236 MOLLUSCA FROM THE CRAG. 



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



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



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



Solen callosus. Olivi. Zool. Adriat., p. 98, t. 4, figs. 1, a — c, 1792. 

 Mactra Listeri. Gmel. Syst. Nat., p. 3261, 1788. 



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



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



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

 Ligula. compressa. Mont. Test. Brit. Supp., p. 23, 1808. 

 Tellina plana. Don. Brit. Shells, pi. 64, fig. 1, 1801. 

 Lutraria compressa. Lamk. An. s. Vert., torn, v, p. 469, 1815. 

 Listera compressa. Turt. Brit. Biv., p. 51, pi. 5, figs. 1, 2, 1822. 

 Lutricola compressa. Blainv. Malac, pi. 77, fig. 2, 1825. 

 Amphidesma compressum. Flem. Brit. An., p. 432, 1828. 



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



Lavignon calcinella. Recluz. Illust. Conch, p. 8, pi. 1, fig. 1. 



Scrobicularia arenaria. Schum. Essai d'un Nouv. Syst. des Vers., p. 127, pi. 8, 



fig. 3, a, b, 1817. 



— piperata. 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 Durh., p. 90, 1848. 



Abra Listeri. "Leach," 1819. Ann. and Mag. Nat. Hist., 1847, vol. xx, p. 272. 

 La calcinelle. Adans. Senegal, p. 232, t. 17, fig. 18, 1757. 



Spec. Char. Testa ovatd, transversa, compressa, sub ce quit aterali, concentrice striata ; 

 cardine bidentato ; sinu palliari magno, prof undo. 



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

 hinge with two teeth ; palleal sinus large and deep. 



Length,, \\ inch. Height, lj inch. 



Locality. (?) Red Crag, Sutton. 



Mam. Crag, Bramerton, 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 difficulty 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 with. I have obtained one specimen 

 from Clacton, in association with Unio, Cardium, 8fc. There is a slight difference 

 in the tumidity of the two valves, causing thereby a difference in the palleal impression, 

 like that in some of the Tellcns. 



