INSTITUTE OF SCIENCE, PHILADELPHIA. 415 



Meyer may be a synonym ; and T. Iceve Meyer, of which the author reports a 

 variety vicksbnrgense in the Vicksburgian. 



The Miocene and Pliocene species will now be described, and, as the last 

 species cited under the preceding section was one which up to the latest 

 moment of attaining maturity might seem to belong in Solariorbis, so ihe 

 first species here described will be one which barely misses establishing itself 

 as a Pseudorotella. 



Teinostoma microforatis n. s. 

 Plate 23, figures 9, 10. 



Older Miocene of the Chipola beds, Calhoun Co., Florida, Burns. 



Shell large for the genus, with four or five whorls; surface polished, 

 sculptured ; spire flattened ; upper surface of the whorl with two spiral sub- 

 equal ribs, one close to and in front of the suture, the other near the periphery 

 and having the suture laid upon it ; surface between these ribs slightly convex, 

 sculptured with numerous fine sharp spiral grooves crossed by numerous 

 rather distant impressed lines of growth, producing a punctate effect at the 

 intersections; periphery rounded, base moderately convex, with a sculpture 

 similar to that of the spire, but stronger, increasing in strength and in the 

 width of the interspaces toward the umbilical area, which is nearly smooth and 

 evenly rounded ; aperture rounded, oblique, angulated at the upper commis- 

 sure and by the rib; pillar thin and short, at its base supported by a triangular 

 thickening due to a stout projecting umbilical rib which overhangs and 

 screens the small perforate umbilicus. Alt. of shell 2.3 ; max. diam. 4.7; 

 min. diam. 3.7 mm. 



The nucleus of this handsome little shell is swollen and prominent, almost 

 as if it might be sinistral, and immersed in the spire. There is no callus on 

 the pillar or umbilicus, and, viewed vertically from below, the shell seems 

 imperforate, but under the shadow of the thick rounded umbilical rib there is 

 a small perforate umbilicus, essentially as in Leiuorliyncliia. 



The species is nearest T. quadrangiilare Meyer, but has no angle at the 

 periphery of the base, the umbilical area is proportionately smaller, and the 

 end of the rib less broad and prominent. Meyer's species seems also to be a 

 much smaller shell, and has a conical, not flattened, spire. 



•Teinostoma steiratum n. s. 



Plate 23, figure 11. 



Newer Miocene of the Cape Fear River, North Carolina. 



Shell small, polished, solid, three-whorled ; spire flattened above, 



obscurely microscopically spirally striate near the suture and umbilicus ; 



early whorls with an angle on the upper surface, close to which the suture is 



wound, forming a narrow channel, but on the last whorl the angle becomes 



obsolete and the upper surface evenly rounded ; periphery with a single narrow 



