150 AMERICAN MARINE CONCHOLOGY. 
A doubtful species, of which only one specimen was received by 
Mr. Say. 
8. T. DECORA, Say. Figs. 358, 359. 
Journ. Philad. Acad., vy. 219. 1826. 
Transversely subovate, not much compressed, with numerous 
minute concentric wrinkles and regular equidistant lines crossing 
them ; no oblique lines on the posterior margin. Anterior lateral 
tooth of the left valve prominent, the others obsolete ; apex a little 
before the middle. Rosaceous, or white with rosaceous radiations. 
Length 22, height 19 mill. 
Southern Coast. 
9. T. LATERALIS, Say. 
Journ. Philad. Acad., v. 218. 1826. 
Shell transversely subovate; beaks nearly central. Anterior 
margin regularly rounded ; posterior margin rostrated, the beak 
turning to the left and slightly gaping; ligament slope straight ; 
basal margin regularly arcuated. Valves with small concentric 
wrinkles and slight waves; within, these are slightly impressed. 
Lateral teeth none; cardinal teeth two in one valve, and one, with 
another scarcely elevated filiform tooth in the other. Whitish, 
often tinged with rusty; within white. 
Length 52, height 37 mill. 
Southern Coast. 
I am not acquainted with this species. 
10. T. LusoRIA, Say. Fig. 360. 
(Psammobia.) Journ. Philad. Acad., ii. 304. 1822. 
‘Shell oblong, suboval, with minute wrinkles; posterior side 
narrowed, and inclining to the right at the end; an obtuse convex 
line on the left valve. Bluish-white. 
Length 1, height .6 inch. 
: New Jersey to Florida. 
Doubtful Species. } ; 
11. T. veRstcoLor, Cozzens. Fig. 361. 
DeKay, Moll. N. Y. 209, t. 26, f. 272. 1843. 
Shell, transverse, compressed, inequilateral, slightly gaping at 
its subacute extremity, smooth, posterior end subangular, with 
an indistinct fold; anterior extremity dilated and rounded. Car- 
dinal teeth two in the right valve; the posterior more robust, 
simple, in the left valve rudimentary or inconspicuous. White, 
