PLATE LXXVI. 



Pkothykis planulata. 



Page teo. 

 See Plate 94. 

 Vig. 1. The left side of a specimen enlarged to two diametei's. 



Hamilton group. Outlet of Crooked lake, N. Y. 



Prothykis lanceolata. 



Page 460. 

 KgB. 2-8. A series of specimens showing the prevailing forms in this species. Fig. 8 is enlarged to two 

 diametei's. 



Hamilton group. Eastern and central New York. 



MODIELLA PYGM^A. 

 Page 614. 

 Figs. 9-20. A series of valves illustrating the principal varieties of form and surface characters of this 

 species. Figures enlai-ged to two diametei-a. 

 Hamilton g^roup. Central New York. 



Tellinopsis subemaeginata. 



Page 464. 

 Figs. 21-31. A series of valves showing variations in size and form. 

 Hamilton group. Eastern and central New York. 



