FISHES — CTPRINIDAE EXOGLOSSUM. 255 



HYBOPSIS, Agass. 



Gf.n. Chak. — Body elongated, compressed, sub-fueiform in profile, covered with rather large scales. The lateral line being 

 straight along the middle of the flanks. The head is of moderate size, sub-conical and rounded upon the snout, which protrudes 

 beyond the lower jaw. A barbel, inserted upon the anterior margin of the posterior extremity of the maxillary, may be seen at 

 the angle of the mouth. The eyes are large, the isthmus narrow. The dorsal is a little higher, and the anal deeper, than long. 

 The insertion of the ventrals takes place opposite the second ray of the dorsal, hence very nearly under its anterior margin. 

 The tail is deeply furcated. The pharyngeal bones have the same form and appearance as in Hudsonius; the teeth are likewise 

 of the same kind (bruising) and type (hooked with a grinding surface), but more irregular yet. Sometimes not hooked, the 

 grinding surface contorted and nearly absent, or even resembling a truncated cone. They are disposed upon a double row of 

 four and one: 1 | 4 — 4 | 1, or | 4 — 4 | 1. 



Syn. — Hybopsk, Agass. in Amer. Journ. of Sc. Second series, XVII, 1854, 358. — Grd. in Proc. Acad. Nat. Sc. Philad. 

 VIII, 1856, 210. 



This genus, it will appear, is intimately related to Hudsonius, from whicli it chiefly differs 

 hy the presence of barbels at the angle of the mouth, and by its straight lateral line also. 



It was left rather vaguely defined by its author, for there are many genera in which "the 

 mouth is protractile downwards, after the fashion of Catostomus," with the lips neither swollen 

 nor thickened. And many other genera, too, in which there is "only four or five compressed 

 and hooked teeth in each main row, and one or two in a second row." What is really of 

 generic value is left for us to conjecture, since we are not in possession of its typical species. 



The generic characters which we now oifer are based upon Leuciscus storerianus and a new 

 species from Alabama (Hybopsis ivinchelli, Proc. Acad. Nat. Sc. Philad. VIII, 1856, 211), and 

 should they prove generally distinct from Hybopsis gracilis, Agass., a new name will have to 

 be coined for our species. 



TEIBE OF ALBUENI. 



The genera brought together in this tribe are numerous, and quite as diversified in their 

 dentition as in the former group. They differ from the latter by the absence of barbels. As 

 in the preceding, the teeth are of the hooked types, with or without grinding surface {Denies 

 uncinato-suhmolares et uncinato-subconici), mostly of the raptatorial kind {Denies raptatorii). 

 In the majority of cases, the teeth are disposed upon a double series also. 



This group was first distinguished in the "Proceedings of the Academy of Natural Sciences 

 of Philadelphia, vol. VIII, 1856, 190." 



EXOGLOSSUM, Rafin, 



Gen. Char. — The body is elongated, sub-cylindrical, somewhat compressed. The head is sub-conical, flattened at the 

 occiput, and terminated by a blunt snout. The mouth is sub-terminal, opening downwards and forwards, the lower jaw being 

 shorter than the upper and not surrounded by the lips around its symphysis, the lips being largely developed at the angle of the 

 mouth and along the upper jaw also. The eye is of moderate size. The isthmus is wide. The origin of the ventrals is situated 

 opposite the anterior margin of the dorsal or posterior to it. The caudal is furcated. The scales are rather large. The 

 pharyngeal bones are exiguous, very slender upon their inferior branch, hardly diluted above. The teeth are of the raptatorial 

 kind of the hooked type, without grinding surface, instead of which a sharp, but not crenated, edge. They are disposed upon a 

 double row of one and four, thus: 1 | 4 — 4 | 1. 



Stn. — Exoglossum, Rafin. in Journ. Acad. Nat. Sc. Philad. I, 1, 1818, 419. — Hkckel, in Russeg. Reisen, I, ii, 1842,1 023. — 

 Cuv. & Val. Hist. nat. Poiss. XVII, 1844, 480. — Storer, Synops. 1840, 176. — Agass. in Amer. Journ. of 

 So. 2d series, XIX, 1855, 215.- Gbd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 191. 



