CATOSTOMID^E. C1X. 323 



27 inches; weightlSIbs. Mississippi Valley (described 

 from specimen from Wabash R.) 



** Body shorter, considerably compressed; the dorsal region 

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



2. /. cyanellus, Nelson. BLUE BUFFALO. Head 3 

 in length; depth 2; 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. I, 30; lat. 1. 38. Illinois River. 



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

 bubalus; 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. /. isehyrus, 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 1^- in its length; width of head 1^; eye 6|- in head, 

 If 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." (Nelson.) Rivers of Illinois. 



//. BUBALIGHTHYS, Agassiz. BUFFALO FISHES. 



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

 BUFFALO. Body much less elevated and less com- 

 pressed than in B. bubalinus, the back not at all 

 carinated; axis of body over the ventrals about at the 



