52 G NON-MARINE FOSSIL MOLLUSCA. 



PLATE 20. LARAMIE. 

 CORBICULA (LEPTESTHES) FRACTA Meek. (Page 439.) 



FIG. 1. Copy of Mr. Meck's original figure. 



FIG. 2. Left side view of a robust example. 



FIG. 3. Dorsal view of tlio same. 



FlG. 4. Left side view of a young example. 



FIG. 5. Dorsal view of the same. 



FIG. 6. Left side view of a more elongate, partially cruslied example. 

 (All natural size.) 



CORBICULA CLEBURXI White. (Page 437.) 



FIG. 7 Left side view of an adult example. 

 FIG. 8. Right side view of a smaller example. 

 FIG. 9. Interior view of the same. 

 (All natural size.) 



CORBICULA SUBELLIPTICA Meek & llayden. (Page 437.) 



FIG. 10. Exterior view of a right valve; natural size. 

 FIG. 11. Interior view of the same. 



CORBICULA NEBRASCEXSIS M. & H. (Page 437.) 



FIG. 12. Exterior of a left valve; natural size. 

 FIG. 13. Interior view of the same. 



PISIDIUM SAGINATUM W. (Page 440.) 



FIG. 14. Lateral view, enlarged. 

 FIG. 15. Front view of the same. 



