66 ANNUAL REPORT OF STATE GEOLOGIST. 



from the Lower Trias of Idaho, apparently belonging - to Astera- 

 cantlius, has been described by H. M. Evans 1 as a new species of 

 Cosmacanthus. This last-named species is the only ichthyodoru- 

 lite yet recorded from the American Trias, and the total absence 

 of Elasmobranch remains in the eastern area may be regarded, 

 so far as the evidence goes, as straightening our belief that these 

 sediments were deposited under brackish water conditions. 



One other western locality furnishing fossil fishes of sup- 

 posed Triassic age is worthy of brief mention in this connection. 

 During the years 1879 and 1882 a small collection of ichthyic 

 remains was obtained by Dr. C. D. Walcott, Director of the 

 United States Geological Survey, in the Kanab Valley, Utah, 

 and adjoining regions in Arizona. These remains, which have 

 recently been placed in the hands of the writer for investigation, 

 are extremely fragmentary, and do not premit of accurate specific 

 determinations. Of the few genera which are tolerably well 

 indicated, such as Pholidophorus and several Lepidotus-like 

 forms, it cannot be said that they evince anything in common 

 with the Triassic fauna of the eastern States. Some resemblance 

 is to be noted between the Kanab fish-fauna and that of Perledo, 

 near Lake Como, but the general aspect of the material collected 

 by Walcott is much more suggestive of Jurassic than of Triassic 

 relations. This might very well happen notwithstanding the 

 horizon be definitely proved by stratigraphic and other evidence 

 to be of Triassic age, as other instances of pioneer faunas and 

 overlapping types are not uncommon. It does not appear, however, 

 that the data thus far obtained warrants more than a plausible 

 supposition that the Kanab beds are of Triassic age, their reddish 

 color and relative position being consistent with what we should 

 expect of rocks of that horizon. Accepting the evidence furnished 

 by the fossil fishes at its full value, we shall have to regard the red 

 beds of Kanab Canon as belonging presumably to the Lias. 



1 Evans, H. M., A. New Cestraciont Spine from the Lower Triass'c of Idaho 

 Bull. Dept. Geol. Univ. of California, vol. iii. (1904), pp. 397-402, pi. xlvii. 



