30. CATOSTOMID.^: CHASMISTES. 
131 
series. Depth 4i-5 in length ; head 4-4.J. Eye rather small, 44 to 5 
in head. Color olivaceous 5 sides with brassy Instre ; belly white ; back 
brown, with several dark cross-blotches, irregularly arranged, these 
becoming obsolete in old individuals; lower tins dnll red, with some 
dusky shading ; young considerably variegated, the sides spotted. Size 
large; maximum length about 2 feet. New York to Alabama and 
Kansas ; abundant. Ascends streams to spawn early in spring. 
(Le Sueur, Journ. Acad. Nat. Sci. Phila. 1818, 102 : Hiilomiizon nijricans Agassiz, 
Amer. Jouru. Sci. Arts, 1855, 205 ; Giinther, vii, 17 ; Jordan, 1. c. 1G2. ) 
65.— CaiASMB§TE§ Jordan. 
(Jordan, Bull. Hayden’s Geol. Surv. Terr, iv. No. 2, 417, 1878 : type Chasmisics liorus 
J or. ) 
Head disproportionally large, forming more than one-fonrth of length, 
broad and flattish above ; sides of head vertical, slightly directed in- 
wards, the breadth through the cheeks less than the breadth above the 
eyes. Eyes small, high up, rather posterior. Month extremely large, 
terminal, the lower jaw in the closed month being very oblique, placed 
at an angle of about 45 degrees. The lower jaw very long and strong, 
its length more than oue-tbird the length of the head, nearly half the 
length of the head in the adult, its tij), when the mouth is closed, about 
on a level with the eye. Upper jaw very imotractile. Upper lip very thin 
(for a sucker), and nearly smooth. Snout elevated above the rest of the 
head, the iiremaxillary spines usually forming a conspicuous nose. Lower 
lip moderate, consisting of a broad flap on each side of the mandible, in 
front reduced to a narrow rim, the surface of the lip nearly smooth, with- 
out papillm. Nostrils large. Snborbital bones narrow, but rather 
broader than in Gatostomns. Preorbital unusually large. Mucous chan- 
nels moderately developed. Eoiitanelle very large. Isthmus rather 
narrow Pharyngeal bones weaker than usual in Catostomus, the teeth 
generally smaller. Body rather slender, tapering pretty regularly from 
the shoulders to the tail, but little compressed. Caudal peduncle rather 
stout. Pius moderate ; the dorsal rays about 12 ; the anal 7. Pectorals 
rather long, not quite reaching ventrals ; ventrals reaching vent ; anal 
fin high, reaching caudal; caudal fin rather long, its lobes equal. 
Scales moderate, large on the caudal peduncle, much smaller and 
crowded anteriorly, G0-G5 in the lateral line, about 18 in a transverse 
series from dorsal to ventrals. Sexual peculiarities unknown. Colora- 
tion usual. Air-bladder in two parts. Size moderate or rather large, 
to yawn.) 
