124 COXTRIBUTIOXS TO NORTH AMERICAN ICHTHYOLOGY IV. 



12S. P. viB'esceMS Cope. 



Body elong-ate, compressed, tlie caudal peduncle contracted. Head 

 sliort, wide, 5 in length. Muzzle obtuse, little projecting. Upper lip 

 wide ; lower lip full, emarginate. Jaws with well- developed cartilagi- 

 nous sheaths. Scales much reduced in size forwards. Dorsal rays 10; 

 ventral 9 5 scales 18-103-lG. Color olive; lower surface yellow. Head- 

 waters of Arkansas Eiver. 



(Cope, Wheelers Expl. W. lOOfcli Mer. v, 675, 1876; Jordan, 1. c. 182.) 



64.— CATOSTOrfltJS Le Sueur. 



Bucliers. 



{Hijlomiizon Agassiz ; Acomtis and Minomiis Girard.) 



(Le Sueur, Jouru. Acad. Nat. Sci. Pliila. i, 89, 1817 : tyiie Cyprinus catostomus Forster = 

 Catosloitms loiif/irostrum Le Sueur.) 



Head more or less elongate, its length ranging from 3.L to 5 times in 

 that of the body. Eye usually rather small, high up, and median or 

 more or less posterior in position. Suborbital bones narrow, longer 

 than broad, much as in Moxostoma. Fontanelle always present, usually 

 widely open, in two species reduced to a narrow slit, but never wholly 

 obliterated. Mouth rather large, always inferior, and sometimes nota- 

 bly so ; the upper lip thick, protractile, papillose ; the lower \\p greatly 

 developed, with a broad free margin, deeply incised behind, so that it 

 forms two lobes, which are often more or less separated. Mandible 

 horizontal, short, not one-third the length of the head and not reaching 

 to opposite the eye. Lower jaw usually without distinct cartilaginous 

 sheath. Opercular apparatus moderately developed, not rugose. Pha- 

 ryngeal bones moderately strong, the teeth shortish, vertically com- 

 pressed, rapidly diminishing in size upwards, the upper surface of the 

 teeth nearly even or somewhat cuspidate. Body oblong or elongate, 

 more or less fusiform, subterete, more or less comi^ressed. Scales com- 

 paratively small, typi(*ally much smaller and crowded anteriorly, the 

 number in the lateral line ranging from about 50 to 115, the number in a 

 transverse series between dorsal and ventrals from 15 to 40. Lateral line 

 well developed, straightish, somewhat decurved anteriorly. Fins vari- 

 ously developed. Dorsal with its first ray nearly midway of the body, 

 with from 9 to 14 developed rays. Anal fi u short and hi gh , with probably 

 always 7 developed rays. Ventrals inserted under the middle or poste- 

 rior part of the dorsal, typically with 10 rays ; in one subgenus usually 

 9 ; the number often subject to variation of one. Caudal fin usually 

 deeply forked, the lobes nearly equal. Sexual i)eculiarities not much 



