88 Bulletin 15 398 



The foreign analogue is found in the Belgian Oligocene 

 (Nyst, Coq. et poly, foss., p. 49). 



Miocene. 



SOLEN ENSIS Linn. 



Heilprin (Contr. Tert. Geol., p. 99) considers that this species 

 and kS. ensifo7'mis Con. (Foss. Med. Tert., p. 76, pi. 43, fig. 8), of 

 the American Miocene, are identical. Var. B. Lnik. of S. ensis 

 is reported by Nyst from the Belgian Oligocene (Coq. et pol}'. 

 foss., p. 47). 



SAXICAVA ARTICA Linn. 

 Syst. Nat. Ed., xii, 1767, p. 11 13. 



This species is found in the Oligocene of Germany, Speyer 

 (Sollingen, p. 294, ^bicristata Sandb.) and Koenen (Mit. Olig. 

 N. D. Pal., 16, p. 266); of Mainz, Lepsius (Mainz Beck.); and of 

 Bordeaux, Benoist (Cat., p. 19). 



It occurs in the American Miocene, Pliocene, Pleistocene, and 

 living in temperate seas. Mayer {Proc. Acad. Nat. Sd., Phila., 

 1884, p. 108) places S. Jeurre7isis Desh., from the Oligocene of 

 Etampes, and S. bilmcata Con. as synonyms of ^. artica. 



Correlations of European Oligocene Beds with Those of the 

 Southern States. 



Conrad'' s correlation. Conrad, in 1866,* referred the Vicks- 

 burg limestone to the Oligocene beds of Bey rich, both series being 

 charadterized by a peculiar fauna, intermediate between Eocene 

 and Miocene. In 1875,! Conrad states that he regards the Jack- 

 son as older Oligocene, and the Vicksburg as newer Oligocene. 

 This confirms his earlier view, in 1846, that the faunal affinities 

 of the Vicksburg group were stronger with the species of Dax and 

 the Bordelais than with the Eocene species of the Paris basin. 



The correlation of Conrad was, however, not generally ac- 

 cepted, and the Vicksburg was classed as Upper Eocene. The 

 Chattahoochee series was placed in the Eower Miocene. 



* Check list foss. N. A., Smith. Miss. Coll., No. 200. 

 t GeoL N. Carolina, vol. i, 1875, Appendix A, p. 25. 



