TRANSACTIONS OF WAGNER 

 1126 



TERTIARY FAUNA OF FLORIDA 



only in part. Deshayes describes the ligament as external, seated on a nymph, 

 but says nothing of the resilium ; Conrad mentions the cartilage pit, but mis- 

 takes the nymphse for lateral teeth and says nothing of an external ligament. 

 The type of Fabella undoubtedly possessed both, somewhat more strongly 

 developed than in the French fossil. The dentition of the two is identical, and 

 after a careful study of several species of Sportella, including the typical species, 

 for which I am indebted to the courtesy of M. Cossmann, I am of the opinion 

 that Sportella also possessed an internal resilium. The scar is faint and if at 

 all worn not visible in S. dubia, but in S. gibbosula Deshayes I find it well 

 defined, though in any case less impressed than in the American species. The 

 surface of S. dubia is sculptured with faint, almost microscopic radial scratches, 

 traces of which may be found in most of the species, though obsolete in some 

 of them. The pallial area of the inner surface of the shell is sometimes punc- 

 tate. All these features tend to unite it with the other Leptonacea. Myllita 

 has a similar duplex ligament; some of the Kellias and Cyainium have both 

 separately developed. The differences between the American Fabella and the 

 European Sportella are trifling and only of degree, but for those who prefer 

 very minute subdivision in such groups I suppose the name Fabella might be 

 kept in a sectional sense for the American species. 



The earliest Sportella recorded in our Tertiary is the Fabella oblonga 

 Aldrich (Bull. Am. Pal., ii., No. 8, p. 182, pi. 5, fig. 20, 1897; Harris, Bull. 

 Am. Pal., ii., No. 9, p. 250, pi. 2, figs. 7-8, 1897) from the Lignitic or Chicka- 

 sawan at Wood's Bluff, Alabama. The Claibornian offers S. Gregorioi Coss- 

 mann (Notes Compl., p. ii, pi. i, figs. 11-12, 1894, Aid. Bull. Am. Pal., No. 

 8, p. 173, pi. 5, fig. 4, 1897) and Aldrich's Lepton? alabamense (op. cit., p. 182, 

 pi. 5, fig. 9) has, though obscure, the aspect of Sportella. The hinge is cer- 

 tainly not that of Lepton. I have examined the type specimen. It is Clai- 

 bornian. 



Curiously enough the Upper Eocene and the Oligocene up to the Oak- 

 Grove sands have not afforded any species of Sportella so far, unless some of 

 the species we have included under Montacuta would more properly find a place 

 here. In the sands, however, the genus seems to reappear as follows : 



Sportella obolus n. sp. 

 PLATE 44, FIGURE 18. 



Oak Grove sands, Santa Rosa County, Florida ; Burns. 



Shell small, solid, subcircular and flatfish ; interior polished, the cicatrices 



