of the Island of St. Thomas, W. I. 73 



34. Amnicola crystallina* (Pfr.). 



" var. /3. coronata (Paludestrina 

 coronata Pfr.). Etiam in Portorico. 



35. Neritina virginea (Linn.). Habitat etiam in Portorico. 



36. Neritina meleagris Lam. " " " 



37. Neritina viridis Lam. " " " 



38. Melampus coniformis (Brug.). " " " 



39. Melampus monilis (Lam.). " M " 



40. Melampus nitens (Lam.). " " " 



41. Pedipes quadridens Pfr. " " " 



42. Odostomia (Tornatellina) CuBENSisf (Pfr.). Habitat 

 etiam in Portorico. 



* I cannot distinguish these as more than forms of the same species, as I find 

 every passage from the smooth to the aculeated shell. As the smooth form is 

 most abundant, I take it as the type of the species. Paludestrina Candeana Orb. 

 appears to be different — it is from Guadaloupe, and is probably the same as 

 Melania spinifera C. B. Ad., which differs from the Cuba and St. Thomas species 

 not only in greater breadth, but by scarcely any appearance of perforation or 

 rima. From Portorico I think I have one or two other species, but am not yet 

 clear how far differences in size, and greater or less acumination of the spire, are 

 characteristic in this difficult genus. The name Amnicola must be retained in 

 preference to Hydrobia Hartm., Paludinella Pfr., and Paludestrina Orb. r. j. s. 



f This is a litoral (marine) shell — it was collected by Blauner with species of 

 Rissoa, Scutella, &c, and sent with them marked marine. It will rank with 

 Truncatella, Auricula, and Pedipes, in its claim to being land or freshwater. It is 

 decidedly no Tornatellina, and I have no doubt of my supposition that it is an 

 Odostomia. The solidity of the shell, its glossy appearance, &c, are quite differ- 

 ent from the true Tornatellina. r. j. s. 



