464 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
13. Catostomus ardens, sp. noy. 
(? Catostomus quzmaniensis Cope & Yarrow; not of Girard.) 
A large, thick-lipped species, allied to-C. macrochilus, &c. 
Body rather elongate, subfusiform, little compressed, the back broad 
and somewhat elevated. Head conical, broad and convex above, the 
front regularly sloping from the nape to the snout. Mouth entirely 
inferior, the mandible quite horizontal, the premaxillaries scarcely raised 
above the level of the base of the mandible. Upper lip very wide, full, 
pendant, with about eight rows of coarse, irregular papille, of which 
the second and third rows from the inside are much larger than the 
others; upper lip continuous with the lower at the angle of the mouth, 
the lower lip cut to the base in the middle by a deep, abrupt incision 
Front of eye midway in head. Hye very small, 7 in head, 34 in the 
convex interorbital space. Isthmus broad, half broader than the eye. 
Fontanelle large, as in the other species noticed in this paper. Scales 
crowded anteriorly, 9-65-9. Breast with evident imbedded scales. Dor- 
sal fin inserted a little behind the middle of the body, long and low, 
its anterior rays but three-fourths the length of the base of the fin, 14 
the length of the last rays; the free edge of the fin straight. Caudal 
fin short and broad, about equally forked, its upper lobe two-thirds the 
length of the head. Pectorals short and broad, their length three- 
fourths that of the head. Ventrals short, not quite reaching vent. 
Anal very high, reaching caudal. Dorsal rays 13; anal 7. Length of 
head 33 in body to base of caudal; greatest depth 44. Teeth essen- 
tially as in the others. ‘ 
Color blackish above, blotched with darker, the whole back and sides 
obscurely spotted; belly white; a narrow, bright, rosy, lateral band on 
the anterior part of the body, overlying the blackish; fins mostly dusky 
mottled; top and sides of head rendered dusky by the presence of many 
dark specks. : 
This species is described from a large adult male nearly 18 inches in 
length, besides which we have a single young specimen. 
There is another specimen in the collection, a large male fish 18 
inches long, which agrees entirely with the type of C. ardens, with the 
following exceptions: The lower lip is wider, with less conspicuous, 
coarse, irregular papillz, in 8 to 10 rows; the upper lip with two rows 
of large papillae and several series of small ones. The caudal fin is 
much larger, the upper lobe three-fourths the length of the head, the 
lower broader than the upper; the pectoral fin is very long, but little 
shorter than head; and the ventrals reach the vent. The dorsal has 12 
rays, and is long and low, as in C. ardens. The scales on the breast are 
almost obsolete. The isthmus shows a structure very different from 
that of any other Catostomoid fish known. The gill membranes are 
partly free posteriorly, their free margins forming a broad fold across 
the narrow isthmus, as in the genus Cottus. This structure appears 
normal, and is not the result of injury. If it be permanent, this form 
should probably constitute a distinct genus; if not, it may not be sepa- 
