85 
very little elevated^ obtuse ; body whirl with minute transverse 
wrinkles^ and revolving impressed striae ; labium bidentate, the 
superior tooth transverse, prominent, terminating at the exterior 
edge of the columella ; labrum with four or five elevated striae, 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 
them to be very numerous near the mouth of St. John’s river. 
It is sufficiently distinct from the M. coniformis 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. 
G-reat 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 columella, and nearly covers the umbilicus from above ; 
umbilicus with a profound sulcus or duplication. 
Greatest length about two inches. Greatest breadth rather 
more. Inhabits the coast of the United States. Cabinet of the 
Academy and Philadelphia Museum. 
