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TERTIARY FAUNA OF FLORIDA 



Dosinia Aoridana Conrad, Am. Journ. Conch., ii., p. 280, pi. xv., fig. 4, 1866. 

 Dosinia elegans Dall, Rep. Moll. Porto Rico, p. 486, 1901, not of Born. 



Pleistocene of Cuba, Orbigny ; living in the Florida Keys (Conrad), 

 Martinique, Porto Rico, Aspinwall, or Colon, and southward to Rio de Janeiro. 



The earlv writers, misled by the similarity of the species, confounded under 

 the name concentrica a number of Dosinias. The first to give an original figure 

 upon which the name may depend was Born, who gave an erroneous synonymy 

 but an excellent figure of the present shell. Orbigny, later, discriminated be- 

 tween D. elegans Conrad (Lister, pi. cclxxxviii., fig. 124) and D. concentrica, 

 but, regarding elegans as the original concentrica, gave a new name to the shell 

 which Philippi erroneously ascribed to Patagonia, but which agrees with Born's 

 figure^ which elegans does not. 



The confusion between the species has been so general that it is unsafe to 

 cite habitats from the literature, but we have it from Colon, on the Isthmus of 

 Darien, and an immature specimen is said by Conrad to have come from the 

 Florida Keys, and was named by him D. floridana. It is somewhat smaller than 

 D. elegans, more convex, and the sculpture is less persistent on the middle and 

 base of the shell, while the lunule is much larger. 



Dosima (Dosinidia) ponderosa Gray. 

 Artemis ponderosa Gray, Analyst, viii., p. 309, 1838; Reeve, Conch. Iconica, Artemis, pi. 



i., fig. 4, 1850; Hanley, Descr. Cat. Rec. Sh., p. 109, pi. xix., fig. 38, 1843; Sowerby, 



Thes. Conch., ii., p. 656, pi. cxl., fig. 2, 1852. 

 ? Artemis distans Sowerby, Thes. Conch., ii., p. 655, pi. cxl., fig. 3, 1852 (young shell). 

 Cytherea {Artemis) gigantea (Sowerby MS.) Philippi, Abb. Beschr. n. Conchyl., p. 33, 



pi. vi., fig. I, 1847. 

 Venus cycloides Orbigny, Voy. Am. Merid., p. 562, 1847; B. M. Cat. Orb. Moll., p. 67, 



No. 596. 

 Dosinia ponderosa Deshayes, Cat. Conch. Brit. Mus., p. 7, 1853 ; Carpenter, Maz. Cat., 



p. 60, 1857. 



Pleistocene of San Diego and San Pedro, California, Hemphill ; living from 

 San Ignacio lagoon, west coast of Lower California, to Payta, Peru. 



This is the finest species of the genus, unless the D. grandis Nelson (Trans. 

 Conn. Acad. Sci., ii., p. 201, 1870) from the Tertiary of Peru, which is un- 

 figured, may perhaps exceed it. There are about a dozen other species of the 

 Pacific coast Tertiary which have been referred to this genus, but I have not 

 access to material which would enable me to discuss their relations. 



The only other species of this genus which has been described from the 



