122 NON-MAKLNE FOSSIL MOLLTJSCA. 



PLATE 21. LARAMIE. 



Cokbicola berthoudi White. (Page 32.) 



FlG. 1. Left valve of a large example, exterior view. 

 Fig. 2. Dorsal view of another example. 

 Fig. 3. Interior view of a left valve. 

 (All natural size ) 



Cokbicula AUGHEYI W. (Page 32.) 



Fig. 4. Exterior view of a right valve. 

 Fig. 5. Interior view of the same. 

 Fig. 6. Dorsal view of another example. 

 (All natural size.) 



% Corbicula umbonella Meek. (Page 32.) 



Fig. 7. Exterior view of a left valve. 



Fig. 8. Interior view of the same. 



Fig. 9. Dorsal view of another example. 



Fig. 10. Front view of the same. 



Corbicui^a (Leptesthes) macropistha W. (Page 31.) 



Fig. 11. Left side view of an adult example. 

 Fig. 12. Dorsal view of the same. 

 Fig. 13. Left side view of another example. 

 Fig. 14. Interior view of a left valve 



