116 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



the somewhat strouger teeth. The two genera, with perhaps Carpiodcs 

 also, should probably be reunited. Three species are known, two in the 

 United States and a third in Central America.* {[iooiSaXo:;, buffalo; 



i/Ouc, fish.) 



114. B. uras Ag. — Big-mouthed Buffalo. 



Body much less elevated and less compressed than in B. alfus, 

 the back not at all carinated ; axis of body above ventrals about at the 

 lateral line, and but very little farther from the dorsal outline than from 

 the ventral ; depth 3-34 ^^ length. Head very stout, strongly trans- 

 versely convex, thicker, larger, and less pointed than in the other, 

 about 4 in length. Eye about equal to snout, 5^ in head, much smaller 

 than in B. altus. Mouth large, considerably oblique, opening well for- 

 wards. Mandible longer than eye. Premaxillary somewhat below sub- 

 orbital. Dorsal fin lower and less rapidly depressed than in the next, 

 the longest ray scarcely* half the length of the base of the fin. Anal fin 

 rounded ; its rays not rapidly shortened ; the middle ones not much 

 shorter than the longest. Colors very dark; fins all black. Scales 

 8_41_7j D. 30; A. 10. Mississippi Valley ; in the larger streams. 



(Carpiodcs urus Agassiz, Amer. Journ. Sci. Arts, 1854, 355: BulaUclitlujs urus, niger, 

 et honasus Agassiz, Amer. Journ. Sci. Arts, 1855,193-195; Jordan, 1. c. 209.) 



115. B. attllS Nelson. — SmaU-mouthed Buffalo. 



Body considerably elevated and compressed above ; the dorsal region 

 subcarinate ; belly thicker ; depth 2|-2f in length ; axis of body aboA^e 

 the ventrals, below the lateral line, and nearly twic^e as fiir from the back 

 as from the belly. Head moderate, triangular in outline when viewed 

 from the side, 4 in length. Eye equal to snout, 4-5 in length of head, 

 much larger than in B. nrus. Mouth quite small, notably smaller and 

 more inferior than in B. tirus. Mandible about equal to eye. Dorsal 

 fin elevated in front and rapidly declined, the highest ray reaching 

 much beyond the nuddle of the fin, the seventh ray about half the 

 length of the third or longest. Anal rays rapidly shortened behind, the 

 middle rays much shorter than the first long ones. Scales 8-39-G; 



*J3. meridiovalis (Giintlier) Jordan. Moutli small, inferior, slightly corrugated. 

 Depth 3^3i^ in length. Head 4-4-}, not much longer than high, l^ye rather small, 

 one-fifth of the length of the head and two-tifths that of the snout. Suborbitals nar- 

 row. Anterior dorsal rays not much produced, shorter than the head. Caudal forked. 

 Origin of ventral vertically beloAv the fourth dorsal ray. Pectoral fin not extending 

 to ventrals. There are 5 longitudinal series of scales between the lateral line and 

 the root of the ventral. Coloration uniform. Scales 7-38-7 ; D. 29 ; A. 10. Rio Usu- 

 macinta, Guatemala. {Giintlier.) {Sderognatlms mcrldionalis Giinther, vii, 23.) 



