100 CALIFORNIA ACADEMY OF SCIENCES. 



Anodonta decurtata Conrad, Amer. Jour, of Con- 

 chology, vol. vi, 187 1, p. 200, described and figured from 

 a cast said to be from Colorado. Plate xiv, figs. 5-8. 



The six specimens found differ considerably among 

 themselves, partly from compression, partly, it may 

 be, from sexual variation, so I have figured two 

 of the best for comparison, especially as his w^as 

 only a cast, and these have much of the shell. They 

 show a striking resemblance to Conrad's. No living 

 species seems to be so short, and I would have called 

 it a Unio, if I had not found the hinge well exposed. No 

 Unio is known now to be living near the west coast. The 

 specimens figured are of natural size. With them is one 

 specimen more elongated, and perhaps a form of A. niit- 

 taliana Lea, but too imperfect to decide upon. That 

 species is fossil in several other localities of apparently 

 as ancient date. See PL xiv, fig. 11. 



The Asphalto Lake Bed. 



About forty miles southeasterly from the Kettleman 

 bed, in Kern County, is a small fresh water deposit, also 

 found by Mr. Watts, in 1893. This is eighteen miles 

 northwest of Buena Vista Lake, and 1,100 feet above the 

 sea, or 800 above the lake, and seems to have been up- 

 lifted much more than the one described above, yet does 

 not furnish so many species and none of them are extinct. 

 It was perhaps entirely disconnected from the Tulare 

 lakes, and is now nearly surrounded by hills, while the 

 lake deposit of blackish marl has a dip of 80° northeast. 

 The species brought from there are : 



1. Anodonta nuttalUana Lea. 3. Phi/sa sp. 



2. Carinifex neivherryilueii. 4. Po7natiopsls intermedia Tvyon. 



Three good specimens of No. i do not differ much 

 from the variet}" californiensis now inhabiting southern 

 California. No. 2 is scarce, and only 3-whorled, this 



