236 MOLLUSCA FROM THE CRAGi. 



Mya Hispanica. Chemn. Conch. Cab., torn, vi, p. 31, t. 3, fig. 21, 1782. 



— oRBiciLATA. Speng. N. H. S. Sk. II., i, p. 38, No. 13, sec. Schum. 



— Gaditana. Gmel. Syst. Nat., p. 3221, 1788. 



SoLEK c^LLOSDS. Olivi. Zool. Ailriat., p. 98, t. 4, figs. 1, k — c, 1792. 

 Mactra Listeri. Gmel. Syst. Nat., p. .■J2G1, 1788. 



— — JVoodw. Geol. of Norf., p. 43, t. 2, fig. 7, 1833. 



— riPEKATA. Gmel. Syst. Nat., p. 3261, 1788. 



— COMPUESSA. Mont. Test. Brit., pp. 96 and 570, 1803. 

 LiuuLA co.\iPKEssA. Moiit. Test. Brit. Supp., p. 23, 1808. 

 Tellina PI.A.NA. Don. Brit. Shells, pi. 64, fig. 1, 1801. 

 LuTRAKiA compressa. Lamk. Au. s. Vert., torn, v, p. 469, 1815. 

 LiSTERA COMPRESSA. Turt. BHt. Biv., p. 51, pi. 5, figs. 1, 2, 1822. 

 Lutkicola compressa. BUiinv. Malac, pi. 77, fig. 2, 1825. 

 Ampuidesma compeessu.m. Flem. Brit. An., p. 432, 1828. 



— TRANSVERSUM? Say. Amer. Conch., pi. 28, mid. fig. 

 Lavignon cai.cinei.la. lieduz. Illust. Conch, p. 8, pi. 1, fig. 1. 



ScROHicuLAUiA AitEXAUiA. Schutti. Essui d'uu Nouv. Syst. des Vers., p. 127, pi. 8, 



fig. 3, a, b, 1817. 



— PI PER ATA. Phil. En. Moll. Sic, vol. ii, p. 8, 1844. 



— — Forb. and Hani. Hist. Brit. Moll., vol. i, p. 326, pi. 15, fig. 5 ; 



and pi. K, fig. 6, 1848. 



— PLANA. Alder. Cat. Moll. North, and Diirh., p. 90, 1848. 



Aura Listeri. "Leach" 1819. Ann. and JIag. Nat. lli.sl., 1817, vol. .\-.\, p. 272. 

 La CALciNELi.E. Adans. Senegal, p. 232, t. 17, fig. 18, 1757- 



Spec. Char. Testa ovatd, transversa, compressa, subcsquilaterali, concentrice striata ; 

 cardine hidentato ; sinii palliari maff no, prof undo. 



Shell ovate, transverse, compressed, nearly equilateral, concentrically striated ; 

 hinge with two teeth ; ])alleal sinus large and deep. 



Lenffth, \\ inch. Height, \~ inch. 



Localifi/. (?) Red Crag, Sutton. 



Mam. Crag, Bramcrton, Chillesford. 



Clyde Beds. Recent, Mediterranean, Britain, and Scandinavia. 



One specimen only of this long-known and common recent species was found by 

 myself, many years ago, and, I think, in the Red Crag at Sutton. I believe it is not 

 rare in the neighbourhood of Norwich. As the living species is subject to consider- 

 able variation in its outward form, there is no difliculty whatever in finding the exact 

 resemblance of our fossil among recent specimens. The habits of the living animal 

 lead it almost exclusively to the estuary portion of the sea, which may perhaps be a 

 reason why it has not been more frequently met witli. I have obtained one specimen 

 from Clacton, in association with U/iio, Cardium, S^c. There is a slight difference 

 in the tumidity of the two valves, causing thereby a dififcrence in the pallcal impression, 

 like that in some of the Tellens. 



