Professor Adams, the discoverer of this shell, thought proper 

 to refer it to the C. calyculata, of Europe. I have compared 

 specimens from Vermont with the C. calyculata from England, 

 Germany, and Switzerland, and truly striking as is the similarity, 

 I am inclined to believe our shell to be distinct; it is a little 

 more elongated, more compressed, and anteriorly more rounded. 



Compared to the C. pariumeia, it is much less inflated, the 

 beaks are smaller but more tumid, as also much smaller. It is 

 less inflated than the C. securis, and also a little more elongated. 

 Found plentifully in running brooks under stones. Mighels. 



15. Cyclas partumeia Say, Journ. Ac. Nat. Sci. ii. 380. 



Cabinet of the B. S. N. H. 



Cyclas cornea, var. Lamarck, vi. 268. 



Cyclas orhicularia Barratt. Linsley's Cat. of Con. Shells, Anier. 



Journ. xlviii ; De Kay, 223, pi. 25, f. 262. 

 Cyclas mirabilis Prime. Bost. S. N. H. Proc. iv. 157. 

 Cyclas coerulea Prime. Bost. S. N. H. Proc. iv. 161. 



Animal. Siphon light pink. 



Shell Vide Gould's Report, 73, fig. 54. 



Localities. Maine, Vermont, (Adams.) Massachusetts, 

 (Gould.) Connecticut, (Linsley.) New Jersey, (Richard.) Penn- 

 sylvania, (Say, Anthony.) Whitehall, N. Y. (Ingalls.) Ohio, 

 (Jay, Ingalls.) South Carolina, (Ravenel.) Georgia, (Haldeman.) 



The general resemblance of this shell to the C. cornea, of 

 Europe, is very close. Its size, color, and tumid form are the 

 same. But that species has the beaks much less elevated, is 

 broader from side to side, and the two ends are almost precisely 

 alike, without any angle or any widening behind. Our shell is 

 on the whole more delicate. The young and old differ both in 

 shape and color. The young are less tumid and larger, and 

 the disparity of the sides is much greater than in the adult. 

 They have, also, a light honey-yellow color, and green transpa- 

 rency. They would scarcely be recognized as the same species, 

 except by being found in company, and also by being actually 

 found within the adult shell. Gould's Report, 73, This species 

 is very common all through New England, and is generally 



