BIVALVIA. 279 
remarkable that the specimens of Panopea Norvegica found at this locality, 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 Mediterranean Sea. 
2. Mya ARENARIA, Linneus. Tab. XXVIII, fig. 2, aH 
Mya arenaria. Linn. Syst. Nat., ed. 12, p. 1112, No. 27, 1767. 
— _— J. Sow. Min. Conch., t. 364, 1822. 
— _ Gould. Inv. Massach., pp. 40 and 359, 1840. 
_ — Nyst. Coq. Foss. de Belg., p. 57, pl. 3, fig. 1, 1844. 
— = Lovén. Ind. Moll. Seand., p. 49, 1846. 
— Dekay. Uist. New York Moll., p. 240, pl. 30, fig. 290. 
— — Midd. Malac. Rossica, p. 586, t. 20, figs. 1—3, 1849. 
— Lata. J. Sow. Min. Conch., t. 81, 1815. 
— W. Smith. Strata Identif. Crag, fig. 9, 1816. 
— supovaTa. Woodw. Geol. of Norf., p. 43, t. 2, fig. 5, 1833. 
— subprruncata. Id. Geol. of Norf., p. 43, t. 2, fig. 6. 
— MERCENARTA. Say. Journ. Acad. Nat. Sc., vol. ii, p. 313, fide Gould. 
— acuta. Say. Fide Gould, p. 40. 
CHAMA ARENARIA. Da Costa. Brit. Conch., p. 232. 
Dale. Hist. and Antig. of Harwich, p. 293, t. 11, fig. 8, 1730. 
Spec. Char. Testa transversd, ovatd, elongata, subequilaterali, crassd, rugosa ; antice 
rotundatd ; postice subacuminatd ; cardinis dente denticulo laterali acuto. 
Shell transverse, ovate, elongate, nearly equilateral, thick, and rough; anterior side 
rounded ; posterior somewhat pointed; hinge tooth with a sharp lateral denticle. 
Length, 3% inches. Height, 25 inches. 
Locality. Red Crag, Sutton, Bawdsey, Felixstow. 
Mam. Crag, Bramerton, Bridlington. 
Bracklesham (Dizon). 
Recent, Britain, Scandinavia, and N. E. Coast of America. 
* The figure by Middendorff is not the short variety. 
