BIVALVIA. 279 



remarkable that the specimens of Panopea Norveffica found at this locaUty, where 

 the general remains are decidedly of an Arctic character, have this side much 

 abbreviated. 



In the recent state it is found, sparingly, on the coast of the United States ; and 

 M. Middendorff* describes it as an inhabitant of the Sea of Okhotsk and the Behring 

 Straits, appearing principally confined to the colder regions of the Northern 

 Hemisphere. 



This is the elder of the two species, and has in the living state a great 

 geographical range, extending from the Behring Straits, through the Scandinavian 

 and British Seas, to the coast of the New World westward, through Davis's Straits, 

 and as far as Baring Island, where the short variety has been found in abundance. 

 It is thus spread over an area of 280 degrees of longitude, and its range in depth is 

 upwards of 100 fathoms. It was formerly an inhabitant of the seas which deposited 

 the Sicilian Beds, where it is now found fossil, extending into this region probably 

 during the Glacial Period, as it is no longer an inhabitant of the Mediterraneaa Sea. 



2. Mya a REN aria, Linnceus. Tab. XXVIII, fig. 2, a—f. 



Mya arenaria. Linn. Syst. Nat., ed. 12, p. 1112, No. 27, 1/67. 



— — J. Soiv. Min. Conch., t. 36-1, 1822. 



— — Gould. Inv. Massach., pp. 40 and 359, 1840. 



— — Nijsf. Coq. Foss. de Belg., p. 57, pi. 3, fig. 1, 1844. 

 _ _ Lov^n. Ind. Moll. Scand., p. 49, 1846. 



. — — Bekmj. Hist. New York Moll., p. 240, pi. 30, fig. 290. 



— — Midd. Malac. Rossica, p. 586, t. 20, figs. 1— 3, 1849. 



— LATAf J. Sow. Min. Conch., t. 81, 1815. 



— — TF. Smith. Strata Identif. Crag, fig. 9, 1816. 



— SUBOVATA. Woodio. Geol. of Norf., p. 43, t. 2, fig. 5, 1833. 



— SUBTEUNCATA. Id. Geol. of Norf., p. 43, t. 2, fig. 6. 



— MEKCENARIA. Smj. Journ. Acad. Nat. Sc, vol. ii, p. 313, fide Gmdd. 



— ACUTA. Say. Fide Gould, p. 40. 



Chama ARENARIA. Da Cosfu. Brit. Conch., p. 232. 



Dale. Hist, and Antiq. of Harwich, p. 29.3, t. 11, fig. 8, 1730. 



Spec. Char. Testa transversa, ovatct, elongatd, suhceqaUaterali^ crassd, rugosd ; antice 

 rotundatd ; postice subaciiminatd ; car dims dente deiiticulo later all acuta. 



Shell transverse, ovate, elongate, nearly equilateral, thick, and rough ; anterior side 

 rounded; posterior somewhat pointed; hinge tooth with a sharp lateral denticle. 

 Length, 2>\ inches. Height, 1\ inches. 

 Locality. Red Crag, Sutton, Bawdsey, Felixstow. 

 Mam. Crag, Bramerton, Bridlington. 

 Bracklesham {Dixon) . 



Recent, Britain, Scandinavia, and N. E. Coast of America. 



* The figure by Middendorff is not the short variety. 



