56 Bulletin 6 56 



Explanation of Plate i. 



(I) 



Page. 



Fig. I. Bellerophon ithacensis n. sp. , X2 39, 39. 



Dorsal view. 



2. Belle7'ophon ithacensis n. sp., X2 39, 39. 



Showing part of peristome. 



3. AviculopeHeti lautus var. ithacensis n. var. , x2.. 45, 45. 



Left valve. 



