LuciNOPSis. 435 



L. UNDATA, Pennant. 



Plate XXVIIl. fig. 1, 2, and (Animal) plate M. fig. 2. 



Venus imdata, Penn. Brit. Zool. ed. 4, vol. iv. p. 95, pi. 55, f. 51. — Mont. 



Test. Brit. p. 117.— Donov. Brit. Shells, vol. iv. pi. 121.— Linn. 



Trans, vol. viii. p. 86. — Turt. Conch. Diction, p. 241, f. 54. — 



Flem. Brit. Anim. p. 448. — Dilwyn, Recent Shells, vol. i. p. 



197.— Index Testaceol. pi. 8, f. 87.— Philippi, Moll. Sicil. vol. 



ii. p. 34. 

 Venus sinuosa, (monstrosity,) Penn. Brit. Zool. ed. 4, vol. iv. p. 95, pi. 55, f. 



51 A. — Mont. Test. Brit. p. 120.- Linn. Trans, vol. viii. p. 90. 

 Lucina undata,Tvwt. Dithyra Brit. p. 115. — Brit. Marine Conch, p. 73. — 



Brown, 111. Conch. G. B. p. 98, pi. 39, f. 1, 2.— Lam. Anim. 



s. Vert. (ed. Desh.) vol, vi. p. 229.— Hanl. Recent Shells, p. 76. 

 Venus incompta. Philippi, Moll. Sicil. vol. i. p. 44, pi. 4. f. 9. 

 Cytlierca umlata, Macgilliv. Moll. Aberd. p. 263. 

 Artemis undata. Alder, Cat. Northumberl. and Durham Moll. p. 84. 



The shape of this inelegant but peculiar shell, is sub- 

 orbicular, with a slight tendency to squareness. The valves 

 which are subventricose rather above the middle, become 

 depressed towards the lower margin, and lessen in con- 

 vexity almost equally on either side ; their surface, how- 

 ever, is not evenly curved, appearing somewhat angulated 

 owing to the slight flattening from the umbonal region 

 downwards, and a similar one at the posterior side. They 

 are opaque, brittle, more or less glossy, not very solid, and 

 of a paler or deeper fawn colour, irregularly wrinkled in a 

 concentric direction Avith very numerous and extremely fine 

 lines, and occasionally marked here and there with con- 

 centric very shallow somewhat pliciform indentations. 

 There is no other sculpture or division of surface what- 

 soever. The ventral margin is not very convex, and 

 usually rises rather the more in front ; the anterior dorsal 

 edge is more or less retuse, and rather strongly sloping ; 

 the hinder dorsal edge is almost straight, and scarcely de- 



