31. CYPRINID.E 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. 



(? Gobio plumbers Agassiz, Lake Superior, 366 : Leucosomus dissimilis Girard, Proc. 

 Acad. Nat. Sci. Phila. 1856, 189, and U. S. Pac. R. R. Surv. x, 250 : Nocomis milncri 

 Jordan, Bull. U. S. Nat. Mus. x, 64, 1876 ; Jordan, Bull. Hayden's Geol. Surv. Terr. 



iv, 784, 1878.) 



343. C. prosthcmius (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 ; depth 5. D. 8 ; A. 7 ; scales 11-63-8, somewhat crowded 

 anteriorly; teeth 2, 4-4, 2. L. 6 inches. Upper Great Lakes. 



(Ceratichthya prosthemius Cope, Cypr. Pcnn. 1866, 1565: Ceratichthys plumbeus Gun- 

 trier, vii, 442.) 



** Scales rather large, about 50 in the lateral line and 10 in a transverse series. 



344. C. pliysignatliaas (Cope) Jor. 



Body slender, the caudal peduncle stout. Head wide and depressed. 

 Dorsal outline little arched, the profile descending steeply to the lip. 

 Lower jaw included, maxillary reaching anterior border of orbit. Bar- 

 bels well developed. Eye J 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 plumbeous lateral band ; fins plain. 

 Head 3; depth^. D. 8; A. 8; scales 5-49-4; teeth 2, 4-4,2. Arkansas 

 Eiver at Pueblo. (Cope.) 



(Ceratichlhys physignathus Cope, Wheeler's Expl. W. 100th Mer. v, 651, 1876.) 



94. PLATYGOBIO Gill. 



Flat-headed Chubs. 

 (Gill, Proc. Bost. Soc. Nat. Hist. 1861: type Pogoniclitliys 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 large, (^aru?, broad ; Latin 

 gobio, a gudgeon; the broad, Hat head resembling the head of a Gilo,.) 



345. P. gracilis (Rich.) Gill & JOT. Flat-headed Chub. 



Body rather elongate, somewhat compressed, little elevated. Head 

 small and short, its upper surface very broad and depressed, the inter- 



