112 



Figure 4. Ampullaria Brownii, Nobis. 



Habitat, River Amazon. 



Remarks. — Tliis ponderous Ampullaria was procured from Capt. Brown, of 

 Beverly, Massachusetts, who brought it from the above mentioned locality. It 

 bears some resemblance to the Ampullaria crassa. Swains, figured in Spix. tab. 

 Y. f. 1. It may, however, be only a variety. 



Pigure 5. Ampullaiua Storeria, Nobis. 



Habitat, River Amazon. 



Remarks. — This is also one of the rarities brought home by Capt. Brown ; 

 and it is at his suggestion that I have named it after a very able and zealous 

 Naturalist. D. Humphrey's Storer, M. D. of Boston. 



Figure 6, 7. Helix Planorbis, Nobis. 



Habitat, Island of Togobo, Gulf of Guyaquil. 



Remarks. — This beautiful shell was found by Capt. Sloat, U. S. N. It is 

 owing to the generosity of his Son, in whose cabinet it was, that I am enabled 

 to add this unique shell to my collection. It was the only one obtained, al- 

 though some time was spent in searching for another. The marking on the 

 upper surface is very similar to that of the Helix pelli.s-serpentis. 



Figure 8, 9. Paludina scalaris, Nobis. 



Habitat, Everglades of Florida. 



Remarks. — This shell is white, semi-transparent, and very fragile; the su- 

 tures of the whorls are very angular, and of the same character with the Ampul- 

 laria scalaris, D'Orbigny. It was presented to me by Count Castelneau, whose 

 researches in this country will, without doubt, add much interesting matter to 

 our knowledge of Natural History. 



Figure 10, 11. L\mn.«;a gracilis, Nobis. 



Habitat, Essex Co. New- York. 



Remarks. — I am indebted to Professor Benedict, of Burlington, Vermont, lor 

 two specimens of this very slender and fragile LymnEea. 



