200 TESTACEOUS MOLLUSCA. 
mental edge in the young, nearly straight and subangulated at the 
extremities. 
U. Conrertus. Lea. Trans. Am: Ph. 5.t.16.f.47. Trape- 
zoidal, transverse, inequilateral, inflated, cats beaks slightly 
elevated and transversely wrinkled, umbones much swollen, liga- 
ment rather short and thin ; eniicle dark brown, shining, nacre 
purple or salmon; cardinal teeth COMIpressEd and double in both 
valves, the lateral long and curved. 1 3,..2%.—S. Carolina.) 
U. Funvus. Lea. Tr. Am. Ph. 5. t. 13. J. 39. IcrERinus. 
Con. Narrow elliptical, transverse, inequilateral thinnish, subin- 
flated, rounded posteriorly, angulated anteriorly, ventral edge entire, 
dorsal straight, umbonal slope rounded, beaks slightly elevated ; 
cuticle yellow and yellowish brown, nacre salmon: cardinal teeth 
oblique, the lateral somewhat curved. 9, ..12.—S. Carolina. 
U. Concaramus. Lea. on U.1. p. 82.(and Tr. Am. Ph. 4.) 
t. 6. f. 4.  Elliptico-rhomboidal, transverse, inequilateral, thin, 
somewhat flattened at the sides, anteriorly slightly sinuated, the 
slope and beaks with slight undulations ; ventral edge little rounded; 
ligament short: cuticle yellow and yellowish brown, with numerous 
green rays: nacre satinlike and irridescent : cardinal tooth oblique 
and compressed, the lateral long and enlarged anteriorly. 1 ..13.— 
S. Carolina. 
U. Decuivis. Say. Am. C. t. 35.—U. Gromerricus. Say. 
Transverse, thickish, posteriorly short and rounded, ligamental edge 
rectilinear very slightly (if at all) elevated and forming a sharp 
angle with the anterior edge which runs down obliquely to the 
entire and but slightly rounded ventral edge : umbonal slope not 
elevated ; surface deeply wrinkled : inside just tinged with pur- 
plish; cardinal teeth oblique, the lateral distant, rectilinear, oblique. 
21.—N. America. 
U. Buanpineranus. Lea. Tr. Am. Ph. 5, t. 15. fi 44. Sub- 
trapezoidal, transverse, very inequilateral, thin: beaks somewhat 
prominent : cuticle fuscous, wrinkled, nacre dull purple: cardinal 
teeth compressed, the lateral long and curved. 13. . 2,8;.—Florida. 
U. Depressus. Lam. 38,.—D’ Orb.—Lesson. voy. de Coq. t. 
15. f. 55? Ovate-oblong, depressed, thin, rounded at the extremi- 
ties of the sides : cuticle brown, nacre bluish. 2.—New Holland. 
U. Aneustus. Lam. 42.—an List, t. 147. f. 3. Transversely 
oblong, narrow, subsinuated, anteriorly with two obsolete angles, 
extremities of the sides rounded; cuticle yellowish brown, slightly 
striated longitudinally on the depression in the middle. 22. 

1 Add likewise the U. Paxniatus of Ravenel’s letter, and the U. 
WarrreEnsis of Lea, the Ravenili of Conrad. 
2 Add likewise the U. Mopestus of Ferussac. 
