31. CYPRINID^ PLATYGOBIO. 219 
depth 4^. D. 8; A. 8; scales 11-68-7 ; teeth 2, 4-4, 2. L. 6 inches. 
Lake Superior to Upper Missouri region ; probably abundant. 
(? Gohio plumhens Agassiz, Lake Superior, 366 : Lcucosomus dissimilis Girard, Proc. 
Acad. Nat. Sci. Pbila. 1856, 189, and U. S. Pac. R. R. Surv. x, 250 : Kocomis viilncri 
Jordan, Bull. U. S. Nat. Mus. x, 64, 1876 ; Jordan, Bull. Hayden’s Geol. Surv. Terr, 
iv, 784, 1878.) 
343. C. prostlieiniiis (Cope) Jor. 
Body fusiform, rather slender. Head small, the muzzle abruptly de- 
scending. Mouth rather small, somewhat oblique, the maxillary not 
reaching to the orbit. Eye 4 in head. First ray of dorsal opposite ven- 
trals. Color dusky; a plumbeous lateral band; white below; fins plain. 
Head 5; depths. D. 8; A. 7; scales 11-63-8, somewhat crowded 
anteriorly; teeth 2, 4-4, 2. L. 6 inches. Upper Great Lakes. 
{Ceratichthi/s prosthemius Cope, Cypr. Penn. 1866, 385: Ceratichthys' plumbeus Giin- 
ther, vii, 442.) 
** Scales rather large, about 50 in the lateral line and 10 in a transverse series. 
344. C. piiysignatOaus (Cope) Jor. 
Body slender, the caudal peduncle stout. Head wide and depressed. 
Dorsal outline little arched, the prohie descending steeply to the lip. 
Lower jaw included, maxillary reaching anterior border of orbit. Bar- 
bels well developed. Eye If in head, 1;} in muzzle. Twenty -three rows 
of scales in front of dorsal. Dorsal fin inserted in front of ventrals. 
Olivaceous above, white below ; a iilumbeous lateral band ; fins plain. 
Head3|; depths. D.8; A. 8; scales 5-49-4 ; teeth 2, 4-4, 2. Arkansas 
River at Pueblo. {Gop&.) 
(Ccratichihys physignathus Cope, Wheeler's Expl. W. lOOth Mer. v, 651, 1876.) 
04.— PLATYGOBIO Gill. 
Flat-headed Glmhs. 
(Gill, Proc. Bost. Soc. Nat. Hist. 1861: type Pogonichthys communis Grd.) 
Body rather elongate, somewhat compressed. Head rather short, 
broad and depressed above. Mouth normal, rather large, subter- 
minal, with a well- developed barbel at its angle, at the extremity of 
the maxillary. Scales large. Lateral line continuous. Dorsal in- 
serted anteriorly, rather in front of the ventrals. Teeth 2, 4-4, 2, with 
rather narrow grinding surface. Size largo. broad ; Latin 
gobio, a gudgeon; the broad, fiat head resembling the head of a Gila.) 
345. P. gracilis (Rich.) Gill & Jor. — Flat-headed Chub. 
Body rather elongate, somewhat compressed, little elevated. Head 
small and short, its upper surface very l)road and depressed, the inter- 
