158 TESTACEOUS MOLLUSCA. 
ribs, which are much narrower than the interstices, umbones 
oblique; posteriorly, obliquely rounded ventrally, rectangular dor- 
sally; emarginated anteriorly: ligamental area narrow and elon- 
gated anteriorly. 13.—Indian Ocean.— Much resembles Rhombea. 
A. Inequivatvis. Brug. dict. no. 16.—A. INnpica. var. 
D. p. 235.—Ch. f. 552.—E. t. 305. f. 3. a.—A. Impricarta. 
W.t.9.f.4. Obliquely heart-shaped, ventricose, inequivalve, one 
valve projecting beyond the other anteriorly, and at the rounded 
ventral margin; rather broader than long, anterior edge nearly 
direct, white, thin, with many nearly smooth and flattened ribs, 
beaks approximate. 22.—Indian Ocean. 
A. Inpica. Gimel. 3312.—D. p. 234.—Lam. 31.—W. t. 9. 
f. 21.—List. t. 232. f. 66.—Ch. f. 543. Transversely elongated 
ovate, inequivalve, thin, and whitish; with many ribs which are 
grooved in the middle, the beaks approximated and no area between 
them. 1..13.—Sumatra. 
A. Senturs. Lin. 1142.—D. p. 234.—Lam. 32.—Ch. f. 554. 
5, 6.—H#. t. 308. f. 1.—W. t. 9. f. 20. Obliquely heart-shaped, 
nearly as long as broad, tumid, thick, ponderous, white covered with 
a greenish brown epidermis, with about twelve broad very large 
unarmed ribs, of which seven or eight are much larger than the 
rest ; umbones large, obliquely recurved, and distant: within white 
and polished.— Diam. 23.—Africa. 
A. Brastziana. Lam. 33.—W. S.t. 2. f. 7.—A. INEQUIVAL- 
vis. Sow. Gen. f. 3. Inequivalve, heart-shaped, tumid, anteriorly 
subangulated, reddish white, with many flattened ribs which at the 
posterior side are crenulated, at the anterior unarmed: hgamental 
area pectinated. 12.— Rio Janeiro. 
A. CorsicuLa. Gmel. 3310.—A. CorsuLa. D. p. 235.— 
Lam. 34.—Ch. f. 559.—E. t. 309. f. 5. Ovate, subtrapeziform, 
the hinge margin nearly straight, and the rest of the margin 
rounded, white with radiating transversely striated ribs: beaks 
obtuse and approximated, the mtervening area very narrow. #..1. 
Cape of Good Hope. 
A. Sauamosa. Lam. 35.—An. Gray. in W. 8S. t. 2. f. 1221 
Ovate wedge-shaped, with cancellated striz, beaks tumid and 
approximated, anterior slope oblique, and imbricated with scales. 2. 
—-Nen Holland.2 
1 The shell from which this figure is taken, is again named by 
Mr. Gray in the British Museum A. Reticulata var. Are we to 
understood that these are synonymous ? 
2 Of this species, A. DomincEnsis, Lam. 16. is at most a 
variety (fide Deshayes). I add however the characters.—A. 
Domincensis. Lam. 16.—List. t. 233. f. 67. Transversely 
oblong, with decussated strie, reddish brown clouded with pale 

