TRIBE NYMPHACEA. Of) 



same colour ; nymphse 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 . . 2f. Young and more 

 oblon<*. — (Chloroleuca. Lam.) — European and Indian Seas, 



T. Lingua-felis. Lin. 1116. — D. p. 73. — Lam. 37.— E. t. 

 289./. 6.— Ch.f. 65.— Wood. G. C. t. 40./. 2, 3.— W, t. 3./. 2. 

 Roundish ovate, with the anterior extremity very obtuse ; roughened 

 by lunated scales disposed in quineunxes and rayed with pale pink 

 oil a whitish ground ; beaks pink. 1J . . If* — India. 



T. Rugosa. Born. t. 2. f. 3, 4. — D. p. 73.— Lam, 38.— 

 Wood. G. C. f. 41./. 2, 3.—E. t. 290./. \.— Ch.f, 62.— W. t.3. 

 f. 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.— TF. t 3. f. 12.— 

 T. Papyracea. Gmel. 3231.— E. t. 290./. 14.— Ck, 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-f . . 2-i.— Guinea, 



T. Gargadia. Lin. 1116. — D. p. 72.—Ch.f. 63, 4.— Lam. 

 40. — W. t. 3./. 1. Roundish-ovat-e, compressed, cartilage slope 

 toothed, transversely and undulatingly wrinkled on the anterior 

 side and towards the ventral margin. 1£ . . 1|-. — Nicobar Isles. 



T. Pristis. Lam. 41. — E. t. 287./ 1. — White, roundish-ovate, 

 anteriorly angulated and shorter, with sub-imbricated transverse, 

 and minute radiating striae, 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. 1 J. — Indian 

 Ocean. 



T. Polygona.— Chem. / 77.- D. p. 76-— W. t. 3. /. 11.— 

 Multangula. 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. 1£ . . 2\. — Tranqnebar. 



T. Guinaica.~ Chem.f. 1651, 2, 3.—D.p. 96.— T. Polygona. 

 Lam. 43.— Gmel. 3244.— Mont. t. 28. /. 4,— W, t.4.f. 80.? 

 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- 



