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TERTIARY FAUNA OF FLORIDA "^ 



Pleistocene of the Aleutian Islands and bowlder clay of southeastern Alaska 

 near Juneau; recent from the Kamchatkan coast at Avatcha Bay, eastward 

 through the Aleutians, the southern part of Bering Sea, and southeastward 

 to Sitka, Alaska. 



This fine form is not to be confounded with 5". grbnlandicus var. pro- 

 tractus, which occurs wherever 5. gronlandicus extends, though rare. The 

 present shell far exceeds 5". grdnlaiidicus in size and is restricted to the range 

 above mentioned. 



I have already mentioned that Serripes bulla Gabb (Santo Domingo, 1873) 

 should be referred to Lcsvicardium; and Cardium centMosum Cpr., which 

 has been referred to Serripes by some authors, is a Protocardia. In this group 

 the teeth are often strongly developed in young specimens, but the cardinals, 

 and much more rarely the laterals, become more or less obsolete in the adult 

 or senile specimens. 



Genus PROTOCARDIA Beyrich. 



The Eocene species of Protocardia known in our Tertiary are as follows : 

 P. curta Conrad (1870, not Cardium curtum Meek and Hayden, 1861), from 

 the Eocene marls of New Jersey, a doubtful species founded on an internal 

 cast which does not admit of an exact determination of the species ; P. lenis 

 Conrad (1855, unfigured, + P. virginiana Conrad, 1864; not P. lenis var. 

 Harris, 1897), from the Eocene of Pamunkey River, Virginia; P. Harrisi Dall 

 (1900, ^ P. virginiana Harris, Proc. Acad. Nat. Sci. Phila. for 1896, p. 475, 

 pi. 20, figs. 7, 8), from the Chickasawan of Alabama ; P. Nicoleti Conrad ( 1841, 

 + P. lima Conrad, 1865, which is merely the shell retaining its posterior tu- 

 bercles which are frequently lost), Jacksonian, and P. virginiana Conrad (1864, 

 = P. lenis Conrad, 1855), from the Eocene of Virginia. 



The young of P. diversa shows the interspaces of the ribs crossed by 

 somewhat irregular elevated lamellae (often worn away) ; the young of 

 P. Nicoleti has, when perfect, strawberry-shaped pustules on top of the ribs, 

 the channels smooth or nearly so ; specimens of P. Harrisi Dall show minute 

 tubercles on the anterior sides of the ribs in the channels, but the tops of the 

 ribs are smooth ; this species is more quadrate, with less produced terminal 

 margins. It is a smaller shell and more glistening and with more conspicuous 

 anterior sculpture than the others. Sundry large specimens in somewhat imper- 

 fect condition, from Naheola Bluff, are in the National Collection. They may 

 be an undescribed species, or possibly the adults of P. Harrisi. 



The Oligocene has the well-known P. diversa Conrad, 1848, for the more 



