190 TESTACEOUS MOLLUSCA. 
U. Sprenpipus. Lea. on U. 2. p. 70. t. 19. f. 61.  Ellip- 
tical, very inflated, thickish, inequilateral, ventral edge somewhat 
rounded ; beaks prominent, anterior slope with three indistinct 
ribs ; umbonal slope carinated: cuticle yellowish covered with 
numerous dark green rays, nacre rosy; cardinal teeth somewhat 
compressed, the lateral separate and lamellar. 1. .24—Greor- 
gia in America. 
U. Ocuraceus. Say. in Nic. Enc. Am. Cone. t. 2. f. 8.— 
Conr. Mon. U. t. 17. f. 2.—Sympnonota O. Lea. on U. 1: 
p. 69. Subovate, inequilateral, transversely wrinkled, inflated, 
thin, connate before the ligament which is not concealed, not 
winged ; beaks full and prominent, with several concentric undu- 
lations: cuticle glossy, varying from yellow ochre to brown ochre, 
with oblique rays which anteriorly are more numerous, nacre bluish 
white and ochraceous ; cardinal and lateral teeth forming a curved 
line. 159,. . 249,.—Delanare. 
U. Carrosus. Say. Enc. Am.—Am. C. t. 3. f. 2.—Barnes. 
—Lam.—Uv. Lurroua. Conr. Ovate or oval, not very thick, 
anteriorly longer, (and usually dilated) dises swelled, umbones 
elevated; cuticle olive brown, or greenish, usually rayed with 
green, nacre bluish white, often white reddish rose or salmon ; 
ligament elevated : cavity moderate. 2,35 .. ,'5.—N. America. 
U. Perovatus. Conr. N. F. W. p. 47. t. 2. f. 3.—Sil. 
Jour. 25.t. 1. f. 3. Transverse, ovate, rather ventricose, thick 
but thinner on the anterior side, which is longer attenuated and ob- 
tusely subangulated above and below; ventrally and posteriorly 
rounded, beaks rather elevated, approximated and undulated : cuti- 
cle olive, wrinkled on the margin, nacre white: cardinal teeth 
erect and prominent, not very thick. 2.—It. Alabama. 
U. Attinis. Conr. N. F. W. 8. p. 43. t. 2. f. 1. Transverse, 
suboval, thin, inflated, beaks slightly prominent and much dilated ; 
anteriorly longer dilated and obtusely subangulated, ventral edge 
arcuated and entire, umbonal slope rounded, behind which is an 
obscure radiating rib: cuticle blackish, rugose, olivaceous over the 
umbones and rayed with short vermicular lines on the anterior slope, 
nacre whitish and irridescent ; cardinal teeth subpyramidal, erect, 
the lateral distant. 2.—Alabama. 
U. Muutirapiatus. Lea. on U.1.p. 48. t. 9. f.15.—U. Fas- 
cioLus. Conr. Mon. U. t.11.f.2.—U. Ligamentina. Desh. 
Elliptical, transverse, inequilateral, ventricose, thin, anteriorly ob- 
tuse, posteriorly and ventrally rounded ; beaks prominent and 
slightly undulated, cuticle olive yellow covered with green rays, 
nacre bluish white : cardinal teeth erect and double in both valves, 
the lateral lamelliform and abrupt. 1515... 2.—Ohio. 
U. Novi Esporact. Lea. on U. 2. p. 104. t. 24. f. 114. Ellip- 
tical, somewhat compressed, inequilateral, thickish, posteriorly 
