142 



University of California Publications. 



[Geology 



dentalis by Agassiz. Cope states that the ethmoid of his fossil 

 specimens is half as long as wide. If that be so, they cannot be 

 referred to Catostomns snyderi, as in that species the length of 

 the ethmoid is from three-fourths to four-fifths of the width. 

 Possibly he compared his specimens with skulls of Chasmistes 

 (two species of which are found in Klamath Lake), in which the 

 length of the ethmoid is from two-fifths to three-fifths of the 

 width. In our cranium number one the anterior part is conspic- 

 uously convex transversely as well as in profile. There is no 

 frontal keel in front of the f ontanelle, and the fontanelle is rather 

 narrow as compared with other specimens. A sharp supratem- 

 poral keel is developed laterally and overhangs the temporal 

 fossa. In Catostomus snyderi the surface of the frontal rises 

 from the temporal fossa over a smooth, rounded, supratemporal 

 ridge to the superior surface, and the ridge is not developed lat- 

 erally as an overhanging crest. This may be named Chasmistes 

 oregonus, new species. 



Cranium number two differs from number one in being flatter 

 across the ethmoid and anterior frontal regions, in having a wider 

 f^ontanelle and a frontal keel developed. In the two latter char- 

 acters it resembles number three, though in general characters it 

 is evidently closer to number one. This species we leave unnamed 

 for the present. 



