672 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



fathoms or more. In Casco Bay it is extremely abundant in rocky, cav- 

 ernous pools, among the ledges at low-water mark, and mostly attached 

 by a byssas, associated with Modiola modiolus. I also found specimens 

 in 10 to 15 fathoms, perforating recent and sound shells of Cyprina 

 Islandica. In the Gulf of Saint Lawrence, near Anticosti Island, where 

 limestone abounds, I have found it burrowing in the limestone in large 

 numbers. South of Cape Cod it is far less abundant, though not un- 

 common in Long Island Sound. Yar. distorta (Say) is common from 

 Fort Macon to Georgia, and is possibly a distinct species. Fossil in the 

 Post-Pliocene of Maine, 'New Brunswick, Canada, Anticosti, Labrador, 

 Scandinavia, and Great Britain ; in the Coralline and Bed Crags of Eng- 

 land, etc. Yar. distorta is found in the Miocene of Maryland. 



Mya ARENARIA Linne. Plate X.XYI, fig. 179. (pp. 357, 163.) 



Systema Naturae, ed. sii, p. 1112, 1767 ; Gould, Invert., ed. i, pp. 40, 359 ; ed. ii, j). 

 55, fig. 375. Mya mercenaria and M. acuta Say, Journal Acad. Nat. Sci., Phila- 

 delphia, vol. ii, p. 313, 1822. 



South Carolina to the Arctic Ocean ; northern coasts of Europe, south 

 to England and France ; northeastern coast of Asia, south to China and 

 Japan (Hakodadi). Sitka (Middendorff). South Carolina (Gibbs). Fort 

 Macon, l^orth Carolina (Dr. Yarrow). Comparatively scarce south of 

 Cape Hatteras. Yery abundant from New Jersey northward, both in 

 brackish estuaries and on the open coasts. Particularly^ large and fine in 

 Long Island Sound (see p. 163). Casco Bay and Bay of Fundy, from 

 half- tide mark to 10 fathoms, those dredged being all young. Fossil in 

 the Post-Pliocene of Scandinavia, Greenland, Labrador, Canada, New 

 England, Yirginia, South Carolina, etc.; in the Red-Crag and all later 

 formations in Great Britain ; and in the Miocene of Yirginia. 



ConBULA CONTRACTA Say. Plate XXYII, fig. 191. (p. 118.) 



Journal Acad. Nat. Sciences, Philadelphia, vol. ii, p. 312, 1822; Gould, Invert., 

 ed. i, p. 43, fig. 37 ; ed. ii, p. 60, fig. 377. 



Cape Cod to Florida. Common, living, in Yineyard Sound and Buz- 

 zard's Bay, in 5 to 19 fathoms ; Long Island Sound, near New Haven, 

 not uncommon in shallow water. Georgia (Couper). Fossil in the 

 Post-Pliocene of Yirginia, North and South Carolina ; and in the Plio- 

 cene of South Carolina. A closely related species occurs in the Mio- 

 cene of Maryland. 



Lyonsia hyalina Conrad. Plate XXYII, fig. 191. (p. 358.) 



American Marino Conchology, p. 51, Plato 11, fig. 2, 1831 ; Gould, Invert., ed. ii, p. 



64, fig. 380. Mya hyalina Conrad, Jour. Acad. Nat. Sci., Philadelphia, vol. vi, 



p. 261, Plato 11, fig. 12, 1831. Osteodesma hyalina Couthouy, Boston Jour. Nat. 



Hist., vol. ii, p. 166, 1839 ; Gould, Invert., ed. i, p. 46, fig. 31. 



Florida to Gulf of Saint Lawrence. Common in Long Island Sound, 



Buzzard's Bay, Yineyard Sound, ]\[assachusetts Bay, Casco Bay, and 



Bay of Fundy ; low-water mark to 30 fathoms j Beaufort, North Carolina 



(Coues). 



