TRANSACTIONS OF WAGNER 

 1 140 



TERTIARY FAUNA OF FLORIDA 



Section Epilepton Dall. Type Leptoii Clarkice Jeffreys. 



Shell much as in Neolepton; hinge with a simple posterior and a hooked 

 anterior lamella in each valve, not concentrated, the resilium in an oblique 

 posterior furrow. 



Lepton glahnim Fischer, from deep water in the Bay of Biscay, also has 

 the typical hinge of this section, which verges on that of Erycina. 



Section Plaiiikellia Cossmann. Type Erycina radiolata Lam. 



Shell recalling Lepton but with radial sculpture ; hinge with a central 

 resilium between two diverging lamellae in the left, which are received between 

 paired lamellae in the right valve ; there is no " hook" or cardinal in either 

 valve. 



I was enabled to study the hinge in specimens kindly sent by M. Cossmann. 

 It differs from the hinge of Lepton s. s. chiefly in the absence of the cardinal 

 hook in the left valve. There are several species in the Parisian Eocene. 



The genus Lepton is not represented in our Tertiaries as far as explored. 

 Only one species belonging to the genus as restricted is known from the 

 Atlantic coast recent fauna. Lepton alabamensis Aldrich proves to be a Spor- 

 tella; L. mactroides and fabagella Conrad are referable to Bornia and Kellia. 



The genus has been considered here to make the discussion of the Lepto- 

 nacea more complete and because the manuals are, as a rule, very defective in 

 their treatment of this puzzling group. 



Genus ERYCINA Lamarck. 

 <^Scacchia Philippi, Moll. Sicil., ii., p. 27, 1844; ist sp. TcUina ellipHca Scacchi. Phil. 

 = Erycina Recluz, Revue Zool., vii., pp. 291, 325, 1844. Type E. pellucida Lam., Ann. 



du Mus., vi., p. 413 ; Deshayes, An. s. Vert. has. Paris, pi. 6, figs. 19-21. 

 = Erycina Cossmann, Cat. Illus., ii., p. 50, 1887; Fischer, Man. de Conchyl., p. 1025, 



1887. 

 Not Erycina Philippi, Moll. Sicil., i., p. 12, 1836, type E. Renieri Brown {— Abra) ; nor 



Erycina Brown, Zool. Textb., p. 461, 1833, type E. striata Brown, pi. 90, fig. 21 



(=: Atactodea) . 

 yScacchia Philippi, Moll. Sicil., ii., p. 27, 1844; ist sp. Teltina clUptica Scacchi, Phil., 



op. cit., pi. 14, fig. 8. 

 = Neccromya Gabb, Trans. Am. Phil. Soc, xv., p. 247, 1873 ; Proc. Acad. Nat. Sci. Phila. 



for 1872, p. 274. Type N. quadrata Gabb, loc. cit., pi. 10, figs. 4, 4", 4b, 1872. 



The genus Erycina as instituted by Lamarck was extremely heterogeneous, 

 the first species being a Cyrena, the third a Corbula, the fourth a Tcllina. the 



