of the Island of St. Thomas, W. I. 71 



18. (17.) Pupa servilis* Gould. Specimina authentica cl. 

 auctoris nondum vidi. P. pellucida et marginalia Pfr. mihi etiam 

 ignote. P. Riisei Pfr. mihi hucusque nee ex St. Thomas, nee 

 ex Portorico obvia. P. servilis Gould habitat etiam in Porto- 

 rico. 



19. (6.) Macroceramus microdon (Pfr.). Varietas major, 

 anfr. planioribus, &c., habitat in Portorico, sed rarior. 



20. (5.) Cylindrella pallida (Guild.). Forma major, ha- 

 bitat etiam in Portorico. 



21. (18.) Succinea approximans Shuttl. n. sp. ? Habitat 

 etiam in Portorico. Differt ab S. Sagra Orb. spira multo magis 

 elevata, — sed etiam distincta a S.fulgens Lea. 



22. (1.) Cyclostoma (Megalomastoma) Antillarum 

 Sowb. — etiam in Portorico. 



23. (2.) Cyclostoma (Chondropoma) Newcombianum C. 

 B.Ad. 



24. (3.) Helicina subfusca Mke. Annon species irnma- 

 tura ?f 



individuals from Florida, and sent to me magnified outlines of both, taken with 

 a camera lucida. He remarks : " The number of ribs is the same, though this 

 number varies in different specimens, as does the size of the ribs." t. b. 



* I lately submitted specimens from St. Thomas to Dr. A. A. Gould, who found 

 them " to correspond in all respects" with his shell. t. b. 



\ I cannot distinguish young unfinished specimens of H. striata Lam. from 

 these. May it not be the H. striata transported from Portorico, and never at- 

 taining full size and perfect state, as is the case with B. decollatas in the Canaries ? 



R. J. s. 



The physical circumstances under which the animals live in the two nearly 

 adjacent islands are, I must think, the same, and I cannot, therefore, adopt the 

 suggestion of Mr. Shuttleworth. t. b. 



