THE NAUTILUS. 3 



by the Distomata, etc., shell-material is deposited there, and 

 the filled-up distal end of the shell becomes dead and liable to 

 abrasion by mechanical, chemical or organic external agencies. 

 Blanfordia has been associated with the Truncatellidse by 

 Fischer and Tryon. The first one I saw was referred to the 

 genus Pomatiopsis (Amnicolidse), on account of the dentition, 

 which I described in Nautilus for May, 1900, p. 12. Two 

 years later I recognized that my species was a Blanfordia (cf. 

 Proc. A. N. S. Phila., 1902, pp. 26, 27); and I retained the 



Figs. 1, la, Blanfordia japonica. 

 3, 3a, B. SIMPLEX. 



2, 2a, B. NOSOPHORA. 



4. B. BENSONI. 



genus distinct from Pomatiopsis because of small differences in 

 the animal as described by Dr. Arthur Adams. The dentition 

 is, however, that of Poviatiopsis, which is rather characteristic 

 from the small number of denticles on the two outer teeth — 

 nearly all other Amnicolida having very numerous denticles on 

 these teeth. My removal of Blnvfordia from the Truncatellidse 

 and its approximation to Pmiaiiopsis was, I believe, justified. 



The type of Blanfordia is B. japonica. If the genus be 

 thought identical with Pomaiiopsis, the name may be retained 

 for the varicose species, in a subgeneric sense. 



P. S. — Since the above was written, I have received (April 

 16) a paper "Observations on the Spread of Asiatic Schisto- 

 somatosis," by Dr. R. T. Leiper and Surgeon E. K. Atkinson, 



