51 



L. desidii'Sa. L. philadelphica. L. acuta. 



L. ohrussa. 



Fig. 73 gives, at one view, the forms which I have 

 referred to the synonymy of this species. 



Fig. 14 represents the European representative of 

 L. desidiosa. It is copied from Moquin-Tandou's 

 fiirure of L. truncatula. 



L. fusiformis. 



Fig. 74. 



Fig. 75. 



L.iiun£ea eniarginata, Say.— Shell rather thin, translucent ; 

 volutions four, very convex ; body whirl large ; suture deeply impressed, 

 spire somewhat eroded; mouth two-thirds of the length of 

 the shell. Length nearly four-fifths of an inch ; of the mouth, 

 half an inch. 



Inhabits lakes of Maine. 



This species was discovered by Mr. Aaron Stone. It is a 

 rather larger and considerably wider shell than L. catasco- 

 pium, and the emargination visible on a profile view of the 

 umbilical groove is far more profound. In general obesity it 

 has a resemblance to L. hiflatus, Brong. It was first sent to 

 me by Mr. Aaron Stone, from the lakes of Maine. Dr. 

 Bigsby presented me with a specimen which he obtained in 

 Upper Canada ; and I have recently received several from Mr. Titian Peale, 

 also found in Maine, one of which is double the size of the figure repre- 

 sented in our plate 55, fig. 1. (Say.) 



Limnaea eniarginata, Say, Journ. Acad. Nat. Sc. II, 170 (1821) ; Long's 

 Ex. II, 63 ; Amer. Conch. VI, pi. Iv, f. 1 (1834).— Binney's ed. 67, 

 211, pL iv, f. 1.— Haldeman, Mon. 10, pi. ii (1841).— DeKay, N. Y. 



