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1263 



TERTIARY FAUNA OF FLORIDA 



Cytherea convexa Conrad (not Say), Journ. Acad. Nat. Sci. Phila., vi., p. 261, 1831; 



Gould, Inv. Mass., p. 84, pi. iii., fig. 49, 1841 ; De Kay, Zool. N. Y., v., p. 216, pi. 



xxvii., fig. 279, 1843; Sowerby, Thes. Conch., ii., p. 638, pi. cxxxii., fig. 119, 1851; 



Mighels, Boston Journ. Nat. Hist, iv., p. 320, 1843, and many other authors. 

 Cytherea Sayana Conrad, ex parte, Am. Journ. Sci., xxiii., p. 345, 1833 > Ravenel, Cat. 



Coll., p. 4, 1834. 

 Dione convexa Deshayes, Cat. Conch., Brit. Mus., p. 71, 1853; Reeve, Conch. Icon., xiv., 



pi. x., fig. 40, 1863. 

 Callista convexa H. and A. Adams, Gen. Rec. Moll., ii., p. 425, 1857; Verrill, Inv. An. 



Vineyard Sd., p. 681, 1873. 

 Callista Sayana Tryon, Am. Mar. Conch., p. 160, pi. xxix., fig. 398, 1873 ; Verrill, Inv. 



An. Vineyard Sd., p. 682, 1873. 

 Cytherea Sayii Perkins, Proc. Bost. Soc. Nat. Hist., xiii., p. 147, 1869. 



Miocene of the York River, Virginia, at numerous localities, and of Shell 

 Branch, near Darlington, South Carolina; Pleistocene of Wailes Bluff, near 

 Cornfield Harbor, St. Mary's County, Maryland ; living from Prince Edward's 

 Island south to Cape Hatteras, North Carolina, in moderate depths of water. 



This is a cold-water species and is missing from the warmer Pliocene, 

 where C. Sayana survives, the latter bearing to the former in Tertiary time 

 such a relation as the C. aresta of Porto Rico does to the existing C. mor- 

 rhuana. Some writers in allotting names have endeavored to show that the 

 name Sayana should be preserved for the recent shell on the ground that Con- 

 rad so applied it. It is true that he did so apply it as an afterthought. But it 

 was proposed by him originally to replace the preoccupied name of a fossil 

 species described by Say, and the fact remains that it can be properly applied 

 to nothing else. That the fossil and recent forms were at one time confounded 

 has nothing to do with the question of nomenclature, since the name convexa, 

 which Sayana was to replace, was originally applied to the fossil form, without 

 any reference to the recent one. Neither Conrad nor any other writer can alter 

 this fact, which binds the application of the substitute irrevocably to the fossil. 

 The first name subsequently applied to the recent shell as such is that of 

 Linsley as identified from the types by Gould, which must be and is therefore 

 here adopted. 



There is little difficulty in discriminating between adult C. Sayana and the 

 recent shells, unless in the case of some specimens of the upper Miocene, 

 which I believe to be a mutation of Sayana, but which vary (as might be ex- 

 pected, theoretically) towards the type which is later fixed in the recent form. 

 As some students might regard these as conspecific with morrhuana I note 



