31. CYPRINID^l COCIILOGNATHUS. 161 



82. COCIILOGNATIIUS Baird & Girard. 



(Baird & Girard, Proc. Acad. Nat. Sci. Phila. 1654, 158 : type CocUlognathus ornatus B. 

 &G.) 



This genus lias the general character and appearance of Ryborliynclms, 

 the dentition and the structure of the fins being the same ; the teeth, 

 however, rather more strongly hooked and with deeper grinding sur- 

 face. It differs in the structure of the jaws, which are provided each 

 with a hard cutting plate, to all appearance precisely like the Diodonti- 

 dce, the sharp bony edge being surrounded by the usual lip. First ray 

 of dorsal separated by membrane, and spine-like, as in Hyborkynckus 

 and Pimepliales. Alimentary canal short. Peritoneum white. Pseudo- 

 branchiae present. Lateral line complete. Anal fin small. (/. 

 shell; fvdOoq, jaw ; the covering of the jaws being hard, like shell.) 



196. C. oriltll Baird & Girard. Hard-mouth Minnow. 



Appearance, dorsal fin and coloration essentially as in Hyborliynclius 

 notatus. Body moderately elongate. Head rather long. Scales com- 

 paratively large. Dorsal fin over the ventrals, rather high. Anal fin 

 quite small. Caudal fin short. Dorsal fin with a black spot near the 

 base in front and a dusk}* blotch behind. The dorsal spin conspicu- 

 ous. Caudal fin with a dusky median band, in front and behind which 

 is a pale area. A dusky lateral baud. Snout tuberculate in spring 

 males, as in Hyborliynchus. Head 4 ; depth 4^. D. 8 ; A. 6 ; Lat. 1. 40 ; 

 teeth 4-4. L. 3 inches. Eio Grande. A singular little fish, with the 

 mouth resembling that of Chondrostoma or AcrochiluSj but the structure 

 otherwise resembling neither. 



(Baird & Girard, Proc. Acad. Nat. Sci. PMla. 1854, 158; Guuther, vii, 187.) 



197. C. MguUatus Cope. 



" A fish of rather uniform diameter and deep caudal peduncle. The 

 head is oblong and rather wide above. The muzzle has a decurved pro- 

 file and terminal mouth. The orbit is large, 3| in head, a little less 

 than muzzle and than iuterorbital space. Head wide behind and flat 

 above. The infraorbital bones are narrow, while the preorbital is large. 

 with convex inferior and concave superior border. Maxillary not quite 

 reaching line of orbit. Ventral fins inserted opposite second or third 

 dorsal ray, reaching to vent. Anal fin small. Pectorals reaching three- 

 fifths to ventrals. Color silvery, without dark markings, except a black 

 spot at the base of the caudal and on the anterior rays of the dorsal. 

 Head 5 in length, with the caudal fin j depth a little less. D. 8 ; A. 7 ; 

 scales 7-34-? L. 2J inches. Trinity Eiver, Texas." (Cope, MSS.) 

 Bull. Nat. Mus. No. 1G - 11 



