PLATE 6. 



Page. 



Fig. 1. Gltcimeeis berthoudi 299 



a. Left-side view ; natural, size. 



h. Dorsal view of tlie same example. 



Fig. 2. Bahbatia coalvillensis 286 



a. Exterior view ; left valve ; natural size. 



&. Interior view, showing Mnge, the middle portion of "wMcli Ib 

 imperfect. Both are partial restorations. 



Fig. 3. Plicatula hydeotheca 279 



a. Natural cast in sandstone of the deeper valve ; natural size. 

 6. External view of the ujiper or flat valve. 



Fig. 4. Mactra"? HOLMEsn 295 



a. Eight valve ; natural size. 

 &. Left valve. 



c. Side view ; type-specimen. 

 Fig. 5, a and h ; represent probably the same species ; from near 

 Canon City, Colo. 



Fig. 6. Caryophyllia johannis 274 



a. Side view ; enlarged two diameters. 

 J. Calycular view of the same. 



Fig. 7. Caryophyllia? egekia 275 



a. Side view ; enlarged two diameters. 



6. Vertical view of another example, broken across just belo"W 

 the calyx. 



