PLATE LXXV. 



JURASSIC SPECIES. 



Paire. 



Thraeia weecli n. sp 627 



Fig. 1. Right valve of usual size ami outline. 



2. Left valve of a shorter form. 



3. Left valve of an elongate specimen. 



Neritina wyomingensis n. sp 629 



Figs. 4, 5. Opposite views of the type; enlarged 3 diameters. 



CRETACEOUS SPECIES. 



Goniobasist pealei n. sp 632 



Fig. 6. An average specimen ; enlarged 2 diameters. 

 Goviobasisl increbesceiis n. sp 63i 



Fig. 7. A medium-sized specimen; enlarged 2 diameters. 

 Amnieola ? cretacea n. sp 633 



Fig. 8. An average specimen ; enlarged 2 diameters. 

 Inoceramus acuteplicatus n.sp 634 



Fig. 9. A small left valve supposed to belong to this species. 



10. A small right valve. (See PL LXXVI for additional figure.) 



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