1888.] NATURAL SCIENCES OF PHILADELPHIA. 285 



ON THE HELICOID LAND MOLLUSCS OF BERMUDA. 

 BY H. A. PILSBRY. 



Tlirougli the courtesy of Professor Angelo Heili)rin I have been 

 enabled to study the Bermudan hind shells, collected by the party 

 conducted 1)y him during the past summer. Among them were ex- 

 amples of all the Helicoid species which have been reported by pi-e- 

 vious observers from the island, some containing the living animal. 

 The species, with the exception of a number of artificially intro- 

 duced European shells, are mostly forms well-known from various 

 West Indian localities ; such as Helix cereolus var. microdonta Desh., 

 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: H. ber- 

 mudensis Pfr., H. nelsoni Bid., H. reiuiana Pfr., H. circumfirmata 

 Redf, H. discrepant Pfr. As to the systematic position of these 

 forms there has been considerable difference of opinion among au- 

 thors ; the first, H. benniidends, has been ])laced in Caracolushj 

 Von Martens, in Hyalina by Clessiii. in Zouites by Bland ; H. rein- 

 laiia has been considereil a J^afuia by Pfeiffer, Clessin, Tryon and 

 Fischer ; and H. circumjiyinutu and diserepans have been placed in 

 Micvophysa by Von Martens and Binney, in Hyalomgda by Cles- 

 sin^ Tryon and others. 



Thus it will be seen that these s})ecies have been distiibiited into 

 several genera in two distinct families. Upon examining the soft 

 parts, however, I find that all have essentially the same organization 

 and without doul)t l)elong to the same genus. 



Dr. (). Boettger proposed in 1884, for the Lower Miocene fossil 

 Helix imhricata Braun, and the H.- bermudensis Pfr. the name of 

 Paicilozouites. lie gave no diagnosis of the new group, but assigned 

 it a position between the typical pahearctic Zouites and the American 

 groups Zonyalina and Moreletia, a position which the anatomical 

 characters prove to be erronetnis.' 



1 " * * * Endlich sei noch einer nahen Verwandten der Hoclieim- 

 er muermiocaner //f/ix ///il>//i-a/a Al. Biaun gedacht, die Saiidberger bekanntlich 

 zu Trochoinorpha [Discus) geslellt hat. Ich gebe die Aehnlichkeit zu ; aber zur 

 Section Videna H. u A. Adams, Discus Alb., mochte ich die betreftende fossile Art 

 nur ungern stellen, da alle mir bekannten lebenden Arten dieser Gruppe zum min- 

 dester einer verdichter basalrand, der oft recht erheblich Helix-artig umgeschlagen 



