LIMNEANA. MOLLUSCA. PHYSA. 211 



make it trumpet-shaped. Largest diameter / T inch, breadth V 

 inch. 



This curious little shell was found several years since on 

 the island of Nantucket, clinging to some damp moss, and was 

 communicated by Mr. J. M. Earle, of Worcester. Specimens 

 of it have also been sent to me by Professor Foreman, of Balti- 

 more. But its characters were not fully ascertained from these 

 few specimens. In July, 1840, Mr. T. J. Whittemore found it 

 in great numbers at Hingham, in a small pool, southeast of the 

 Old Colony House. 



It has a miniature resemblance to P. Mcarinatus as to its two sides, 

 but it has only a single carina, which encircles the shell, instead of one 

 on each side. Its large, expanded aperture, and small, deeply sunken 

 umbilicus, readily distinguish it from any of the small species hitherto 

 known. The surface is rather rough, and perhaps a little hispid 

 when viewed under the microscope. 



The P. lens of Lea (Amer. P kilos. Trans., New Series, vi. 68, pi. 

 23, f. 83), which he received from near Cincinnati, is probably the 

 same as this shell. His name, however, is pre-occupied by a fossil 

 species. 



GENUS PHYSA, DRAP. 



Shell reversed, oblong-ovate, spire prominent ; aperture rounded 

 before, narrowed and angular behind, lip sharp ; inner lip twisted. 

 Animal has thread-like tentacula, and the sharply lobed mantle is 

 turned back upon the shell. 



PHYSA HETEROSTROPHA. 



Shell ovate, smooth, yellowish-green ; ichorls four, inflated, 

 suture distinct, surface reticulated. 



FIGURE 141. 



State Coll., No. 73. Soc. Cab., No. 1306. 



Bulla fontinalis Indies Orientalis, CHEMN. ; Conch. , ix. 33, pi. 103, f. 879,880. 



Cochlea neritoides, LISTER ; Conch., pi. 135, f. 34. 



Bulla fontinalis, var. 3. GMELIN; Syst.,3407. SCHROET; Einl in Conch., t. 1, 



201, Helix, No. 84. 

 Bulla crassula, DILLWYN ; CataL, t. i. 487, No. 36. 



