CHAP. XII 



BERMUDA 



271 



14. Pupa jamaicensis. (C. B. Adams)... Jamaica. 



15. ,, rupicola. (Say.) N. America. 



16. Pupoides marginatus. (Say.) ... N.America. 



17. Ennea bicolor. (Hutton) East Indies. Introdiiced. 



18. I* (ECiLOZO'N ITES bermudensis. (Pfr.) A peculiar genus. 



19. nelsoni. (Bland) ... A sub fossil species. 



20. reinianus. (Pfr.)... 



21. , , circmn firmatus. ( R edf. ) 



22. Limax flavus. (L. ) I'robably introduced. 



23. Agriolinias lavis. (Miill.) ... ... 



24. Amalia gagates. (Drap.) ,, 



25. Succinea barbadensis. (Guild.) ... West Indies. (This includes the 



three species of Succinea in 

 former list. ) 



26. Veronicella schivelyse. (Pils. ) 



27. Onchidium floridanum. (Dall. ) ... Florida. 



28. Helicina convexa. (Pfr.) Peculiar species. 



The above enumeration shows that six species are now 

 held to be certainly peculiar to Bermuda, while four of 

 them belong to a peculiar genus. If we deduct ten of the 

 total number of species as having been introduced by 

 human agency, bringing the number of endemic species to 

 eighteen, we see that one-third of the whole have been so 

 modified as to be classed as peculiar species, while almost 

 all the other productions of the islands are identical with 

 those of the nearest lands. This corresponds, however, 

 with what occurs generally in islands at a considerable 

 distance from continents. In the Azores only one land- 

 bird is peculiar out of eighteen resident species; the 

 beetles show about one -eighth of the probably non- 

 introduced species as peculiar; the plants about one- 

 twentieth; while the land-shells have about half the 

 species peculiar. This difference is well explained by 

 the much greater difficulty of transmission over wide 

 seas, in the case of land-shells, than of any other ter- 

 restrial organisms. It thus happens that when a species 

 has once been conveyed it may remain isolated for un- 

 known ages, and has time to become modified by local 

 conditions unchecked by the introduction of other in- 

 dividuals of the original type. 



Flora of Bermuda. — Unfortunately no good account of 

 the plants of these islands has yet been published. Mr. 

 Jones, in his paper " On the Vegetation of the Bermudas " 



