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Lengtli one and one-twentietli inches ; breadth one and seven- 
twentieths inches. Inhabits the estuaries of G-eorgia. Cabinet of 
the Academy and Philadelphia Museum. 
Several specimens of dead shells were brought up from the 
bottom of the Sound, near Jeykill island, by the fluke of our 
anchor. 
Amphidesma radiata. — Shell transversely oval, orbicular, a 
little compressed ; apex nearly central, a little prominent ; posterior 
slope somewhat concave near the beak j anterior slope rectilinear 
to the middle ; disk somewhat regularly wrinkled transversely, and 
with minute longitudinal striae, white, with more or less rosaceous 
radii, which are sometimes obsolete ; anterior submargin, with a 
slight very obtuse undulation ; cardinal teeth two in each valve, 
elevated, slender, unequal ; lateral teeth very distinct ; the poste- 
rior one nearer the primary teeth, and shorter than the anterior 
one ; interior ligament cavity profound, fusiform, nearly parallel 
to the anterior slope ; within tinged with yellow, and the rosaceous 
radii are distinct. 
Length nine-tenths inch ; breadth rather more than one inch. 
Many specimens of this pretty species were brought from the 
Southern shores of East Florida, by Mr. Titian Peale, and I ob- 
tained a worn individual a few years since, on the coast of Greorgia, 
measuring one inch and two fifths in breadth. 
It resembles the species I formerly described under the name of 
A. orhiculata, but it is wider in proportion to the length, &c. 
Amphidesma lepida. — Shell very much compressed, subtri- 
angular, remarkably thin, pellucid, equilateral, somewhat iridescent, 
with numerous concentric wrinkles, and equally numerous very 
minute regular, longitudinal striae, which, on the anterior margin, 
curve towards the anterior edge, and on the posterior margin curve 
in the same manner towards the posterior edge ; cardinal teeth 
obsolete ; lateral teeth prominent. 
Length rather more than one-fourth of an inch ] breadth less 
than one-fourth of an inch. 
This shell was sent to me by Mr. Elliott, who found it on the 
coast of South Carolina. 
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