[41] 



in St. Thomas and St. Jolin. Macroceramus {M. microdon, Pfr.) 

 inhabits Porto Eico, St. Thomas, St. John and Tortola, and M. 

 signatus^ Guild., Tortola and Anguilla, the latter on the St. 

 Martin bank. Strophia occnrs in Porto Eico, St. Croix (sub- 

 fossil), Anegada and subfossil remains onlj of a species on 

 Sombrero. Megalomastoma, Alcadia, Macroceramus, excluding 

 Pineria, treated as subgenus of it bj H. and A. Adams, 

 and Strophia, S. uva, L., of Curacao alone excepted, are not 

 represented in the Gruadeloupe subprovince.* 



Helix n'Aalnlis, Shuttl., is found in St. Thomas (subfossil), 

 St. John, Tortola and Anegada of the Virgin bank, and in St. 

 Bartholome\v of the St. Martin bank, but not in the Guade- 

 loupe subprovince. 



Dentellaria (subgenus of Helix), of which H. nux denticu- 

 lata, Chem., and H.formosa, Per., are types, is especially char- 

 acteristic of the Guadeloupe subprovince. It is represented 

 in Barbuda and Antigaa by H.formosa, in St. Kitts by H. Jo- 

 sephinae. Per., subfossilf), and occurs also in Guadeloupe, Do- 

 minica, Martinique, Barbados, &c., but not in the Porto Eico 

 subprovince. H. castrensis, Pfr., of Porto Eico, placed by Al- 

 bers in Dentellaria, and by Pfeiffer with species of that type, 

 is a questionable exception, — it appears to me to belong to the 

 same group as H. notabilis, and H lima, Per., — of the latter, 

 indeed, I have considered it a variety. 



The species common to the Porto Eico and Guadeloupe sub- 

 provinces, of which a list is annexed, are few, and of a char- 

 acter, their general distribution also considered, favorable to 

 my views as to the separation of the two faunas. 



(Those marked ^ occur also in one or more of the other sub- 

 provinces, ^^ also in ISTorth America, f also in South America.) 



HeUc ina fa^ciata, 



Lam. 



''^^ Helix vortex, 



Pfr. 



f^ Balimulus exilis, 



Gmel. 



t ^' elongatus, 



Bolt. 



t " fralerculus. 



Per. 



Pineria Viequensis, 



Pfr. 



Leptinaria Antillarum^ 



Shuttl. 



^ Stenogyra Goodalli^ 



Mil. 



Y^ " octona, 



Chem. 



* " octonoides, 



C. B. Ad. 



*- " suhula, 



Pfr. 



* I have already noticed that Megalomastoma and Strophia do not occur 

 in Jamaica, the most southerly of the lai-ger islands, and that Macroceramus 

 is there represented by M. Gossei, Pfr , only, — a species found also in Cuba 

 and Florida. 



t The occurrence in St. Croix, St. Thomas, Sombrero and St. Kitts, of 

 subfossil, or at least of species not now living on those islands, is a subject 

 of much geological interest. 



