BIVALVIA. 27 
P.Groenlandicus, Lovén and G. B. Sow., Thes. Conch., p. 57, Pl. 13, fig. 40, 
appears to differ from our shell only in being somewhat larger. 
4. PecTen TicRiNus, Miller. Tab. V, fig. 2, a—g. 
PECTEN TIGRINUS. 
Spec. Char. 
Miill. Zool. Dan., ii, p. 26, pl. 60, figs. 6—8, 1776. 
Desh. 2d ed. Lam., t. viii. p. 155, 1835. 
Nyst. Coq. Foss. de Belge, p. 303, pl. 23, figs. 4—10, 1844. 
Lovén. Ind. Moll. Scand., p. 31, 1846. 
Alder. Cat. of Moll. North. and Durh., p. 77, 1847. 
Ford. and Hanl. Hist. of Brit. Moll., vol. ii, p. 285, pl. 50, figs. 8—11. 
Penn. Brit. Zool., vol. iv, p. 322, t. 64, fig. 3. 
Don. Brit. Shells, vol. i, t. i, fig. 2, 1799. 
Mont. Test. Brit., p. 149, and sup., p. 57, 1808. 
Turt. Brit. Biv., p. 213, pl. 9, fig. 6, 1822. 
Brown. Wlust. Conch. Gr. Brit., pl. 33, fig. 6, 1827. 
J. Sowerby. Min. Conch. t. 541, figs. 1—8, 1828. 
Nyst. Rech. Coq. Foss. d’Anv., p. 19, No. 74, 1835. 
S. Wood. Catalogue, 1840. 
J. Morris. Cat. of Brit. Foss., p. 115, 1843. 
Thorpe. Brit. Mar. Conch., p. 118, 1844. 
parvus. Da Costa. Brit. Conch., p. 155, 1778. 
Lavis. Penn. Brit. Zool., vol. iv, p. 102. 
— Mont. Test. Brit., pp. 150, 579, pl. 4, fig. 1, 1803. 
— Turt. Brit. Biv., p. 212, 1822. 
— Brown. Ulust. Conch. Gr. Brit., pl. 33, fig. 7, 1827. 
pomesticus. Chem. Conch. Cab., t. xi, p. 261, pl. 207, figs. 2030—2036, 1783. 
OsTREA OBSOLETA. 
TIGERINA. 
Turt. edit. Linn., vol. iv, p. 266, 1806. 
W. Wood. Ind. Test., p. 50, pl. 10, fig. 37. 
Mawe. Linn. Conch., pl. 14, fig. 6. 
Turt. edit. Linn., vol. iv, p. 268, 1806. 
tavis. Mat. and Rack. Linn. Trans., vol. viii, p. 100, pl. 3, fig. 5, 1807. 
_ W. Wood. Ind. Test., pl. 10, fig. 38. 
Testi aquivalvi, equilateral, suborbiculari ; radiatd, radiis varies, 
interdum obsoletis, striis subtilissimis arcuatim divergentibus ornatd; auriculis valde 
inequalibus. 
Shell equivalve, equilateral, suborbicular ; costated coste variable, sometimes 
obsolete, or small and numerous, sometimes arranged in fives ; ornamented with fine 
curved and diverging stri, ears very unequal. 
Diameter, \ inch. 
Locality. Cor. Crag, Sutton, Ramsholt, Gedgrave, Sudbourn. 
Red Crag, Sutton, Bawdsey, and Walton Naze. 
Recent, Britain and North Seas. 
This is a very abundant species in the Coralline Crag, with as great a range in 
