30. CATOSTOMIOrE BUBALICHTIIYS. 115 



6O. BUBAL.ICHTHYS Agassi*. 



Buffalo-fishes. 

 (Agassiz, Amer. Journ. Sci. Arts, 1855, 192 : type Carpiodcs urus 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 position. Suborbital bones comparatively 

 narrow. Fontanelle always present and widely open. Mouth moderate 

 or small, 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 preniaxillaries in the closed mouth below the level of 

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

 the upper protractile, narrow, plicate, the plicre sometimes broken up 

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

 plicate, the plicre broken up into granules, the lower lip having the gen- 

 eral p| -shaped form seen in Carpiodes. Jaws without cartilaginous 

 sheath. Muciferous system well developed. Opercular apparatus well 

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

 isthmus 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 outlines 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 

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

 fin well forked, the lobes about equal, not falcate. Anal fin compara- 

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

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

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

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

 quite large. This genus is closely related to Ictiobus, differing only in 



