PLATE 75. 



Fig. 1. 690. 10. Tellinomya? EQuiLATERA. ( Pag, 330.) 



1 a, b. Similar views of two specimens, showing a slight difference in form, probably due to pressure. 

 1 c. Cardinal view of fig 1 a. 



1 d. View of the posterior slope, showing the groove in each valve. 



Fig. 2. 691. 11. AvicuLA? . (Pag. 831.) 



2 a, b, c. Right and left valve, and profile view of the specimen. 



Fig. 3. 692. 12. Avicula subrecta. (Pag. 331.) 



Left valve of .4. subrectj. 



Fig. 4, 5. 693. 13. Avicula securiformis. ( Pag. 331.) 



4. Cast of the left valve. 5 a. The interior of the left valve of a young shell. 



5 b. The interior of the left valve of a full grown individual. 



Fig. 6. 694. 14. Avicula lim^formis. ( Pag. 332.) 



6 a. Cast of the interior of the right valve, in which the plications are quite distinct and angular. 



6 b. Interior of tlie right valve of another specimen, in which the spaces between the plications are nearly flat. 

 6 c. Portion enlai-ged. 



