TRANSACTIONS OF WAGNER 

 966 



TERTIARY FAUNA OF FLORIDA 



any data or specimens to elucidate the standing of the brackish-water fossil, 

 Oncophora, said by Tryon to be allied to Donax, nor of the Jurassic genus 

 Delia De Loriol, 1891 (not of Robineau Desvoidy, 1830), which is said to 

 belong to this family. 



Donax funerata Conrad. 

 Donax funerata Conrad, Proc. Acad. Nat. Sci. Phila., iii., p. 292, 1848; Journ. Acad. Nat. 



Sci. Phila., 2d Ser., i., p. 123, pi. 13, fig. 9, 1848; S. I. Eoc. Checkl., p. 28, 1866. 

 Egeria funerata Conrad, Am. Journ. Conch., i., p. 5, 1865. 



Four miles northwest of Vicksburg, Mississippi, Conrad ; in the Vicks- 

 burgian Oligocene at Vicksburg, C. W. Johnson. 



This is the earliest true Donax yet identified from our Tertiaries. 



Donax sequalis Gabb. 

 Donax aqualis Gabb, Geol. St. Dom., p. 249, 1873. 



Later Tertiary of Santo Domingo, Gabb ; Bowden beds Oligocene at Bow- 

 den, Jamaica, Henderson and Simpson. 



Small, faintly striated, and nearly equilaterally triangular, and moderately 

 convex. , 



Donax chipolana n. sp. 

 PLATE 44, FIGURE 20. 



Oligocene of the Chipola River, Calhoun County, Florida ; Burns. 



Shell small, thin, smooth, with faint radial striation behind ; anterior end 

 smaller, produced, rather bluntly rounded at the end ; anterior dorsal margin 

 rectilinear, basal margin nearly straight ; posterior end wider, short, not 

 carinate or markedly truncate but bluntly rounded ; right valve with well- 

 marked sockets for the laterals, the anterior one longer ; ventral edge finely 

 serrate, the serrations shorter below the beak ; pallial sinus subquadrate, hori- 

 zontal, ventral portion largely confluent with the pallial line. Lon. 9.5, alt. 5.5, 

 diam. 3 mm. 



A single valve was obtained by Burns which has been bored by a gastropod. 

 The shell is remarkably fresh and still retains traces of purple coloration along 

 the hinge-line. With it was another valve of smaller size which may repre- 

 sent a distinct species or an extreme variation of the preceding. The umbo is 

 more posterior, the anterior end more pointed, and the posterior end shorter 

 and more rounded. In view of the variability of species of this group I prefer, 

 until more material comes to hand, to regard it as a variety curtula of the D. 

 chipolana. 



