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857 



TERTIARY FAUNA OF FLORIDA 



FAMILY MYACIDvE. 

 (etuis MYA (Linnd) Lamarck. 

 < Mya Linne, Syst. Nat., Ed. x., p. 670, 1758. 

 ^ Hiatula (auct.) Schroter, Einl. Conch., ii., p. 599, 1784; Modeer, K. Vetensk. Handl., 



xiv., pp. 178, 182, 1793. 



= Mya Lam., Prodr., p. 83, 1799. Type Mya truncata L. 



Not Mya Modeer, op. fit., 1793, nor Mya Humphrey, Mus. Calonnianum, p. 59, 1797; 

 = Unio Ret/ius, 1788. 



Mya truncata Linne. 

 Mya truncata L., Syst. Nat., Ed. x., p. 670, 1758 ; Gould, Inv. Mass., p. 42, 1841 ; 



Jeffreys, Brit. Conch., Hi., p. 66, pi. 3, fig. I, 1865. 

 Mya ova/is (young) and Splu-nia Siuainsoni Turton, 1822. 

 Mya prcfdsa Gould, Proc. Host. Soc. Nat. Hist., iii., p. 215, 1850; Moll. U. S. Expl. 



Exp., p. 585, fig. 498. 



Pleistocene of the Arctic and boreal shores of the North Atlantic and 

 Bering Seas; at Portland, Maine; in the Leda clays of the St. Lawrence 

 River, at Quebec, Montreal, and Beauport; Polaris Bay, Greenland; Bessels; 

 and south to Massachusetts, and in Alaska to the Sitkan region. 



Mya arenaria Linne. 

 Mya arenaria L., Syst. Nat., Ed. x., p. 670, 1758 ; Gould, Inv. Mass., p. 40, 1841 ; 



Verrill, Inv. An. Vineyard Sound, p. 672, 1873 ; Dall, Bull. U. S. Nat. Mus., No. 



37, p. 70, pi. 49, fig. 9 ; pi. 55, fig. 2 ; pi. 69, fig. 2, 1889. 

 .]/)'<' incrci-iiaria Say, Journ. Acad. Nat. Sci. Phila., ii., p. 313, 1822. 

 Mya ai:nla Say, <>/>. fit., p. 313, 1822. 



Mya alba Agassi/:, Mem. Soc. Sci. Nat. Neuchatel, ii., p. I, pi. I, fig. 2-8, 1839. 

 Mya ][t-mt>liiltii Ncwcomb, Proc. Gala. Acad. Nat. Sci., v., p. 415, 1874. 

 Mya corftiili-nta Conrad, Fos. Medial Tert., p. 68, pi. 39, fig. i, 1845. 



Miocene of York River and Petersburg, Virginia, Burns ; of Gay Head, 

 Massachusetts, Dall ; Pleistocene of the Atlantic coast from Labrador to 

 South Carolina ; recent from Nova Scotia southward to North Carolina. 

 Introduced with seed oysters on the Pacific coast, and erroneously attributed 

 to Porto Rico (Agassiz). 



This well-known and widely distributed species was not originally a native 

 of the Pacific coast, where it was represented by a form which may be called 

 Mya intcrnifilia, which is intermediate in character between M. arenaria and 

 M. truncata, strongly recalling the glacial M. nddevallcnsis of Sweden. This 

 shell grows to a very large size on the Alaskan Peninsula and is very puzzling. 



