ZOOLOGY. MOLLUSCA. 191 



ON THE HELICOID LAND MOLLUSKS OF BERMUDA. 



BY 

 H. A. PILSBRY. 



Through the courtesy of Professor Angelo Heilprin I have 

 been enabled to study the Bermudian land shells collected by 

 the party conducted by him during the past summer. Among 

 them were examples of all the helicoid species which have 

 been reported by previous observers from the island, some con- 

 taining the living animal. The species, with the exception of 

 a number of artificially introduced European shells, are 

 mostly forms well known from various West Indian localities, 

 such as Helix cereolus var. microdonta Desb., H. vortex Pfr. and 

 others ; but besides these, there are a number of shells peculiar 

 to Bermuda, and these last have furnished material for the 

 following notes. 



The helicoid species confined to Bermuda are as follows : //. 

 Eermudensis Pfr., H. Nelsoni Bid., //. Reiniana Pfr., H. circum- 

 firmata Redf., H. discrepans Pfr. As to the systematic position 

 of these forms there has been considerable difference of opinion 

 among authors; the first, //. Bermudensis. has been placed in 

 Camcolus by Von Martens, in Hyalina by Clessin, in Zonites by 

 Bland ; H. Reiniana has been considered a Patula by Pfeiffer, 

 Clessin, Tryon and Fischer; and //. circumfirmata and dis- 

 crepans have been placed in Microphysa by Von Martens and 

 Binney, in Ilyalosagda by Clessin, Tryon and others. 



Thus it will be seen that these species have been distributed 

 into several genera in two distinct families. Upon examining 

 the soft parts, however, I find that all have essentially the 

 same organization and without doubt belong to the same 

 genus. 



Dr. 0. Boettger proposed in 1884, for the lower Miocene 

 fossil Helix imbricata Braun, and the H. Bermudensis Pfr., the 

 name of PcecMozonites. He gave no diagnosis of the new 

 group, but assigned it a position betwen the typical Palrearctic 



