150 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY III. 



Fins moderate, the dorsal rays about 12, the anal 7 : pectorals 

 rather loug, not quite reaching ventrals : veutrals reaching vent : anal 

 tin high, reaching caudal : caudal fin rather long, its lobes equal. 



Scales moderate, large on the caudal peduncle, much smaller and 

 crowded anteriorly, 60 to G5 in the lateral line, about 18 in a transverse 

 series from dorsal to ventrals. 



Sexual peculiarities unknown. 



Coloration usual. 



Air-bladder in two parts. 



Size moderate or rather large. 



The single species now included in this genus is known only from 

 Utah Lake. Its describers referred it to the genus Catostomus^ but 

 made no mention of its singular mouth and lips. The original type of 

 the species is in very bad condition, the mouth being shrunken and dis- 

 torted, and the bones of the head protruding through the skin, so that 

 the peculiarities of the species are hardly recognizable.* 



Genfric Characterizations. 



CHASMISTES Jordan, 1878. " This genus is distinguished from Catostomus by the 

 very large, terminal mouth, the lower jaw being very strong, oblique, its length about 

 one-third that of the head. The lips are little developed, and are very nearly smooth. 

 The type of the genus is C. fecundus Cope & Yarrow." (JORDAN, Bull. U. S. Geol. Sun: 

 Terr. vol. iv, No. 2, p. 417, 1878.) 



ANALYSIS OF SPECIES OF CHASMISTES. 



* Depth about 5 in length ; head 3| ; interorbital space broad, 2| in head ; eye 6 to 7 

 in head ; width of the open mouth 3^ in Lead. Dorsal 12. Anal 7. Scales 

 9-63-8. Color dusky above, pale below ; the scales of the back and sides pro- 

 fusely covered with dark punctulations FECUNDUS, 23. 



23. CHASMISTES FECUNDUS (Cope & YarroiD] Jordan. ' 



Sucker of Utah Lake. 

 1876 Catostomus fecundus COPE & YARROW, Wheeki's Expl. W. 100th Mer. v, Zool. 



678, pi. xxxii, f. 1, 1 a. 



Catostomus fecundus JORDAN & COPELAND, Check List, 156, 1876. 

 Chasmistes fecund us JORDAN, Bull. Hayden's Geol. Surv. Terr. vol. iv, No. 2, 417, 



1878. 



HABITAT. Utah Lake, Utah, where it is excessively abundant. Not yet noticed 

 elsewhere.. 



This singular species has been overlooked until quite lately. Dr. 

 Yarrow states that it " is abundant in Utah Lake, and is called Sucker 



* In fact, this specimen in its present condition looks tome more like Catostomus occi- 

 dentalis, but the figure published by Cope & Yarrow represents C. fecundus. Both 

 species occur in Utah Lake. 



