GEOLOGICAL SURVEY OF THE TERRITORIES. 437 



PTYCHOSTOMUS BUCCO, (COPE ;) sp. IIOV. 



A stout species, with, a head short and particularly wide through the 

 opercula. Lips thin, the inferior consisting of lateral lobes inclosing a 

 Y-shaped interval. Superior lip narrow, not pendent. Muzzle slightly 

 projecting, subtruncate in profile. Eye large, 3.5 times in length of 

 head, 1.2 in muzzle, and nearly .75 of interorbital width. Front and 

 vertex flat; width behind orbits 1.75 times in length of head. Head 

 one-fourth length without caudal, and equal to depth. Scales, 6-40- 

 5. Eadii, D. II. 12 ; A. II. 7 ; V. 9. Dorsal nearly median on superior 

 outline. Pharyngeal teeth typical, i. e., pectiniform, with slightly prom- 

 inent inner angle. 



Color uniform ; dorsal fin dusky. Total length of young. M. .117 ; to 

 opercular margin .0255 ; to ventral fins .0545. From St. Josephs, Mis- 

 souri. 



This species is allied most closely to the P. collapsus, Cope. This is a 

 still stouter species, the depth entering the length only 3.5 times ; the 

 eye is smaller, being .2 of the head's length. The Oatostomus suekleyi 

 resembles it, but is more slender, and belongs to another genus. The 

 P. bucco is named from the interopercular width of the head. 



Cyprinidce. 



(Campostoma anomalum, Eaf. Icth. Ohiensis.) (Rutilus.J Agas- 

 siz, Cope; Trans. Amer. Philos. Soc, 1866 ? 396. — Probably from the 

 head- waters of the Platte Eiver. 



• coliscus parietalis, (cope ;) gen. et. sp. nov. 



Char, genericus : Group IV. of the tribe Epicysti, (Trans. Amer. Phil. 

 Soc, 1866,) and therefore with cultriform teeth arranged 4-4, and elon- 

 gate alimentary canal, coiled many times below the swim bladder. The 

 lateral line is almost entirely wanting, and the dorsal fin originates 

 above a point in front of the ventrals. The lips are exceedingly atten- 

 uated, and the mouth directed upwards. Allied to Hybognathus, Agass. 



Char, specijicus : Head wide ; especially behind, contained 4.25 times 

 in the length without caudal fin. Muzzle obtuse; lips equal ; mouth 

 descending obliquely, the end of the maxillary not quite reaching the 

 line of the anterior margin of the orbit. Eye 3.6 times in length of 

 head; 7 times into muzzle, and 1.5 times into interorbital width. Scales 

 small; 1. tr. 14; 1. long. 42; seven behind operculum, bearing tubes of 

 the lateral line. Eadii D. I. 7 ; A. 1. 8 ; V. 9. General form moderately 

 elongate ; dorsal fin intermediate between end of muzzle and basis of 

 caudal. Depth at dorsal, 4.6 times in length without caudal. Subor- 

 bital bones slender. Color everywhere white, silver on the sides of the 

 head. Length, M. .0432. From the Missouri Eiver near to St. Josephs. 

 (Mus, Chicago Acad. Sciences, No. 575.) 



HYBOPSIS MISSURIENSIS, (COPE ;) Sp. nov. 



Belonging to group B, i. e., with teeth 4-4, and mouth inferior 

 Form stout, with large head and thick caudal peduncle. Head 3.75 

 times into length without caudal fin; scales, 5 — 31-2 — 3. 



Dorsal outline a little arched ; depth 4.5 times in length, without 

 caudal fin. Eye three times in length of head, equal muzzle, four-fifths. 



