196 MOLLUSCA FROM THE CRAG. 



1. Cypkina Islandica. Linn. Tab. XVIII, fig. 2 c— </. 



Pectuncclus MAXIMU3. List. Hist. Conch., fig. 108. 1685. 



— — Dacosta. Brit. Conch., p. 183, t. xiv, fig. 5, 17/8. 



Vexcs Islandica. Linn. Syst. Nat., ed. 12, p. 1131, No. 124, 1/07. 



— — Mull. Zool. Dan., vol. i, p. 29, pi. xxviii, figs. 1 — 5, 177C. 



— IcELANDiCA. n^. Wood. Inil. Test., pi. vii, fig. 4), 1825. 



— MERCENAKIA. Penn. Brit. Zool., ed. iv, vol. iv, p. 94, pi. liii, fig. 47. 



— BCCAKDIUM. Born. Mus. Cms. Vind., t. iv, fig. 11, 1780. 



— EQCALis. J. Sow, Min. Conch., t. xxi, 1813. 

 Cyprina Islandica. Ency. Meth., pi. 301, fig. 1 a, b, 1789. 



— — Phil. En. Moll. Sic, vol. ii, p. 31, 1844. 



— — Ki/st. Couch. Foss. de Belg., p. 146, pi. ix, fig. 1, and pi. ii, fig. 1, 



1844. 



— — Agass. Icon, des Coq. Tert., p. 49, t. xiii, figs. 6, 7, 1845. 



— — Dekay. Nat. Hist. New York Zool., pi. xxvi, figs. 268-9, 1843. 



— — Lovhi. Ind. Moll. Scand., p. 38, 184G. 



— IsLANDicoiDES. Nijst. Coq. Foss. Prov. d'Anv., p. 9, No. 33, 1835. 



— — Pusch. Pol. Pal., p. 74, pi. viii, fig. 5 a — c, 1837. 



— angclata. N}jst. Rech. Coq. Foss. d'Auv., p. 9, No. 34, 1835. 



— MAXIMA. S. TFood. Catalogue, 1840. 



— VULGARIS. G. B. Sow. Genera of Shells, No. 32, 1824. 



— jEauALis. Phil. En. Moll. Sic, vol. i, p. 39, t. iv, fig. 4, 1836. 



— — Gold/. Pet. Germ., p. 236, pi. 148, fig. 5, a, h. 



— — Agass. Icon, des Coq. Tert., p. 52, t. xiii, fig. 5, 1845. 



Arctica VULGARIS. Schum. Essai d'un Nouv. Syst. des Habit, des Vers. Test., p. 145, 

 pi. xiii, fig. 3, 1817. 



Spec. Char. Testa magna, subcordatd, transversa, vel orbiculari, tuviidivsculd ; striis 

 ant lineis incrementi tenuibus et irreffularibus ; umbonibus acutis viw inairvatis ; latere 

 postico subant/ulato. 



Shell large, of a subcordatc form, sometimes elongate or transverse, at others 

 nearly orbicular, somcwliat tumid, covered with fine and irregular lines of growth ; 

 beaks sharp, not prominent, scarcely incurved, posterior side shghtly angulated. 

 Diameter, 4^ inches. 

 Localities. Cor. Crag, Gedgravc, Ramsholt. 



Red Crag, Sutton, Bawdscy, Alderton, Fclixstow. 

 Mam. Crag, Bridlington, Southwold, Chillesford. 

 Uddcvalla and Clyde Beds. 

 Recent, British, Norwegian, and North American Seas. 

 This is one of the most common and abundant shells of the Coralline Crag, and 

 although perfect specimens are somewhat difficult to obtain in the disturbed portion 

 of the Red Crag, fragments or imperfect specimens are there of no uncommon occur- 

 rence, neither is it very rare in the still more recent deposit of the Mammalifcrous 

 Crag. It is found living upon our own coasts in various depths of water from five to 

 thirty fathoms, and mostly where the bottom is of sandy mud, but it is considered as 



