TRIBE NYMPHACEA. 69 
same colour; nymph inflected; within white with a tinge of 
citron at each extremity: hinge with two cardinal teeth in each 
valve and the lateral teeth approximate. 2..23. Young and more 
oblong.—(CuLoroLevuca. Lam.)—European and Indian Seas. 
_ T. Lineva-renis. Lin. 1116.—D. p. 73.—Lam. 37.—E. t. 
289. f. 6.—Ch. f. 65.— Wood. G. C. t. 40. f. 2, 3.—W. t. 3. f. 2. 
Roundish ovate, with the anterior extremity very obtuse ; roughened 
by lunated scales disposed in quineunxes and rayed with pale pink 
on a whitish ground; beaks pink. 1}..13:—Jndia. 
T. Rucosa. Born. t. 2. f. 3, 4.—D. p. 73.—Lam. 38.— 
Wood. G.C.t. 41. f. 2, 3.—E. t. 290. f. 1.— Ch. f. 62.—W. t. 3. 
Ff. 8. Roundish-ovate, anteriorly attenuated and inflected, with 
transverse undulated membranaceous wrinkles, white tinged with 
yellow at the beaks; inside white ; hinge with a cleft and plain 
tooth in one valve, and two plain with strong lateral ones in the 
other.—New Holland. 
T. Lacunosa. Lam. 39.—D. p. 76.—W. t. 3. f. 12.— 
T. Papyracea. G'mel. 3231.—LH. t. 290. f. 14.—Ch. f. 78. 
Roundish-ovate, rounded at one end and sub-truncated at the 
other, whitish, thin, ventricose and transversely striated; the 
ventral margin depressed in the middle, with a sinuous twist. 
1} ..24.— Guinea. 
T. Garegapia. Lin. 1116.—D. p. 72.—Ch. f. 63, 4.—Lam. 
40.—W. t. 3. f. 1. Roundish-ovate, compressed, cartilage slope 
toothed, transversely and undulatingly wrinkled on the anterior 
side and towards the ventral margin. 14..13.— Nicobar Isles. 
T. Pristis. Lam. 41.—E. t. 287.f. 1.—White, roundish-ovate, 
anteriorly angulated and shorter, with sub-imbricated transverse, 
and minute radiating strie, the former becoming fine ridges on the 
obliquely truncated anterior slope, whose depression is lanceolate 
and concave, and its edge seemingly toothed ; hinge with a bifid 
and lamellar tooth in each valve besides lateral ones. 13.—Indian 
Ocean. 
T. Potyeona.— Chem. f. 77.—D. p. 76.—W. t. 3. f. 11.— 
Muttraneuta. Lam. 42.—Gmel. 3230. Ovate broadly tri- 
angular, the anterior side the longer, sinuous, and almost biangu- 
lated ; white with the beaks and margin yellowish, transversely 
striated and somewhat decussated towards the margin: hinge with 
a single cleft cardinal tooth in one valve and two in the other, no 
lateral teeth. 13 ..24.—TZvranquebar. 
T. Gurnatca. Chem. f. 1651, 2, 3.—D. p. 96.—T. Potyeona, 
Lam. 43.-—Gmel. 3244.—Mont. t. 28. f. 4.—W. t. 4. f. 80.2? 
Roundish-ovate, somewhat triangular, flexuous and sinuated at 
the ventral margin, white with the beaks and interior tinged with 
pale orange, transversely striated ; hinge with two large cardinal 
teeth in one valve and a large triangular cleft one, with an approxi- 
