CHAP. XTI 



BERMUDA 



271 



12. Helix pulchella. (Miill.) 



13. „ ventricosa. (Drap. ) ... 



14. Bulimulus nitidulus. (Pfr.) 



15. Stenogyra octona. (Ch.) ... 



16. Stenogyra decollata (Linn.) 



17. Coecilianella acicula. (Miill.) 



18. Pupa pellucida. (Pfr.) 



19. ,, Barbadensis, (Pfr.) ... 



20. ., Jamaicensis. (C B. Ad.) 



21. Helicina convexa. (Pfr.) 



. . . Europe ; very close to H. minuta 



(Say) of the United States. 



Introduced into Bermuda (?) 

 . . . Azores, Canary Islands, and South 



Europe. 

 ... Cuba, Haiti, &c. 

 ... West Indies and South America. 

 ... A South European species. 



Introduced. 

 ... Florida, New Jersey, and Europe. 

 ... "West Indies, and Yucatan. 

 ... Barbadoes (?) 

 ... Jamaica. 

 ... Barbuda.^ 



Mr. Bland indicates only four species as certainly peculiar 

 to Bermuda, and another sub-fossil species ; while one or 

 two of the remainder are indicated as doubtfully identical 

 with those of other countries. We have thus about one- 

 fifth of the land-shells peculiar, while almost all the 

 other productions of the islands are identical with those of 

 the adjacent continent and islands. This corresponds, 

 however, with what occurs generally in islands at some 

 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. 



^ Mr. Theo. D. A. Cockerell informs me that there are two slugs in 

 Bermuda of which specimens exist in the British Museum, — AmaUagagates 

 Drap. common in Europe, and AgrioUmam campestris of the United States. 

 Both may therefore have been introduced by human agency. Also 

 Vaginulus Mordctc var. schivelyca which seems to be a variety of a Mexican 

 species ; perha]is imported. 



