134 MOLLUSCA FROM THE CRAG. 



1. Cryptodon sinuosum, Donovan. Tab. XII, fig. 20, a, b. 

 Venus sinuosa. Don. Brit. Shells, t. 42, fig. 2, 1801. 

 Tellina flexuosa. Mont. Test. Brit., p. 72, 1803. 



— — Mat. and Rack. Linn. Trans., vol. viii, p. 56, 1807. 



— — Turt. Conch. Diet., p. 177, 1819. 



_ _ W. Wood. Ind. Test., p. 22, pi. 4, fig. 78, 1825. 



Amphidesma flexuosa. Lam. Hist. Nat. des An. s. Vert., t. v, p. 492, 1818. 

 Thyasira flexuosa. " Leach, MS.," Lam. Loc. cit. Sup., t. v, p. 492, 1818. 

 Lucina sinuata. Lam. Loc. cit., t. v, p. 543, 1818. 



— — Brown. Illust. Brit. Conch., pi. 17, figs. 4, 6, 1827. 



— sinuosa. Forbes. Report on iEgean Invert., p. 182, 1843. 



— — Thorpe. Brit. Mar. Conch., p. 74, 1844. 



— flexuosa. Flem. Brit. Ann., p. 442, 1828. 



— — Gvuld. Invert. Massach., p. 71, fig. 52, 1841. 



— — Forb. and Hani. Hist. Brit. Moll., vol. ii, p. 54, pi. 35, fig. 4, 1849. 



— — Reeve. Conch. Icon. Lucina, pi. xi, fig. 62. 



— Sarsii. Id. - pi. ix, fig. 52. 



— Goodhalli. J. Soio. Geol. Trans., 2d Ser., vol. v, pi. 8, fig. 7, 1834. 

 Cryptodon flexuosum. Turt. Brit. Biv., p. 121, pi. 7, figs. 9, 10, 1822. 



— — Brown. Illust. Brit. Conch., 2d ed., pi. 39, figs. 4, 5. 



— — Mailer. Ind. Moll. Groenl., p. 20, 1842. 



— — Alder. Cat. Moll. North, and Durh., p. 91, 1847. 



— bisinuatum. S. Wood. Catalogue, 1840. 



Ptychina biplicata. Phil. En. Moll. Sic, vol. i, p. 15, t. 2, fig. 4, 1836. 

 Axinus unicarinatus. Ntjst. Rech. Coq. Foss. d'Anv., p. 6, pi. 1, fig. 22, 1835. 



— Benedenii. De Koninck. Des. Coq. Foss. Arg. Boom, p. 35, pi. 11, figs. 2, 3, 



1837. 



— angulatus. Nyst (not Soiverby). Coq. Foss. de Belg., p. 141, pi. 6, fig. 13, 1844. 



— — Michel. Desc. des Terr. Mioc. de l'ltal. Septen. (Haarlem Trans.), 



p. 118, pi. 4, figs. 23, 23*, 18-47. 



— flexuosus. Loven. Ind. Moll. Scand., p. 38, 1846. 



— Sarsii. Id. - p. 38, ,, 



Spec. Char. Testa ovato-orbiadari vel subhexagond, lavigafd, tenui, subpellucidd, 

 tumidd, subaquilaterd ; latere postico biplicato, margine ventrali producto, lunula cordato- 

 ovatd, magna, impressd. 



Shell ovately orbicular, with an irregularly hexagonal outline, smooth, thin and 

 subpellucid, tumid, and nearly equilateral ; posterior side with two folds or furrows, 

 ventral margin produced, and a large and deeply impressed heart-shaped lunule. 



Diameter, \ an inch. 



Locality. Cor. Crag, Sutton. 



Recent, iEgean Sea, Britain, Scandinavia, and North America. 



This species is not at all abundant. There is no doubt of its identity with the recent 

 British shell, and I have given it as an inhabitant of the North West Coast of 

 America, upon the authority of that accurate observer, Dr. Gould. A specimen 



