1883.] NATURAL SCIENCES OF PHILADELPHIA. 149 



Chasmistes cajus sp. nov. 



I procured but one specimen of this fish from Pyramid Lake, 

 where it is difficult to obtain. The size is large ; the specimen I 

 procured measured eighteen inches in length. The head is wide and 

 flat, the width of the interorbital space being more than half the 

 length. The upper lip is very thin ; the lower lip is represented 

 b}' folds on each side, which do not connect round the symphysis. 

 Scales 13-65-11. Dorsal rays 12; anal I. 8. The eye enters the 

 length of the head 8"5 times, and the interorbital width 4*5 times. 

 The swim-bladder has but two cells. The colors are pale olive. 



The pharyngeal teeth of this species are much like those of the 

 G. liorus in their triangular section ; they are, nevertheless, of 

 delicate construction. The head of this species is relatively 

 larger and wider than in any of the others, which gives it a heavy 

 and clumsj^ appearance. 



This fish is said by the fishermen to inhabit the deepest water, 

 and to be seen in numbers only at the time of breeding. Its 

 habits in this respect agree with what is said of the C. luxatus of 

 the Klamath Lake. The Indian name of the Chasmistes cujus 

 is "Couia." 



Chasmistes brevirostris Cope. American Na'uralist, 1879, p. 785. Jordan, Fishes 

 N. Amer., p. 132, 1883. 



This fish does not exceed 14 to 16 inches in length, and has a 

 differently formed head and muzzle from the C. luxatus. They are 

 shorter, especially the muzzle, and the latter is without the hump 

 produced hy the protuberant premaxillar}- spines. Parietal fon- 

 tanelle small. The lower lip-fold is only present at the sides of 

 the mandible. Both lips are smooth. Eye round, its diameter 

 entering the length of the head six and two-thirds times, of which 

 three times enters the muzzle. Interorbital region flat, its width 

 entering the length of the head two and one-eighth times. Body 

 nearlj'^ cylindric. Scales 12-t4-ll; radii D. 11, A. 9. Color 

 dusky above, silvery below ; fins colorless. This fish is abundant 

 '"in Klamath Lake, but I was informed by a Klamath chief, that it 

 does not ascend Williamson's River in spring with the C. luxatus 

 and Catostomus labiatus. Klamath name, "Xodptu." 



Chasmistes luxatus Cope, American Naturalist, 1879, p. 785. Jordan, 1, c, p. 132. 



Form elongate ; head long, flat above, and with a large fontanelle. 

 Mouth terminal, the spines of the premaxillary bones projecting 

 so as to form a hump on the top of the snout. Lower lip a very 



