1880.J NATURAL SCIENCES OF PHILADELPHIA. 237 



DESCRIPTION OF A NEW SPECIES OF CATOSTOMUS (CATOSTOMUS CYPHO) 

 FROM THE COLORADO RIVER. 



BY WM. N. LOCKINGTON. 



Catostomus cypho, sp. nov. 



D. 3, 14. A. 2, T. C. M-16-1-Y. P. 18. T. 10. L. lat. 79. 



Head conical ; snout long, much depressed ; dorsal outline 

 rising in a straight line to the occipital region, where commences 

 a prominent and considerably elevated liump, which attains its 

 greatest height at a distance from the occiput about equal to the 

 length of the snout, and thence descends to the origin of the 

 dorsal. 



Along the base of the dorsal fin the dorsal outline descends 

 rapidly to about the end of the second third of the total length of 

 the fish ; caudal peduncle extremely elongated, and widening 

 considerably' toward the caudal base. 



Abdominal outline almost straiglit to the origin of the anal, 

 thence diminishing to the caudal peduncle. 



Greatest depth, at anterior pectoral axil, contained not quite 

 4^ times ; head a little more than 4 times in tlie total length ; 

 snout a little more tlian 2|, eye between 8 and 9 times in the 

 length of the head ; length of top of head not quite 2^ times in 

 the distance (in a straight line) from the tip of the snout to the 

 dorsal ; inter-ocular width equal to the length of the snout ; 

 pectoral about 1^ in length of head ; caudal peduncle about 3| in 

 the greatest depth. 



Moutli rather wide, inferior. Lower lip small, in two distinct 

 ovoid lobes, covered with low, flat-topped papilla? ; the front of 

 the dentarj- bones covered by a well-developed, round-edged, horny 

 plate. Lower lip quite distinct from the upper ; the skin of the 

 cheeks forming an obliquely ascending crease, which does not, 

 however, cover the angle of the mouth. • 



Anterior nostril horizontally sub-elliptical ; posterior large, 

 vertical, crescentic, entirely covered by its anterior flap. 



Two distinct rows of pores on the top of the head ; connected 

 on the occiput with a series running behind and below the eye 

 almost to the tip of the snout. 



Phar3Migeals arcuate, with numerous teeth, regularly' diminish- 

 ing posteriorly. 



