Fossil and Recent Shells. 345 
dermis; anterior and posterior sides each with an obscure fold; beaks 
central, not elevated; hinge edentulous; anterior muscular acs 
sion not greatly sbioasttis Length, one inch. 
» This shell resembles the fossil LZ. anodonta, of Say, but is very | 
distinct. It was found near Pensacola by Dr. Hutchins, who sent 
it to Dr. S. G. Morton. 
EREA. 
C..Sayana. Shell subovate, convex, with coarse concentric lines, 
and destitute of polish ; lunule large, cordate, marked by a simple im- 
pressed line; hinge, with the teeth compressed. Length, one inch 
and one fourth. — 
Syn. CyTHEREA CONVEXA, Boy: Jour. Acad. Nat. Sciences, vol. 
iv, p. 149. 
‘Found on the coasts of Rhode Island and New Jersey; it is pale 
yellowish or white and appears not to differ specifically from the C. 
convexa, of Say, but I have changed the name because M. ioe 
niart had previously applied it toa very. dissimilar species. 
MELAMPUS. 
M. borealis. Shell ovate —_ elongated ; pale horn ee 
darker longitudinal bands; v six or seven, with a rev 
pressed line below the suture; spire elevated, conical ; scheme 
with three distant and distinct plaits, the middle one most prominent; 
aperture obovate-acute. Length, one fourth of an inch. 
This small species of Melampus has been found sparingly on the 
coast of Rhode Island, by Lieut. Brown of Newport. Itis similar 
in form to a Bulimus and is very unlike the common species with 
which it associates. 
~—Ungulina transversa. Lam. As the sense of this rare shell is 
rather obscure, it may be worthy of remark, that I discovered two 
specimens in a piece of limestone, inhabiting cavities which appeared 
to have been formed by themselves. ‘The limestone was perforated 
-in every direction by shells of the genera Arca, Crendtula, Veneru- 
pis, Petricola, &c., all the species being such as are common in the 
West Indies, from whence no doubt, the stone thik contained them 
had been brought. From the circumstance of its occurring in this 
Situation and from the peculiar form of the shells, I have no doubt 
that the genus Ungulina may be properly classed among the litho- 
phagous Testacea. 
‘Lima glacialis. Lam. It is a singular fact in the history of this 
shell that although it swims with or ease and rapidity, it is often 
Vou. XXIIL.—No. 2 
