THE NOMENCLATURE OF THE MYLIOBATID2E OR AETO- BATIILE. By Theodore Gill, m. d., ph. d. In 1888, President Jordan proposed, for very plausible reasons, to revive Blainville’s name Aetobatus (used in the form Aetobatis) for the genus long known as Myliobatis.* I hastily followed him and have repented at leisure. My reasons for now dissenting are as follows: AETOBATUS. Blainville, in 1816, published a new scheme for the classification of the “ Selaca” or Plagiostomes (which he had studied with Mr. Prevost) and divided them into three genera or families: “ I. Gen. aut Fam. Raia;” “II. Genus aut Fam. Squatina,” and “III. Genus aut Fam. Squalus.” The rays were subdivided into 7 groups bearing generic names: Dasybatus f =Raiidce\, Trygonobatus \=Dasybatidce without Urolophus], Aetobatus \=Myliobatidce], Dicerobatus [=Mantidce], Leio- batus i f = Urolophus], Narcobatus f = Torpedinidce), Rhinobatus [ == Rhino- batidce], and Pristobatils [=Pri8tidce+Pristiophoridce]. Blainville gave a full and excellent diagnosis of Aetobatus, and included “11 nominal species of Myliobatids in the genus. They were as follows:| Vulgaris (M. aquila%); Obtusus (?); Flagellum (Ae. flagel- lum) ; Lobatus (Rhinoptera I); Sinensis (?); Nichofii [M. Nieuliofii); Fili- * President Jordan was perfectly logical in bis .conclusions. Aetobatus was prior to Myliobaiis and covered exactly the same group. Remembering this, but not having Blainville’s memoir on hand at the time, temporarily forgetting the entire course of reasoning which had previously influenced me (herewith outlined), and fearing that prejudice in favor of accepted usage might have unduly prevailed in my mind, I noted the change, intending to consult Blainville’s papers before publication, but the work could not then be found. The only reason why Aetobatus had not been revived before was because it was supposed to be subsequent to Myliobaiis. (See Gray’s List, p. 128, and synonymy, where Myliobaiis is erroneously attributed to “ Dum. Zool. Anal., 1806.”) tLeiobatus Bl. was anticipated by Leiobatus Kaf. (Car., p. 16, 1810) =Ithinobatus. | The initial capitals are repeated from Blainville’s memoir. Proceedings National Museum, Vol. XVII— No. 990. 112 NOMENCLATURE OF THE MYLIOBA TIDJE—GILL. VOL. XVII. caudatus (?); Hamatus (f); Ocellatus (Ae. narinari?)-, Narinari (Ae. narinari); Forsteri( ?) The only species of this list that can he certainly identified by name is the narinari, the type of the Mullerian genus Aetobatis. By assum- ing that Nichojii is a misprint for Nieuhofii, we are led to another prob- able identification. The other specific names are-new and can only be guessed at; the results of such guesses are given in brackets after the several names, when there are good grounds for guessing. But the genus must be determined by the known species named and those belong only to the genus Aetobatis, M. & H. MYLIOBATIS. Cuvier in 1817, adopted from manuscript of Dumeril the name Myliobatis for the same group called by Blainville Aetobatus. In this course he was followed by almost all succeeding naturalists. GENERA OF MYLIOBATIDES. Miiller and Henle in 1838 distributed the species combined under the names Aetobatus or Myliobatis into three genera, Myliobatis, Aetobatis, and Rhinoptera (Cuv., 1820). They ascribed to themselves the name Aetobatis. This arrangement was generally adopted by later writers. AGASSIZ’S VIEWS. Agassiz in 1843 (Poiss. Fos., nr, p. 325), took the correct view of nomenclature in the following passage: 2°, Du genre Aetobatis M. et H. M. de Blainville le noin d’Aetobatis l’ensemble des Mouriues connues & oil il publiait son ouvrage. Ce genre n’6tait done alors qu’un simple syuonyme du genre Myliobates de M. Dumdril.' Plus tard MM. Miiller et Henle subdivisereut ce gronpe en plusieurs genres, il conserverent le nom Myliobates an genre dont le Raja aquila des auteurs peut etre comme le type, et ils re- streignirent le nom de Aetobatis an genre dont le Narinari de Margraf est l’esp&ce la plus anciennement connue. This, it seems to me, is a perfectly legitimate view and use of the two names. Both names, Aetobatus and Myliobatis, might have been retained for different sections of the old genus, if no other considerations had forbidden. Both of those names, however, as President Jordan has reminded me, were anticipated by a name given by Rafinesque in 1810. CEPHALEUTHERUS. Rafinesque, in his “ Indice d’Ittiologia Siciliana,” has a genus Cepha- leutlierus interposed between his Mobula (= Gephaloptera Dum.) and Uroxis (Trygon auct.), which, according to Dr. Jordan, is a Myliobatis. * A leas equivocal expression would l»e that Myliobatis was a synonym of Aetobatis since the former name (1817) was subsequent to the latter (1816). ritOCEEDTXGS OF THE NATIONAL MUSEUM. 113 It is not, however, mentioned byDoderlein in his very full synonyms of the Myliobatids of the Mediterranean, and the hook in question cannot be found. While I have little doubt that Dr. Jordan is correct in his identification and that the name Cephaleutlierus should be taken for Myliobatis, I defer doing so until l am able to consult the Indice or a copy of it. Meanwhile I retain the name Myliobatis, but adopt for the family Aetobatidce. SYNONYMY. The principal synonyms of the family and its primary divisions are as follows: Family A k t o b a t i d m . =Mj/Uobalide8, Muller & Henle, Syst. Beschreib. Plagiostomen, p. 176, 1841. =Myliobatidat, Adams, Man. Nat. Hist., p. 87, 1854. =Myliobatidce, Richardson, Encycl. Brit., 8. e