PLATE XXXVI. 
MODIOMORPHA CONCEA'TIUCA. 
Page '275. 
See Plates 34, 35. 
Pig's. 1-12. Showing the variety of form, size and surface markings characteristic of the species. 
Hamilton group. Shores of Cayuga, Seneca, Canandaigua lakes and Pratt's falls, N. Y. 
Fig. 13. A cardinal view showing the ligamental area and ligament. 
Fig. 14. A partial cast of the interior showing the anterior muscular scar and pallial line. 
Hamilton group. Cumberland, Md. 
Fig. 15. The cast of the interior of a left valve showing muscular scars, pallial line, and the striated hinge 
area of the opposite valve. 
Fig-. 16. The interior of the left valve, partially obtained by a g-utta-percha impression, showing the strong 
tooth and the callosity below, with muscular scar and pallial line. 
Hamilton group. Cnmben-land, Md. 
Fig-. 17. A cast of the left valve showing the anterior muscular scar, the cavity of the tooth and the impres¬ 
sion of the striated ligamental area. 
Fig-. 18. A gutta-percha impression from the preceding, showing more clearly the characters of the interior. 
Hamilton group. Schoharie Co., N. Y. 
Modiomorpha cymbula. 
Page 282. 
Fig. 19. A cast of the interior of a left valve showing the muscular scars and pallial line. 
Fig. 20. A gutta-percha impression from the preceding. 
Hamilton group. .East Worcester, JY. Y. 
Modiomorpha arcuata. 
Page 281. 
Fig. 21. A partial cast of the interior, preserving some of the surface markings and showing the anterior 
muscular scar. 
Hamilton group. Schoharie Co., JY. Y. 
