TRANSACTIONS OF WAGNER 



TERTIARY FAUNA OF FLORIDA 



Gemma gemma variety purpurea Lea. 

 Plate 24, Figures 2, 4, 4b. 

 Cyrena purpurea Lea, Am. Journ. Sci., xli., p. 106, pi. i., fig. i, 1842. 

 fVenus manhattanensis Prime, in Jay's Cat., 4th ed., Suppl., p. 466, 1852 (name only) ; 



Ann. Lye. Nat. Hist. N. Y., vii., p. 482, 1862. 

 Parastarte conccntrica Dall (name only). Bull. U. S. Nat. Mus. No. 37, p. 48, 1889. 

 Gemma purpurea Dall, Trans. Wagner Inst., iii., p. 919, pi. xxiv., figs. 2, 4, 4b, 1898. 

 Gemma gemma subsp. purpurea Dall, Journ. Conch. (Manchester), x.. No. 8, p. 241, 1902. 

 Tottenia manhattanensis Verrill, Inv. An. Vineyard Sd., p. 682, 1873. 



Pleistocene of the Texas coast at Corpus Christi ; living from the south 

 side of Cape Cod south to the Bahamas and west to the coast of Texas. 



The type specimens of H. C. Lea are in the National Museum and are 

 certainly young shells of the southern inflated, strongly sculptured form of 

 Gemma. The name therefore has twenty years' precedence of manhattanensis. 

 The true place of the latter is somewhat doubtful because the figure given by 

 Prime is very inaccurate, and the specimens I have seen labelled manhattanensis 

 by Stimpson and others are certainly only pale forms of G. gemma. But if we 

 disregard the details of the figure and attend merely to Prime's diagnosis we 

 find manhattanensis dififerentiated from gemma by being " smaller, more tri- 

 angular, less full, less elongated," and white instead of purple. Now adult 

 purpurea is larger and more inflated than adult gemma, but Prime's specimens 

 were young, only three millimetres long, while the adult reaches 5.25. I find 

 specimens of purpurea three millimetres long are sometimes more coinpressed 

 than the adult gemma; they are generally paler and often white. The coarse 

 and regular striae also point towards purpurea. It seems likely that Prime's 

 species was founded on young, whitish specimens of G. purpurea and after- 

 wards became confused by collectors with the white mutation of G. gemma. 

 In either case the name falls into synonymy. 



Genus PARASTABTB Conrad. 

 Parastarte Conrad, Proc. Acad. Nat. Sci. Phila. for 1862, p. 288, 1862, Astarte triquetra 



Conrad ; Dall, Proc. U. S. Nat. Mus., vi., p. 339, 1883 ; Bull. U. S. Nat. Mus. No. 37, 



p. 48, 1889. 

 Callkistronia Dall, Science, ii., p. 447, Sept. 28, 1883. 

 Goodallia Tryon, Syst. Conch., iii., p. 227, 1884 ; not of Turton, 1822. 



Shell small, heavy, trigonal, with elevated and prominent beaks, equilateral, 

 equivalve, with a short ligament and large lunule ; surface smooth, with a 

 vernicose periostracum and purple and white coloration ; inner margins crenate ; 



