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IO61 



TERTIARY FAUNA OF FLORIDA 



A single valve of this species was obtained by Messrs. Burns and Harris. 

 It is readily discriminated from the other American species by its CalUsta- 

 like form and very fine, even radial sculpture. 



Petricola (Petricolaria) pholadiformis Lamarck. 



Petricola pholadiformis Lam., An. s. Vert., v., p. 505, 1818; Conrad, Am. Mar. Conch., 

 P- Z7, pl- 7, fig- 3. 1831 ; Say, Am. Conch., pi. 60, fig. r, 1834; Gould, Inv. Mass., 

 p. 63, 1841 ; Sowerby, Thes. Conch., ii., p. 771, pl. 166, fig. I, 1854; Dall, Bull. U. S. 

 Nat. Mus., No. 37, p. 58, pl. 59, fig, 15, pl. 64, fig. 140a, 1889. 



Petricola fornicata Say, Journ. Acad. Nat. Sci. Phila., ii., p. 319, 1822. 



Pleistocene of Simmons Bluff, South Carolina ; Burns. Living from 

 Prince Edward Island south to St. Thomas, West Indies ; Greytown, Nica- 

 ragua, and other portions of the Antillean region. Var. dactylus Sby. Post- 

 pliocene of South Carolina according to Holmes. 



It is probable that the P. dactylus Sowerby, though closely related to P. 

 pholadiformis, may be regarded as specifically distinct. Both forms occur 

 together from Maine to Florida, but on the South American coast the typical 

 pholadiformis does not seem to have been found, though several other varieties, 

 some of which have been named, have been reported by observers near the 

 southern extreme of South America in what was formerly Patagonia. 



The curious little shell named in 1872 by Verrill Gastranella tuinida is 

 certainly a Petricolaria, and I suspect it to be the young of P. dactylus, which 

 has when very young and fresh a purplish tinge on the umbones in some 

 individuals. The hinge is precisely the same in both. Carpenter similarly 

 took the nepionic young of P. denticulata Sowerby for a Psephis and described 

 it under the specific name of tellimyalis. This was the more excusable since 

 the fry are brightly colored with orange and purple, while the adult and 

 adolescent stages of the Petricolaria are pure white. I have a series showing 

 the latter with its purple umbones strongly contrasting with the white valves, 

 but this condition lasts only a short time, the color fading entirely out in most 

 specimens before they attain full growth. 



Family COOPERELLIDyE. 

 Genus COOPERELLA Cpr. (em). 



> Oedalia Carpenter, Rep. Brit. Assoc, for 1863, pp. 611, 639. Type named, Oe. sub- 

 diaphana Cpr., p. 639, Aug., 1864; Journ. de Conchyl., xii., p. 134, Apr., 1865 (same 

 type) ; Smiths. Misc. Coll., No. 252, Moll. W. N. Am., pp. 97, 125, 302, Dec, 1872. 



