672 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



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

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

 by a byssus, associated with Modioli modiolus. I also found specimens 

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

 Islandica. In the Gulf of Saint Lawrence, near Auticosti 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, Auticosti, Labrador, 

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

 land, etc. A"ar. distorta is found in the Miocene of Maryland. 



Mya ARENARIA Linue. Plate XXYI, fig. 179. (pp. 357, 463.) 



Systema Natur;i>, ed. xii, p. 1112, 1767 ; Gould, Invert., ed. i, pp. 40, 3.59 ; ed. ii, y>- 

 55, fig. 375. 3Iya merveuaria and M. acuta Say, Jourual Acad. Nat. Sci., Phila- 

 delpMa, 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, North 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. 463). Casco Bay and Bay of Fundy, from 



half-tide mark to 40 fathoms, those dredged being all young. Fossil iu 



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



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



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



CoRBULA CONTRACTA Say. Plate XXYII, fig. 101. (p. 418.) 



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 Yiueyard 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-Plioceue 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. 194. (p. 358.) 



* American Marine Couchology, p. 51, Plate 11, fig. 2, 1831 ; Gould, Invert., ed. ii, p. 

 64, fig. 380. 3Ii/a hyalina Conrad, .Jour. Acad. Nat. Sci., Philadelphia, vol. vi, 

 p. 261, Plate 11, fig. 12, 1831. (Meodesma 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, Yiueyard Sound, Massachusetts Bay, Casco Bay, and 

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



(Coue«). 



