CATOSTOMID^E. CIX. 323 



27 inches; weight 15 fibs. Mississippi Valley (described 

 from specimen from Wabash R.) 



** Body shorter, considerably compressed; the dorsal region 

 elevated. (These three the young of the preceding!) 



2. /. cyanelius, Nelson. BLUE BUFFALO. Head 3J 

 in length; depth 24-; eye 4^ in head; longest dorsal ray 

 reaching 18th; head very short, high and thick; mouth 

 quite small, oblique, somewhat overlapped by the obtuse 

 snout; insertion of dorsal rather anterior; steel blue, 

 paler below; D. T, 30; lat. 1. 38. Illinois River. 



3. /. rauchii, Ag. " Dorsal much higher than in I. 

 bubal its; all other fins much larger and scales not higher 

 than long." (Ag.) Mississippi River, Burlington, Iowa. 

 An unrecognized species. Specimens in my collection 

 from near Burlington agree with I. cyanellus, except 

 that the insertion of the dorsal is midway. 



4. /. ischyrus, Nelson. HEAVY BUFFALO. "This is a 

 very stout and heavily built species; depth 2^- in length; 

 head extremely broad between the eyes and but slightly 

 convex; its length 3^ times in length of body; snout 

 short and rounded, opercular apparatus large; depth of 

 head 14- in its length; width of head 1-J; eye 6f in head, 

 ! in snout, 4 in interorbital space; caudal peduncle a 

 little deeper than long; scales 7 37 7, nearly uniform, 

 a little crowded anteriorly, finely punctate; fins all 

 small; dorsal I. 27; A. I, 8; bluish-olive above, yellow- 

 ish below; fins blackish.*' (AWtfo/*.) Rivers of Illinois. 



//. BUBALICHTHYS, Agassiz. BUFFALO FISHES. 



1. B. urus f Ag. BLACK BUFFALO. BIG -MOUTHED 

 BUFFALO. Body much less elevated and less com- 

 pressed than in _/?. bubaUmix, the back not at all 

 carinated: axis of body over the ventrals about at the 



