12-4 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



128. P. vii'csccns Cope. 



Body elo i-ate. compressed, the caudal peduncle contracted. Head 

 >!iort, wide, .". iii length. Muzzle obtuse, little projecting. Upper lip 

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

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

 ventral!); se ales 18-103-16. Color olive; lower surface yellow. Head- 

 waters of Arkansas River. 

 (Cop.-, WIi.-i-l.-r'.s Exiil. W. lUOih Mer. v, 675, 1876; Jordan, 1. c. 182.) 



61. CATOTO:?IU Lc Sueur. 



Suckers. 



(Hyloiy:on Agassiz ; Acomus and Minomua Girard. ) 



(Lc Siteur, Joiirn. Arad. Nat. Sci. Phila. i, 89, 1817: type Cyprinm catoatomus Forster = 

 CatostomHs longirostrum Le Sueur.) 



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

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

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

 than broad, much as in Moxostoma. Foutanelle 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 lip greatly 

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

 form ; 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- 

 r\!igeal bones moderately strong, the teeth shortish, vert ically com- 

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

 teeth nearly even or somewhat cuspidate, liody oblong or elongate, 

 more or less fusiform, siibterete, more or less compressed. Scales com- 

 paratively small, typically much smaller and crowded anteriorly, the 

 number in tin- lat -ral line ranging from about .")0 to 115, the number in a 

 transverse series between dorsal and veiitrals from !." to 10. Lateral line 

 well developed, straight ish, some\vl:at deciirved anteriorly. Fins vari- 

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

 with from !) to 1 1 developed ra\ s. Anal (in short and high, with probably 

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

 rior part of the dors, il, typically with 10 rays; in one snbgenns usually 

 '.': the number often subject to variation of one. Caudal I'm usually 

 deeply forked, the lobes nearly equal. Sexual peculiarities not muck 



