MESOZOIC TIME — CRETACEOUS. 



buO 



rig. 1365. The shells are in great profusion in many localities, and are often 

 associated with Belemnites appressus. Fig. 1366 is from a small shell from 



1361 a 



isei 



1360 



1363 



1362 



Lamellibeanchs. — Fig. 1859, G-ryphsea Pitcheri of Morton; 1860, Exogyra arietina ; 1361, Radiolites Texanus, 

 ■without upper valve (x ^); 1361 a, the lid-like upper valve ; 1362, Eequienia Texana. Gastropod. — Fig. 

 1363, Xerinea Texana. AU from Eoemer. 



1364-1366. 



1364 



1365 



1366 



MoLxusK. — Figs. 1864-1866, Aucella Piochii. Gabb. 



Mt. Diablo, where they are rare. The shells fail entirely, or very nearly so, 

 of the radiating striae which characterize the Jurassic Aucella of Mariposa 

 (page 759). 



