Catalogue of Terrestrial and Fluvialile Shells. 



XI. — Catalogue of the Terrestrial and Fluviattle Shells of St. 

 Thomas, West Indies, by E. J. Shuttle worth, of Berne, Swit- 

 zerland, Corresponding Member. 



Communicated by T. Bland.* Read Feb. 6, 1854. 



1. (21.) Helix vortex Pfr. Habitat etiam in Portorico. 



2. (23.) Helix suBAQUiLAf Shuttl. n. sp. Differt ab H. 

 Boothiana Pfr. et H. peraffinis C.B.Ad., umbilico angustiore, 

 spira depressiore, et colore ssepe pallide corneo vel infumato. 

 An forsan H. spreta C. B. Ad. species mihi ignota. Habitat 

 copiosissime in Portorico. 



3. (22.) Helix euclasta Shuttl. n. sp. Differt ab H.fragi- 

 lis Pfr., cui maxime affinis, costulis confertioribus, minus pro- 



* In October, 1852, with the assistance of the late Professor C. B. Adams, I 

 prepared a " Catalogue of the Terrestrial Shells of St. Thomas, W. I.," which was 

 published in Tart XI. of his " Contributions to Conchology." At the same period 

 I learned from Professor Adams that Mr. Shuttleworth contemplated a publica- 

 tion on the Terrestrial and Fluviatile Shells of the West Indies, and was engaged 

 on those of St. Thomas, in which island bis collector, the late Mr. Blauner, had 

 been lately employed. I accordingly sent to Mr. S. specimens of all the species 

 which I had myself collected in that island, in the spring of 1852, and requested 

 him, after examination of Mr. Blauner's shells, to favor me with his observations, 

 as I much desired to have a correct catalogue of the species. 



Mr. S. has very kindly complied with my wish, by transmitting the accompany 

 ing notes; — at the date of them (20th December, 1853), he had not published his 

 diagnoses of the new species, as he waited to ascertain the result of the labors of 

 Dr. Pfeiffer, who had received at least some of them through Mr. II. Cuming. 

 The numbers within brackets correspond with the numbers of the species in my 

 catalogue in the "Contributions to Conchology." t. b. 



\ Poey believes this to be H. Boothiana Pfr. He remarks that the narrower 

 umbilicus, and more depressed spire, are noticeable in some individuals only, and 

 that the color depends on the degree of freshness of the shells. I have compared 

 this shell with II. spreta C. B. Ad., and also with H. Boothiana Pfr., sent to me 

 by Poey from Cuba, and am of opinion that it is distinct from each. t. b. 



