TRANSACTIONS OF WAGNER 



TERTIARY FAUNA OF FLORIDA 



of northeast and northwest America, and the so-called variety polygona (T. 

 trisinuata Orbigny) Jeffreys, which is distributed very widely. It must be con- 

 fessed, however, that the mutations of the species are considerable enough to 

 afford some excuse for the view of them taken by Jeffreys. 



Thyasira G-ouldii Philippi. 



Lucina ftexuosa Gould, Inv. Mass., p. 72, fig. 52, 1841 ; not of Montagu, 1803. 

 Axinus Gouldii Philippi, Zeitschr. Malak., 1845, p. 75. 



Tyatira liyalina Beck (MS.?), 1847, fide Morch, in Rink's Greenland, 1857, p. 19. 

 Thyasira Gouldii Stimpson, Sh. of N. Eng., p. 17, 1851 ; Morch, in Rink's Greenland, p. 



19, 1857; Arctic Man., p. 131, 1875; Dall, Synopsis Lucinacea, p. 786, 1901. 

 Cryptodon Gouldii Verrill, Inv. An. Vineyard Sound, p. 686, pi. xxix., fig. 213, 1873 ; 



Dall, Bull. U. S. Nat. Mus., No. 37, p. 50, pi. Iviii., fig. 2, 1889. 

 Axinus Hexuosus Montagu var. fide Jeffreys. 



Pliocene of Dead Man's Island, San Pedro, California; Pleistocene of 

 northeastern North America and Bering Sea ; recent from Hekla Harbor, 

 Greenland, south to Stonington, Connecticut, in five to four hundred fathoms ; 

 Bering Sea and southward to Korea on the west, and Queen Charlotte Islands 

 on the east, of the North Pacific. 



sC Thyasira bisecta Conrad. 



Venus bisecta Conrad, Geol. Wilkes Expl. Exp., p. 724, pi. xvii., fig. 10, 1849. 

 Cyprina bisecta Conrad, Am. Journ. Conch., i., p. 153, 1865; Eocene Checklist, S. I., p. 



6, No. 160, 1866. 



Thyatira? bisecta Meek, Miocene Checklist, S. I., p. 8, No. 247, 1864. 

 Conchocele disjuncta Gabb, Pal. Cal., ii., p. 28, pi. vii., fig. 48a-b, 1866; p. 99, 1869. 

 Conchocele bisecta Gabb, Pal. Cal., ii., p. 99, 1869. 

 Thyasira bisecta Dall, Synopsis of Lucinacea, p. 817, pis. xl., xlii., figs. 5, 8, 1901. 



Miocene of Astoria, Oregon, Dana ; Pliocene of San Pedro, California, 

 Dall; living in Puget Sound, O. B. Johnson and United States Fish Commis- 

 sion. 



This remarkable species is found in the Pliocene (not the Post-Pliocene, as 

 stated by Gabb) of Dead Man's Island off San Pedro, but is entirely absent 

 from the Pleistocene of San Pedro Hill on the mainland. The edges of the 

 rather delicate nymphs upon which the ligament was seated were mistaken by 

 Gabb for lateral teeth. I have been unable to detect any differences of sys- 

 tematic value between the Miocene fossils and the recent shells dredged by the 

 Fish Commission. 



