364 



THE PRESENCE OF A DOUBLE WALL IN SOME SPECIES OF THE 

 DIAPHORA GROUP OF ENNEA. 



By Hugh C. Fulton. 



Read Uth June, 1907. 



Upon breaking open a specimen of Ennca {Diaphora) MoUe^idorfji, Hid., 

 in order to examine its internal structure, I found that from about the 

 fifth whorl from the apex down to about the eleventh there is a double 

 wall, thus reducing the size of the cavity occupied by the mollusc. 

 Of other species of this group examined by me the following have the 

 same structure : Emwa {Diaphora) plvidogyra, Molldif., and E. Morleti, 

 Hidalgo. 



'^(tfl 



I was unable to find this double wall in E. {I)iaplior(C) dicraspedia, 

 Molldff., Locardi, Hid., Quadrasi, Molldff., and tuba, Molldff.; in the 

 last-named species the earlier whorls are cut off from the latter ones 

 by a septum. 



Diaphora was created by Albers in 1850 for Cylindrelln Cmningiana, 

 Pfr., a species that does not appear to have been found again by recent 

 collectors. 



