30. CATOSTOMID^ BUBALICHTUYS. 115 



60.— BIJBAI.I€IITII1 S Agassisi. 

 Buffalo-Jishes. 

 (Agassiz, Amor. Jonra. Sci. Arts, 1855, 192: type Carpiodcs nrus Ag.) 



Head moderate or rather large deep and thick, its superior outline 

 rapidly rising; its length about 4 in that of the body. Eye moderate, 

 median or rather anterior in j)osition. Suborbital bones comparatively 

 narrow. Fontanelle always present and widely open. Mouth moderate 

 or sTiiiill, more or less inferior; the mandible short, little oblique, or 

 typically quite horizontal ; the mandible less than one-third the length 

 of the head ; the premaxillaries in the closed mouth below the level of 

 the lower part of the orbit. Lips rather thin, thicker than in Ictiobus, 

 the upjier i)rotractile, narrow, plicate, the jilicse sometimes broken ux> 

 into granules ; lower lip comparatively full (for a buffalo- fish), faintly 

 I)licate, the plicae broken up into granules, the lower lip having the gen- 

 eral fi -shaped form seen in Carpiodes. Jaws without cartilaginous 

 sheath. Muciferous system well developed. Opercular apparatus well 

 developed, but less so than in Ictiohvs; the operculum strongly rugose ; 

 isthnnis moderate. Pharyngeal bones triangular, with large teeth, 

 which increase in size from above downwards. Teeth compressed, their 

 grinding edge blunt, slightly arched in the middle, and provided with a 

 little cusp along the inner margin, which is hardly detached from the 

 crown, and does not rise above the surface. Gill-rakers of anterior arch 

 slender and stiff above, growing shorter downwards. Body ovate or 

 oblong; the dorsal outline more or less arched; the sides of the body 

 compressed ; the ventral outline curved also, but to a less degree. Scales 

 very large, about equal over the body, their posterior ontlines somewhat 

 serrate. Lateral line well developed, nearly straight, with 35-42 scales ; 

 12-14 in a cross-series from ventrals to dorsal. Dorsal fin beginning 

 near the middle of tie body, somewhat in advance of the ventrals; its 

 anterior rays elevated, their height about equal to half the base of the 

 fiu, the number of rays in the dorsal tin ranging from 25 to 30. Caudal 

 fin well forked, the lobes about equal, not falcate. Anal fin comi)ara- 

 tively long and rather low, of 8 or 9 developed rays. Ventrals moder- 

 ate, 10-rayed. Pectorals ratlier short. Sexual peculiarities, if any, un- 

 known. Coloration dull dark brown, nearly plain, not silvery. Fins oli- 

 vaceous or more or less dusky. Air-bladder with two chambers. Size 

 quite large. This genus is closely related to Ictiohus, difiering only in 



