85 



very little elevated, obtuse ; body whirl with minute transverse 

 wrinkles, and revolving impressed strias ; labium bidcntate, the 

 superior tooth transverse, prominent, terminating at the exterior 

 edge of the columella ; labrum with four or five elevated stria?, not 

 attaining the edge ; base not contracted. 



Length nine-twentieths of an inch. 



Animal about as long as the shell, and the foot is transversely 

 bifid ; tentacula somewhat wrinkled, cylindrical, rather smaller to- 

 wards the tips, which are obtuse or rounded; eyes placed at the 

 inner base of the tentacula ; rostrum somewhat wrinkled, nearly as 

 long as the tentacula, bi-lobate before; foot, anterior segment 

 emarginate behind, posterior segment bifid at the extemity; all 

 above, with the exception of the tenacula and rostrum, glabrous, 

 reddish-brown, beneath paler. 



Inhabits East Florida. Cabinet of the Academy and Philadel- 

 phia Museum. 



Var. a. With three or four fuscous revolving lines ; base of the 

 aperture narrower than in the species. 



Length seven-twentieths of an inch. Inhabits the coast of 

 Maryland and New Jersey. 



These shells inhabit the salt marshes, and have the habit of 

 crawling up the culms of grasses, and other plants. I observed 

 theiu to be veiy nvimerous near the mouth of St. John's river. 

 It is sufficiently distinct from the M. conifortnis by the paucity of 

 striae on the labrum. 



The variety is a very common inhabitant of our coast, and is 

 very possibly a distinct species, as it is lineated and is narrower at 

 base ; if so, it may be called lineatus. 



Grreat numbers of this species are devoured by the dusky duck 

 (Anas obscura,) and perhaps by other birds. 



Natica DUPLICATA. — Shell thick, sub -globose, cinereous, with 

 a black line revolving on the spire above the suture, and becoming 

 gradually diluted, dilated, and obsolete in its course ; within brown- 

 ish-livid ; a large incrassated callus of the same color extends 

 beyond the colimiella, and nearly covers the umbilicus from above ; 

 umbilicus with a profound sulcus or duplication. 



G-reatest length about two inches. Greatest breadth rather 

 more. Inhabits the coast of the United States. Cabinet of the 

 Academy and Philadelphia Museum. 



