H. A. Pilsbry — Air-hreathing MollusJcs of the Berinudas. 493 



From the data supplied by Prof. Verrill's expedition and that of 

 Prof. Heilprin it seems that Vallonia pulchella^ , CmclUoides acicula, 

 Agriolimax Icevis, and Physa acuta rest upon single records now 

 nearly twenty years old, and they may not have permanently colo- 

 nized ; but as none of them are conspicuous forms, and no special col- 

 lectors of land shells have sought for them, the merely negative 

 evidence is inconclusive. Probably all the others are well established 

 colonists. 



The abundance of European forms corresponds with the prepon- 

 derance of European shipping in former times. The Indian or East 

 Indian forms Avere probably brought with living plants for the 

 Botanical Garden ; while the single North American form, P. 

 appressa, may have had a similar advent. How the Physa found its 

 way to Bermuda is problematic, ° as the cistern in which it occurred 

 is one of the I'oofed rain-water catchment reservoirs commonly in 

 use in the islands. 



It is somewhat peculiar that Helix nemoralis, lactea, and aspersa 

 have not yet established themselves in Bermuda, as they are usually 

 among the first emigrants from the old country, like the slugs. 



' This species was recorded both by J. M. Jones, 1876, and by Bland, 1881, inde- 

 pendently, but as Jones and Bland were in correspondence at that time (see p. 508), it 

 is quite probable that it was collected only by Jones, who resided in the Bermudas 

 during many years in the winter and spring season and made large collections there. — 

 (A. E. V.) 



^ It may have been introduced with the cultivated water lilies. — (A. E. V.) See 

 note, p. 503. 



