condyle is 
almost pedunculated. The group of foramina to its inner side of either 
temporal wing is situate at the base of a well-defined fossa specially 
designed to receive them. 
Finally, we observe that the form of the foramen magnum is more 
elliptical in outline rather than cordate, as we found it in the Ducks. 
Above it the supraoccipital prominence is very conspicuous, while the 
foramina on either side of it may or may not exist. 
In the skull taken from a magnificent male specimen of Olor colum- 
bianus* I find the basi temporal triangle comparatively very small, with 
the dimple anterior to the condyle deep and having parial ones placed 
side by side in front of it. The descending temporal wings are enor- 
mously developed, each one overshadowing a considerable excavation 
to its inner side. 
The condyle is relatively smaller than it is in the Geese, and its supe- 
rior notch not so well marked, while the foramen magnum is quite cir- 
cular in outline. Elliptical vacuities may or may not exist at the sides 
* I am greatly indebted to the generosity of Mr. G. Frean Morcom, of Chicago, for 
this present. The bird was forwarded to me by Mr. Morcom from Chicago to Fort 
Wingate, N. Mex., by express. It arrived in excellent condition in the flesh, and the 
fine skeleton it afforded me has been of the greatest service in the present connection. 
When this memoir is published it is my intention to present the specimen to the 
Smithsonian Institution at Washington as a type.-R. W. S. 1888. ] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
237 
of the fairly well-pronounced supraoccipital elevation. The plane of 
the occipital area is nearly or quite perpendicular to the plane of the 
basis cranii. 
Anatidce have their skulls more or less perfectly permeated by air, 
and when properly prepared are really structures of great beauty, as is 
the glistening white skull of the Swan before me, which is so exceed- 
ingly light for its size and withal so graceful in outline. 
Few and unimportant are the differences that are found to exist be- 
tween any two mandibles of representative Anatidee, the general type of 
the structure being quite a uniform pattern, as it prevails throughout 
the entire group. Perhaps Spatula offers us as great a departure from 
the common form of the anatidine mandible as any American Duck we 
have, and even here we find, on side view, that it possesses all the essen- 
tial characters, of the bone as found in the group. Seen upon this latter 
aspect we have presented us for examination the lamelliform and ver- 
tical angular processes. These are greatly produced directly backward, 
to be abruptly recurved upward at their extremities. 
This is the style also in Olor, but in Hutchin's Goose 
they are saber shaped and gradually recurve upward. 
Beyond this process the articular facet projects from 
the ramal side, and at a varying distance (for the 
species) in front of this we find a constant process for 
muscular attachment. This last is situate at about 
the middle of the deepest and most plate-like portion 
of the ramus, and in a Swan is ridge-like, being con- 
nected with the coronoid process on the edge of the 
bone immediately above it. 
In front of this the ramal vacuity-a narrow slit- 
is usually completely closed by the splenial element. 
The bone now becomes shallower in the vertical di- 
rection, its superior and inferior borders rounded, 
while a well-defined gutter for the passage of nerves 
and vessels marks its entire length. 
As a rule, among the Anatidce the symphysis is 
rather deep, rounded beneath, and correspondingly 
concave above, the under side being thickly studded 
with vascular foramina. Spatula has a somewhat dif- 
ferent anterior ending from this, as is shown in Fig. 20. 
In the middle line in front a sort of "nail" is devel- 
oped like the one found on the superior mandible, 
though not so strong. The superior ramal margins 
are continued round this projection, forming its edge, 
while the spoon-like dilatation is insured by the outer 
ramal sides shelving away from this upper border, so 
as to face upward and outward rather than directly 
outward, as they do posteriorly. 
Fig. 20. Mandible of 
Spatula clypeata; seen 
from above; adult cf; 
life size, from the speci- 
men. 238 
OSTEOLOGY OF ANSERES. 
The form most common for the mandible to have, as viewed from 
above, is well exemplified in Glaucionetta, as shown in Fig. 21, which 
presents this aspect of the bone in the Garrot. 
The articular projections lie nearly in the horizontal plane, and each 
one supports the two concavities for the mandibular foot of the quad- 
rate. A rather slender intwined process directed upward and toward 
the medial plane projects from the inner one. This may present a small 
pneumatic foramen at its extremity. Beneath either of these articular 
portions of the mandible, and to the inner side of the angular process, 
we discover a deep conical fossa, with its apex to the front. 
It is intended for muscular insertion, and is pre- 
sent,! believe, throughout the group. 
The mandible is very imperfectly pneumatic, 
particularly in the Brant, where the bone some- 
times, if not always, entirely lacks this condition. 
For the general form assumed by the hyoidean 
apparatus in these birds the reader is referred to 
my figure of these parts as they occur in Branta 
canadensis, in Cones's "Key," second edition, on 
page 107 (Fig. 72). 
Here we find an elongated elliptical piece in 
front, of some width, which represents the glos- 
sohyal and absorbed ceratohyals. It develops a 
median facet anteriorly for articulation, with a car- 
tilaginous rod, which passes into the soft part of 
the tongue proper. 
This glossohyal is longitudinally concaved beneath 
and correspondingly convex above; it articulates 
with the fused basi-branchials, the first one of 
which is by far the stouter element, the second 
almost spiculiform in its dimensions, and produced 
by a cartilaginous tip behind. 
The thyrohyal elements consist each of the two 
usual parts, and these greater cornua curl up grace- 
fully behind the skull, after the fashion of the class 
generally. 
Without entering upon details, I find after careful comparison of a 
sufficient number of skulls, that of the Teals, the Blue-winged species 
(A. discors), more nearly approaches Spatula than any of that genus, 
while, on the other hand, a very close resemblance is seen to exist be- 
tween the skull of Spatula and that of the Mallard, the most evident 
points of difference in these last being the shape of the premaxilla and 
the more robust type of skull possessed by the Mallard. V ith but very 
few exceptions, I believe I have shot every species of Duck in this 
country, yet, at the present writing, 1 regret to say that I have not at 
hand the skulls of the genera Bajila, Anas strepera, nor Anas penelope, 
Fig. 21. Mandible of 
Glaucionetta iglandica; 
seen from above, adult 
cf ; life size ; from nature. 1888.] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
239 
and it will be very interesting to compare these forms on some future 
occasion with those described in the foregoing paragraphs. 
It is a well-known fact that the number of vertebrae in the spinal 
column of the Anat id a; is by no means constant. Even genera sup- 
posed to be quite nearly related may differ in this particular, so that 
careful records in this direction are very much needed, and when a 
sufficient number have been taken to insure absolute accuracy such 
data will be of service. 
In the subjoined table I have but little to offer, but it is the result of 
a careful count in each case, and will go to show some of the differences 
referred to and the method of comparison. 
Species. 
Number of 
vertebra.' in 
cervical re- 
gion without 
free ribs. 
Vertebra; that 
bear free 
ribs not reaching 
sternum. 
Dorsal 
vertebrae (in- 
clusive). 
Vertebrae 
consolidated 
with pelvis 
(inclusive). 
Free caudal 
vertebrae (to 
which pygo- 
style is to be 
added). 
Olor columbianus ... ... 
22 
23d 
24th to 28th 
2Qth to 45th 
46th to 52d. 
Spatula clypeata 
16th 
17th to 21st 
22d to 37th 
15 
16th 
17th to 21st 
22d to 37th 
38ih to 43d. 
Glaucionetta idandica 
15 
16th and 17th ... 
18lh to 2lst 
22d to 37th 
3oth to 43d. 
Now, in the case of Spatula and Glaucionetta, in the specimens before 
me, the thirty-eighth vertebrae, though free and really a caudal, lies 
within the grasp of the hinder ends of the iliac bones, whereas in the 
Teals this segment is found one vertebra's length behind them or entirely 
without their grasp. It will be seen, however, that this does not affect 
the total count,it remaining forty four for the first-named genus and but 
forty-three for the Garrot. I mention this because specimens may yet 
be found where this thirty eighth vertebra has united with the pelvis, 
as from the position it occupies it is perfectly possible for it to do in 
the genera mentioned. 
The general characters of these segments as they are exhibited by 
most Ducks are very well shown in Spatula. 
The atlas has its cup perforated by the odontoid process of the atlas 
vertebra, and is characteristics in having the lateral canals-a feature, 
so far as I am informed at present, that is common to the Anseres. 
An open carotid canal is provided for by the sixth to the t welfth ver- 
tebrm, after which a strong median hypapophysis takes its place, and 
this becomes tricornuted in the sixteenth segment and first dorsal, while 
in the eighteenth and nineteenth it is a long median plate. 
The fifth and sixth cervical usually has the best-marked neural spine, 
which is there a long, though not high, median crest. The lateral ca- 
nals in the first half of the cervical region are long and tubular, while 
the parapophyses are co ossified for nearly their entire lengths with 
their sides. Anatidcv possess the heterocoelous " type of articulation 
among the centra of the spinal column. A strong hypapophysis is found 
on the second and third cervical vertebrae, to be much reduced in the 240 
OSTEOLOGY OF ANSERES. 
succeeding one, while the following segments in the skeleton of the 
neck are notably broad and rather long. In this region one thing is 
sure to attract our attention, and this is the brevity of the pre- and 
postzygapophyses, an arrangement which has the effect of very ma- 
terially reducing the size of the intervertebral spaces or apertures. 
In the dorsal region the vertebrae are not only locked together by 
their close-fitting neural spines, but a very extensive system of meta- 
pophysial and other bony spiculae render the strapping still more effi- 
cient. The transverse processes are very wide, too, so that, notwith- 
standing the fact that these segments are all free, the mobility enjoyed 
by this division of the column is very much compromised. Pneuma- 
ticity is but very imperfectly extended to the vertebrae of the column, 
especially in the cervical region ; while this is likewise true of the 
Swans, this condition in them is very much more complete, and their 
dorsal vertebrae are wonderfully well provided for in this particular. 
The ribs seem always to be non-pneumatic, with large anchylosed 
unciform processes, being wide and flat in the body above the points 
where they are attached. Glaucionetta is notorious for both of these 
characters. 
Spatula has on one side seven ribs that connect with the sternum by 
costal ribs; one pair behind these, where the haemapophysis fails to 
reach that bone, and, finally, a small floating hmmapophysis clinging to 
the posterior margin of the latter. The last two pairs of vertebral ribs 
come from the sacrum and are without unciform processes. 
This arrangement of the ribs prevails also in Anas cyanoptera, while 
in Glaucionetta the series leads off with two pairs of free ribs, one on 
the sixteenth and one on the seventeenth vertebra, the following six 
connecting with the sternum, and three pairs coming from the consol- 
idated sacral vertebra?, making in all nine pairs of ribs to each side, the 
last three not bearing unciform processes. 
In Olor columbianus the arrangement is again entirely different. Here 
we find the series leading off with one pair of free ribs (on the twenty- 
third vertebra), followed by nine pairs that connect with the sternum 
by costal ribs and completed by a purely floating pair that neither joins 
with the pelvis above nor the sternum below. This gives the Swan 
eleven pairs of ribs. Of these the first, and the last four are without 
unciform appendages. In those ribs where they do occur they are 
anchylosed to them and are not notably large. The last four pairs of 
ribs come from beneath the ilia in this Swan and curve far backward, 
reminding us of a condition that is still more pronounced in the Loons- 
Nor is this the only feature in Olor wherein it resembles that family, as 
we will see further on. 
This Swan has a low median hypapophysis on each dorsal vertebra, 
and the neural crests of these segments are comparatively low, being 
laced together by long spiculae, as we described them for the Ducks. 
The skeleton of the tail is much as it is in Spatula and Teals, in 1888.] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
241 
which genera the diapophyses are wide and spreading, while beneath, 
the ventral apophyses are anchylosed to the centra upon which they 
occur and hook forward over the preceding vertebral body. The pygo- 
style in these and most forms of the group is somewhat elongated, of an 
irregular quadrilateral outline, with thickened posterior border. 
Glaucionetta has very wide and spreading transverse processes to its 
caudal vertebne, and the chevron bones upon the last two are free and 
rest mainly upon the intervertebral cartilage, as a greater series of them 
do in the Swans. 
Turning our attention now to the consideration of the pelvis, we find 
this compound bone in Spatula presenting us upon its dorsal aspect the 
following points for our examination: The ilio-neural canals are com- 
pletely closed in by the ilia meeting and anchylosing. with the crista of 
the leading sacral vertebrm. This is the 
case, I believe, throughout the entire or- 
der. On either side of this the pre-ace- 
tabular portion of the ilium is longitudi- 
nally concaved, each anterior border being 
emarginated by raised bone and embel- 
lished with a few projecting spiculm. 
The post-acetabular sacral portion of 
the pelvis is in general in the horizontal 
plane, being pierced in an irregular man- 
ner by a few scattered and small inter- 
diapophysial foramina, while a median 
furrow, deepest behind, marks its entire 
length. 
From this part of the pelvis the sides 
slope gently away. The posterior margin 
is more or less unevenly notched; the 
notch indicating on either side, however, 
the point of union between ilium and is- 
chium is constant both as to occurrence 
and location. So far as we have thus de- 
scribed the bone it will answer in general 
terms for the Teals, but in Glaucionetta 
the pre-acetabular area is notably shorter, 
while behind the bone is more spreading, 
the interdiapophysial foramina far more numerous and larger, and, 
finally, the posterior margin is nearly even. Upon the lateral aspect of 
the pelvis in Spatula we find rather a large cotyloid ring, surmounted at 
its upper and back part by a modest antitrochanter. The ischiac for- 
amen is extensive and subelliptical in outline. Behind this we some- 
times find, both in this species and in the Teals, a thin tract of bone, 
which thinning may be carried to the point of forming another fora- 
men, or a post-ischiac foramen, which is quite large in some specimens. 
Fig. 22. Dorsal view of the pelvis of 
Spatula clypeata. Size of life. 242 
OSTEOLOGY OF ANSERES 
In all the Anat idee that 1 have examined a pro pubis is to be found 
jutting forward from its usual site. This is the case in Spatula. Be- 
hind this a small obturator foramen, nearly closed in, is to be noted, 
while the obturator space is very large and completely surrounded by 
bone behind, through the foot-like precess afforded by the ischium. 
This latter projection articulates with a facet, intended for that purpose, 
on the upper border of the post-pubis. 
The post-pubis is a slender rod as it passes beneath the obturator 
space, but after its articulation with the ischium posteriorly it has its 
width nearly doubled, and in Glaucionetta the hinder ends are slightly 
enlarged. This latter Duck departs from the above description princi- 
pally in such a minor detail as having a relatively much larger ischiac 
foramen and longer obturator space. 
In all of these species we find the pelvic basin upon the ventral aspect 
very capacious, both as to its depth and width. 
As I have already stated elsewhere, the pelvis in Olor has a very dif- 
ferent form from that bone as we find it in the Ducks. It assumes a 
shape that at once brings to our mind the mergine pattern, with its 
greater length as compared with its width; the almost entire disappear- 
Fig. 23. Left lateral aspect of pelvis of Spatula clypeata; life size. Same specimen as Fig. 22. 
auce of the interdiapophysial foramina, and the broad, paddle shaped 
extremities of the post-pubic elements. This model sees its extreme 
modification in the Vygopodes; and if we remove the intrasternal 
chamber for the accommodation of the tracheal loop, we find in the 
sternum, too, of the Swan a great deal to remind us of that bone in 
Urinator. 
Spatula possesses, in common with most Ducks, a completely non- 
pneumatic shoulder girdle. In it we find abroad, U-shaped furcula, de- 
void of hypocleidium and with its long, pointed, clavicular heads extend- 
ing almost directly backward. On the upper side, where either of these 
latter merge with the limbs, we find a peculiar little peg-like process, 
that is quite characteristic of most Anatida\ The scapula is long ami 
curved, the curve being in the plane of its blade, with the convex bor- 
der mesiad. Its posterior end is simply rounded off, and its head makes 
a firm articulation with the broad, scapular process of the coracoid, 1888. ] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
243 
This latter bone has its shaft much compressed from before, backward, 
while its sternal extremity develops an unusual expansion, the infero- 
external angle of which is truncated. 
Anas discors agrees in its pectoral arch, in the main, with the one 
just described for the Br tad-bill. It has, however, a rudimentary hypo- 
cleidium present. 
This latter feature is entirely absent in Glaucionetta, where the fur- 
cula is very strong and its U very broad. Otherwise the bone is gen- 
erally marked by all the characters it bears in the Ducks. The blade 
of the scapula in Glaucionetta is much arched, and shorter and broader 
than it is in the Teals. The coracoid presents nothing peculiar, having 
much the same form that it has in Spatula, though it agrees with the 
Teals in having a comparatively longer shaft. 
Aside from its greater size, Olor possesses a scapula very like that 
bone in Glaucionetta. The Swan has its coracoid, however, very short and 
thick-set, and does not at once suggest to us its family relations, though 
a moment's study is sufficient to trace the modifications and resem- 
blance. The unique form assumed by the furcula of this stately fowl 
is well known to us. Its clavicular heads are long drawn out to termi- 
nate posteriorly in sharp points. Moreover, the bone is highly pneu- 
matic, the foramina being found well up on the outer aspect of either 
limb, in a longitudinal excavation that there occurs. These clavicular 
limbs gradually approach each other as they descend, and when they 
come close to and opposite the middle points of the anterior and ver- 
tical borders of the tracheal entrance to the sternum they are reflected 
upward, and unite as a (J-arch the median line just beneath the 
manubrium. The anterior aspect of this secondary arch is convex, 
while behind it is much concaved, especially at its highest point, where 
a small circumscribed pit occurs. The object of this modification of the 
fourchette in the Swan is to permit the tracheal loop that enters the 
carina of the sternum a passage way, but the requisition of the entire 
arrangement is one of those problems in anatomy which, I believe, 
still awaits a final solution. 
The sternum affords another instance of skeletal likenesses between 
Fig. 21. Left lateral aspect of sternum of Spatula clypeata; life size. Same specimen as before. 
the genus /Spatula, and the Teals; indeed, this bone in the latter genus 
is to all intents and purposes the perfect miniature of the sternum of 244 
OSTEOLOGY OF ANSERES. 
the former Duck. On its dorsal aspect the bone is much concaved 
throughout and presents a single, median, pneumatic foramen just within 
its anterior border. This aperture, though a smaller one, is also seen 
in the Garrot, but the sternum of that Duck is a non-pneumatic one. 
It will be observed from Fig. 21 that the sternum of the Spoon-bill 
possesses quite a prominent, peg-like manubrium, and that its sharp, 
anterior carinal border slopes to the front, forming an acute angle with 
the convex and ribbed inferior margin of the keel at their point of inter- 
section. 
This keel extends the entire length of the sternal body, and is withal 
rather a deep one. The usual swell that fortifies it in front is uncom- 
monly broad. Above the manubrium, in 
front, the coracoidal grooves unite in the 
median line, and the common bed thus 
formed is carried out laterally, on either 
side, to a point opposite the middle of the 
base of the costal process. These latter 
projections are rather lofty and prominent, 
each being of a broad, quadrilateral outline. 
Either costal border occupies less than 
half of the lateral margin, the remainder 
being somewhat curved and cultrate. 
Regarding this bone from a pectoral as- 
pect (Fig.25), we notice that the form of the 
sternal body is oblong, with a slight out- 
curving of the lateral xiphoidal processes 
behind. These latter form the external 
boundaries to the large subelliptical vacui- 
ties, one on either side of the hinder ex- 
tremity of the bone; but they fail to con- 
vert these apertures into true fenestra), from 
the fact that their inturned tips never reach 
the external angles of the Tnid-xiphoidal 
prolongation, as shown in the figure. This 
latter projection always has its posterior 
margin fortified by a raised and thickened 
edge, which is continuous with the rib of 
the inferior carinal border. 
The principal muscular line seen upon either side of this wall of the 
sternum, extends directly from the middle point of that lip of bone 
which underlaps the outer end of the coracoidal groove, to follow the 
inner edge of the xiphoidal notch to the apex of the postero external 
angle of the mid projection, traveling the entire length of the sternum, 
of course, to do so. 
Now Glaucionetta islandica has a sternum of an entirely different 
form from the bone as 1 have just described it for Spatula and the Teals. 
Fig. 25. Under view of sternum of 
Spatula clypeata; life size. Same bone 
as shown in Fig. 24. 1888.1 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
245 
In the first place, its body is relatively much shorter for its width than 
it is in those Ducks, while in front the manubrial process has entirely 
disappeared. Again, the costal processes are loftier and more conspic- 
uous. The xiphoidal extremity of the bone is very broad and is pierced 
well within its hinder margin, on either side, by an elliptical foramen, 
as shown in Fig. 26, where it will also be observed that the carina does 
not extend the entire length of the sternal body, but stops short at the 
Fig. 26. Pectoral aspect of sternum of Glaucionetta islandica; life size. From a specimen in the col- 
lection of the author. 
middle point of a raised line, that, being produced as it is, is tangent 
to the posterior arcs of the xiphoidal fenestra}. 
The muscular lines take about the same course as they do in Spatula, 
with the exception that their posterior ends are inclined inward rather 
than outward, as in the form mentioned. 
This form of sternum agrees in many particulars with the bone as we 
find it in Mergus, though in the Eider Ducks, as I have elsewhere 
pointed out, the xiphoidal extremity is deeply two notched. 
Such differences certainly are significant, and must be awarded their 
due share of weight in the search for affinities among the several forms 
of this order, and it will be interesting to find with what similar char- 
acters they are associated. 
Another engaging subject in the anatomy of the Anatidw is the study 
of the various forms taken on by the osseous labyrinth at the bifurca- 246 
OSTEOLOGY OF ANSERES. 
tion of the bronchi. This is of a very unique shape in Glaucionetta, 
and I have figured a specimen of it as it occurs in this Duck in Cones's 
"Key," showing the development from behind ^second edition, Fig. 98). 
It is my intention, on some future occasion, to make a thorough com- 
parison of these tracheal caskets as they are found in our American 
Anseres, continuing the labors of Garrod and Yarrell in that direction. 
Anseres always have the extremities powerfully developed, and in 
consequence we find strong skeletal supports for their pectoral and pel- 
vic limbs. The bones that enter into them, however, rarely offer any- 
thing peculiar or make any marked departures from the average type 
of the skeleton of the parts in Aves. 
In Figs. 27 and 31 of Cones's Key I offer drawings of the pectoral 
and pelvic limbs of Glaucionetta islandica, and they give a very good 
idea of these bones as they occur among the Ducks generally. It must 
be noted, however, that in Fig. 27 (of the "Key") another small joint 
must be added at D, in order to perfect the limb. This part of the 
skeleton in Glaucionetta is completely non pneumatic; not the case with 
many other Ducks. 
It must likewise be observed that in Fig. 31 the patella is not shown, 
whereas I believe this fowl possesses one in common with other Ducks. 
Professor Cones lettered these two drawings of mine himself, and by 
an oversight has made in Fig. 31 am. point to one of the trochleae of 
tarso-metatarsus instead of the accessory metatarsal. 
Olor, the Teals, and the Spoon-bill all have a perfectly pneumatic 
humerus, the foramina being found at their usual site. 
In the last named species this bone is considerably longer than the 
non-pneumatic ulna and radius. Its radial crest is rather low and short, 
while the ulnar one curls conspicuously over the pneumatic fossa. Be- 
tween this latter and the humeral head a deep notch, or rather groove, 
is found. 
The shaft is of a glistening whiteness, and composed of a wonderfully 
compact tissue, and shows scarcely any curve along its continuity. 
The distal extremity presents the usual characters, the oblique and ul- 
nar tubercle on the radial side and a broad passage for the tendons on 
the other. 
Along the shaft of the ulna we notice a faintly pronounced row of pa- 
pilhu for the secondary quill-butts, a longitudinal muscular line marking 
the opposite side. This bone is considerably bowed along its proximal 
third, while, on rhe other hand, the radius is nearly straight. The two 
carpal elements which remain free throughout life in Aves generally 
are here present, and of a comparatively large size. Ulnare in most 
Ducks, and less so in the Swan, shows a strongly-defined groove down 
its anconal aspect for the lodgment of the tendon which there passes. 
Carpo-metacarpus presents the usual form, and its main shaft is more 
than two-thirds as long as the radius. There are two phalanges in pol- 
lex digit, as there are three in index, the blade of the proximal joint of 1888. ] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
247 
this latter linger being narrow and solid; the little joint behind it ex- 
tending rather more than half way down its posterior border. 
Among the Swans the general plan of the limb is the same, but the 
humerus, an exquisitely beautiful bone in these birds, is but very slightly 
longer than the ulna. 
The skeleton of the pinion is quite as we find it in the Ducks. 
I have yet to find a true American anserine bird that possesses a 
pneumatic bone in its pelvic limb. All the species before me entirely 
lack this character. 
In Spatula the trochanterian ridge of the femur has a thick, curling 
crest on the antero-superior aspect of the bone, but at the summit it is 
leveled down to the same plane with the articular surface. The head 
is rather large and sessile and the excavation for the round ligament 
shallow. 
We find the distal extremity unusually large; indeed, all the bony 
structures that enter into a Duck's knee-joint are large and massive* 
This is particularly the case with the condylar extremity of the femur 
in Glaucionetta, where these prominences are powerfully produced be- 
hind, and a wide and deep cleft splits the outer one for the fibular head. 
In this form, too, a deep pit is found in the popliteal fossa. 
Returning to the femur of Spatula, we note that its shaft is nearly 
straight, being marked by the usual muscular lines, while the pit just 
spoken of is absent. The rotular channel extends slightly up the shaft 
above the condyles, whereas in Glaucionetta this is not the ease, and in 
this Duck the femoral head is notably large and extensively7 excavated 
on top ; the lower third of its shaft is somewhat bowed to the front and 
a little twisted, recalling to our mind the power of that peculiar arch as 
exhibited in such a marked degree in Urinator. 
The Spoon-bill, and I suppose other Ducks will show the same, has 
an ex-traordinarily formed patella, being flat on top, wedge-shaped in 
front, broad and concave behind, deeply excavated and arched below, 
while across its anterior face it is profoundly slit in the. oblique direction 
for the tendon of the ambiens muscle. 
In the tibio-tarsus we find a large, flake like, and jutting procnemial 
crest, which curls toward the fibular side and ends abruptly high up on 
the shaft. The ectocnemial crest is also turned outward, but is low and 
thick. These prominences arc but slightly elevated above the articular 
summit of the bone, while in Glaucionetta they are carried up in such a 
manner as almost to rival (he Grebe in this particular, having very' 
much the same form. 
The tibio-tarsal shaft in Spatula is straight, smooth, and subcylin- 
drical. It affords at its outer side the usual ridge for the accommoda- 
tion of the fibula. This is very long in the Garrot. 
At the distal extremity we find that the entire end is considerably 
bent toward the inner side, a character it presents in many other Ana- 
tidee. The intercondylar notch is for the most part very wide and sbal- 248 
OSTEOLOGY OF ANSERES. 
low, be.ug deepest anteriorly. Above it, in front, the direction of the 
deeply excavated groove for the extensor tendons is influenced by the 
obliquity of the boue spoken of above. The bony bridge that spans it 
is thrown directly across. 
Nothing of particular interest marks the fibula, it having the form 
we usually find in the class. In this specimen of the Spoon-bill its 
feeble lower end anchyloses with the tibio-tarsal shaft at about half 
way down its length. It is very much longer in Olor, where its method 
of ending is the same. 
Equaling about half the length of the leg bone it articulates with, the 
tarso metatarsus also proves to be a strong, stout segment in the limb 
of this Duck. Its hypotarsus is flat and inconspicuous, being marked 
by three vertical grooves for tendons. The four ridges thus formed 
graduate in size, the innermost one being the longest and most promi- 
nent. The sides of the shaft of this bone are, for the major part, flat, 
a slight excavation being seen at the upper end of the anterior one. 
The trochlem at the distal extremity are very prominent and well in- 
dividualized by the deep clefts that severally divide them. They all 
have median grooves passing around them from before backward. The 
mid-trochlea is much the lowest of the three, as well as the largest, while 
the inner one is placed the highest on the shaft, being at the same time 
turned slightly to the rear. The usual arterial foramen occupies its 
site, as in other birds. 
Agreeing with the group generally, Spatula possesses but a feebly 
developed accessory metatarsal, with a correspondingly weak hallux 
composed of a basal phalanx and claw, the whole being suspended 
rather high on the tarso metatarsal shaft by ligament. This discrep- 
ancy in size of the hind toe is likewise seen in the Swans, where it is 
even still more evident. Second, third, and fourth digits, however, 
having three, four, and five joints, respectively, are quite the reverse 
from this, being composed of bones fully in keeping, so far as their size 
and strength go, with the substantial segments of the limb to which 
they belong. 
Of these joints the basal ones take the lead in point of length, and it 
is only in the outer podal digit of the Duck where we find that its pe- 
nultimate phalanx exceeds the joint that precedes it in this particular 
NOTES ON A SKULL OF BRANTA CANADENSIS HUTCHINS1I. 
The characters of the skull as they are seen among the smaller of our 
American Geese are well exemplified in the subject of these brief com- 
parative notes. 
This specimen of Branta I collected several years ago on the Platte 
Biver, in Wyoming, and prepared it as a skeleton at the time. 
I present four figures, giving the four principal views of this Goose's 
skull of the size of nature. Viewing it from the side, we find a superior 
osseous mandible of the form 1 mentioned in the synopsis of characters, 1888.] 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
249 
but much shorter than in Ducks aud Geese generally. We note here 
also that a partial septum narium is present, which is absent in Fergus 
and not a constant character among the others. 
Fig. 27. Skull of Branta canadensis hutchintii; right lateral view; life size. From a specimen in the 
author's collection. 
The lacrymal has the broad descending process, but not so enor- 
mously expanded as we find it in the Swans and in Glaucionetta. It 
will also be noted how this tends to approach the sphenotic process of 
the opposite side of the orbit, which it nearly succeeds in meeting in 
the Golden Eye. 
Again, the condition of the interorbital septum as it is generally 
formed among the Ducks and Geese is well exemplified in this Goose. 
Fenestraj occur in the region of the exit of the first pair of nerves, but 
the center of the plate is impervious. Attention is invited, too, to the 
form of the palatine, quadrate, and pterygoid on this lateral view. 
The crotaphyte fossa is small and inconspicuous, and confined entirely 
to the side of the head. As in all Anatidce, the entrance to the auricular 
chamber is thoroughly walled about with bone, without presenting any 
flaring wing-like extensions as we sometimes see in birds. 
The unusual size of the brain-case in Hutchin's Goose is, perhaps, 
better appreciated upon a direct posterior view than it is here on our 
lateral one. Comparatively speaking, it is far above, I think, the 
average for a bird of its size. 
Still regarding this skull from the aspect presented, and to make 
some of its characters still more evident by contrast, we will place it 
beside the skull of Mergus, already described above. We note the 
difference in the form of the bill; the presence of the cranio facial line 
in the Goose, while it is absent in the Merganser. Both have the nar- 
row depressions along the margins of the orbits for the nasal glands, 
but posterior to this the Goose has the dome like vault of the cranium 
so characteristic of the more highly organized types of the Anatidce, 
while we see that this region in the Merganser is much flattened. 
Regarding the skull from the under side, we are particularly to note 
the difference in form of the maxillo palatines, the palatine bodies, and 
the pterygoids. 250 
OSTEOLOGY OF ANSERES. 
The vomer varies but little among the genera of this order. When 
describing it for Mergus serrator it was said how its superior border 
was finished off by a thickened rib. I find in an immature specimen of 
Glaucionetta islandica that the most of this is contributed by the ascend- 
ing processes of the palatine on either side, each sending a delicate 
anterior process over the upper margin of the vomerine plate. In 
mature skulls of Ducks and Geese the sutural traces of this condition 
of affairs are obliterated, and from an examination of a skull of an adult 
Duck we would be very much inclined to think that this thickened 
upper rim of the vomer was a part of its own ossification. 
Fig. 28. Skull of Branta canadensis hutchinsii; 
rom above. Same specimen as Fig. 27; life size. 
Fig. 29. Skull of Branta canadensis hutchintii; 
basal view witli mandible removed; life size. 
Same specimen as Figs. 27 and 28. 
Seen from behind (Fig. 30), we find the plane of the periphery of the 
foramen magnum nearly at right angles with the basiscranii, as in 
Mergus ; but the chief feature that, strikes us here is, as already alluded 
to, the great superiority of the Goose over the Merganser in its more 
capacious brain case, which, of course, is indicative of the possession 
on the part of the former of a comparatively and correspondingly much 
larger encephalic mass. 
In comparing the characters of the skull in Fergus serrator with the 
corresponding ones as we find them in the ma jority of the Ducks, Swans, 
and Geese, I find them to differ in the following general particulars: 1888. 1 
PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
251 
The skull in Meryus senator: Osseous mandibles long and narrow; 
lacrymo frontal suture persistent; descending process of lacrymal spine- 
like; interorbital septum largely deficient at its center; mastoidal 
head of quadrate single; trochlem of mandibular foot of quadrate with 
their long axes placed nearly parallel with the long axis of the skull; 
maxillo palatines for their anterior halves meet 
in the median line, posteriorly they are pro- 
duced as distinct cyl ind riform processes with 
free extremities; pterygoids long, of equal 
width, and concave outward. 
As a rule, in the skull of Ducks, Swans, and 
Geese the osseous mandibles vary in length, 
but are always broad and of a lamellar struct- 
ure; lacrymo-frontal suture obliterated; de- 
scending process of lacrymal much expanded, 
with flat surface directed outward; interorbital 
septum very rarely shows a small central va- 
cuity (Glaucionctta); mastoidal head of quad- 
rate usually double; trochlem of mandibular foot of quadrate with their 
long axes placed nearly at right angles with the long axis of the skull; 
maxillo-palatines fuse in the median line for their entire lengths, no 
posterior processes; pterygoids short, straight, and much larger an- 
teriorly than they are at their proximal extremities. 
Fig. 30. Posterior view of skull 
of Uranta canadensis hutchinsii; 
inaudible removed; life size. 
Same specimen as Fig. 27 et seq. ON THE PROPER NAME OF THE GENUS LABRAX OF CUVIER. 
BY THEODORE GILL. 
Ill 1888 Professor D. S. Jordan, in the fifth and last edition of that 
excellent epitome, "A Manual of the Vertebrate Animals of the North- 
ern United States" (p. 13G), has resuscitated the genera Roccus and 
Morone for the American Labracime, and it was evidently his intention 
to retain them as genera distinct from their European relations. He 
has thus reverted to the views promulgated by Gill in 1861. A few 
words may be in place now as to the proper name of the European 
genus. Labrax can not be used, inasmuch as it had been previously 
employed by Pallas as well as Cuvier himself* for a genus of north 
Pacific fishes familiar to all American ichthyologists under the name 
Hex agr animus, and by the European chiefly designated as Chirus. In 
this dilemma, then, another name becomes necessary, and this may 
be found in Dicentrarchus, a designation proposed originally for the 
Labrax punctatus of Geoffroy St. Hilaire under the belief that that 
species had, as represented, only two anal spines. It has been since 
shown, however, by Steindachner and others that the character in 
question was illusive and void, and that the species in reality is a typ- 
ical Labrax, and very closely related to the common Labrax lupus of 
the Mediterranean. The name Dicentrarchus thus becomes available 
for all the European species of the genus, and inasmuch as the term is 
inappropriate with the etymology which might naturally be attributed 
to it, it can be interpreted as referring to another feature and be im- 
agined as composed of double (in sense of 2), xevrpov, spine, and 
chief, in allusion to the renown and excellence of the fish and to the 
two kinds of armature or spines which surround the pre-opercular 
margin and distinguish them from their American relations, as well 
as the two spines which arm the operculum and on which the genus 
was especially distinguished from Perea by Cuvier. The specific name 
of the typical species will then be Dicentrarchuspunctatus. 
The external differences between the genera Roccus and Morone are 
supplemented by cranial ones, and such are diagnosed by the author 
in the report on ichthyology in Simpson's Explorations Across the 
Great Basin of Utah in 1859 (1876, pp. 389, 396). 
* Cuvier, liegne animal, v. 2 (1817), p. 2G8. 
Proceedings U. S. National Museum, vol. xi, 1888.