416 A. HYATT — TRIAS AND JURA IN THE WESTERN STATES. 



g.-i^t- ' ^Daonella, sp. (?) 



This seems to differ from bochiformis only in outline. The umbones 

 are nearer the anterior end and the dorso-ventral diameter at the um- 

 bones is markedly longer than that near the posterior end. 



Daonella cardinoides, n. s. 



The valve of this shell often has an outline like some species of Car- 

 dinia and the longitudinal striae are correspondingly curved toward the 

 anterior and posterior ends ; otherwise it is similar to D. bochiformis. 

 A specimen of this species was found associated with the cephalopods 

 of the Ammonites bed of Sailors canyon, but the bulk of the specimens 

 were found in the bed below this. 



In company with the species of Daonella there are several specimens 

 of other species of Pelecypoda, but none of them sufficiently well pre- 

 served to be of any value for the determination of age. Some of these 

 last are also associated with the Ammonitinse. 



Hemientolium, (?) sp. (?) 

 Loc, Sailors canyon. 



Several impressions and molds of single valves represent w^hat I have 

 doubtfully referred to the genus Hemientolium. These are very small 

 shells having heavy concentric folds at irregular intervals like those of 

 an ostrean. The form is aviculoid with apparently straight hinge, as is 

 often the case in poorly preserved specimens of Hemientolium. There 

 is, however, in one specimen an appendage that appears to be an ante- 

 rior wing extending dorsally beyond the#hinge line, and in several others 

 the lines of growth and the irregular aspect of the same part confirms 

 this impression. The resemblance to H. daytonensis is not quite close 

 enough to make one sure of identity and I prefer to leave both genus 

 and species uncertain. Some of them are associated in the same slab 

 with a fragment of Ammonites, showing that they came from the lower 

 part of the Ammonite bed south of Sterretts. 



Panopea (?), sp. (?) 

 Loc, Sailors canyon. 



A crushed imperfect cast of a right valve has a resemblance to the 

 species described by Gabb as Panopea (?) remondi from Sonora,* but the 

 beak is perhaps nearer the center. There are heavy concentric folds on 

 this cast, but these are evidently largely due to pressure, and between 



* Geol. California, Pal. I, p. 23, pi. 5. 



