PLATE 3. 



Page. 



Fig. 1. Inoceramtjs gilberti 285 



a. Right valve ; test removed. 



b. Front view of the same. 



c. Left valve of another shell. All natural size. 



Fig. 2. Oyrena securis 289 



a. Right valve. 



b. Dorsal view of shell. 



•c. Front view of the same. Natural size. 



Fig. 3. Pteria parkensis 279 



a. Side view of internal cast of right valve. Natural size. 



Fig. 4 CoRBULA nematophora 290 



a. Mr. Meek's type, right valve, natural size. 



b. Right valve of an example identified by Mr. Meek, from Coal- 



ville, Utah. Natural size. 



c. Interior view of the same, showing the hinge. 



d. Front view of the same. 



Fig. 5. Admetopsis gregaria 318 



a. Apertural view of a specimen from near Cedar City, Utah; 

 identified by Mr. Meek ; enlarged one and a half diameters. 



