1818] CRUSTACEA OF THE UNITED STATES. 245 



of the museum of South Carolina was found by Mr. 

 L'Hermenier on the coast of that state. The specimen 

 in the collection of the Academy we found on the coast 

 of Amelia Island, Florida, concealed under a considera- 

 ble mass of Ascidia; when placed in water, the thicker 

 filament of the superior antennas was supported in an 

 erect posture, vibratory, and appeared deeply ciliated 

 near the tip. 



I have placed this in the genus Alpheus of Fabricius 

 and Latreille, as the characters will not agree with those 

 ascribed to that genus by Dr. Leach, such as •^ exterior 

 caudal lamella simple; third segment of the abdomen 

 gibbous above," &c. the antennae also are relatively 

 situate as in Astacus^ and the scale at the base of the 

 outer antenna is not proportionably larger than in that 

 genus. 



2. A. * minus. Hands of the anterior feet very unequal, 

 larger one inflated, oblong-oval, equal; carpus very small; 

 rostrum spiniform, and a lateral spine before the eye. 



Inhabits coasts of the southern states, and of East 

 Florida. 



Cabinet of the Academy. 



Thorax glabrous, rostrum and convex lid of the eye 

 forming three subequal spines before, of which the ros- 

 trum is somewhat longer and more acute, the lateral spines 

 conic-acute; exterior antenncs shorter than the body, 

 scales at base acute, spiniform; larger hand oblong- oval, 

 not compressed, colour white, tip red, banded near the 

 base of the fingers with white in the female, and white 

 tipped with green in the male, nails short; external pedi- 

 palpi obtuse at tip and crowned with spines. 



