37&' TRANSACXrONS OF THE WAGNER FREE 



Eocene of Prairie Creek, Wilcox County, Ala., of the Sepulga River 

 and Matthews' Landing, Johnson and Aldrich. 



This species is a very remarkable form. The whorls are round and in- 

 flated, and the suture extremely deep, though not channelled. The umbilicus 

 is ample, and bounded at the left by a strong, elevated, rapidly enlarging rib, 

 which stands up from the base of the shell like the siphonal fasciole of a Nassa. 

 It is, however, solid, and terminates at the inner anterior part of the aperture 

 in a large, blunt, subtriangular callus. Above this rib the pillar is thin, sharp- 

 edged and emarginate, rising again to meet the thick callous deposit on the 

 body-whorl. The wall of the umbilicus is somewhat excavated. In the adult 

 shell this rib is relatively feeble, and transversely imbricated by coarse lines 

 of growth. In the young the surface is polished and smooth. The species 

 somewhat resembles A. recurva Aldrich, which is a larger shell, with the 

 umbilical rib higher up, with a shallow sulcus outside of it, and the sides of 

 the last whorl somewhat flattened anteriorly. 



Ampullina solidula n. s. 

 Plate 22, figure 31. 



Older Miocene of Ballast Point, Tampa Bay, in the Orthaulax bed, Dall. 



Shell small, thick, of about six nearly smooth whorls, marked only by 

 lines of growth; apex small, pointed; suture distinct; the whorls flattened for 

 a short distance in front of it, then amply rounded; base convex; umbilicus 

 moderate, deep, bounded by an elevated, narrow rib, inside of which the sur- 

 face is striated in harmony with the lines of growth; aperture rounded in front, ' 

 the pillar-lip thin, emarginate opposite the umbilicus, not reflected ; body with 

 little or no callus ; outer lip oblique, arched internally, thickened and slightly 

 expanded at the extreme edge. Alt. of shell 16; max. diam. 17 mm. 



The single specimen obtained is obviously different from any of the spe- 

 cies hitherto described. It is a much more solid shell than A. streptostoina of 

 the same size and has a different umbilicus. 



In taking leave of this group, it may be observed that De Gregorio refers 

 part of the species to Eiispira Agassiz, which is generally regarded as synony- 

 mous with Ampullina, and refers to it Neptiinea enterogranuna Gabb. The 

 latter, from the figures, is a siphonostomate shell, and it seems singular to find 

 it referred to a genus like Natica. 



The group has been so generally regarded as of generic rank that I have 

 left it so with a query, but I am tolerably confident it should be reduced to the 

 rank of a subgenus with the others. 



Subgenus Lacunaria Conrad. 

 Lacunaria Conrad, Am. Journ. Conch, ii. p. 77, 1866. Not of Dall, 1884. 



This group, while obviously related to Ampullina, differs in the absence of 

 callus on the base, by the acute spire, tendency to sculptural striation of the 



