FAUNA OF ORTHAULAX PUGNAX ZONE. 31 



of the coil so that the apex is hidden under a deep perforation ; the 

 surface is smooth ; on the basal side (which in the specimen is badly 

 obscured), the whorls seem to have formed a flattened concavity with 

 all the whorls visible and separated by a closely appressed suture ; it 

 is not certain whether or not there was on the lower side a carina on 

 which the suture was laid; periphery evenly and almost symmetri- 

 cally rounded ; aperture broken off in the specimen. Diameter of three 

 whorls as figured 12.5 mm., that of the whole shell probably exceeded 

 16 mm. Height of the three remaining whorls 4.5 mm. 



Tampa silex beds, at Ballast Point, Tampa Bay, Florida. 



Type from the Post collection, U. S. Nat. Mus. No. 165020. 



Section TORQUIS Dal!. 

 Torquis Dall, Harriman Exp. Rep. Land and fresh water Moll., p. 86, 1905. 

 Type.—Planorhis parvus Say. 



PLANORBIS (TORQUIS) WILLCOXII Dall. 



Plate 3, figs. 5, 6. 



Planorbis willcoxii Dall, Trans. Wagner Inst., vol. .3, pt. 1, p. 4, pi. 1, figs. 

 6c, 6^, Aug., 1890. 



Tampa silex beds at Ballast Point, Tampa Bay, Florida. Dall. 

 U. S. Nat. Mus. No. 111938. 



The original type remains the only specimen of this species which 

 has been brought to my attention. 



PLANORBIS (TORQUIS) ELISUS, new species. 

 Plate 1, figs. 8, 9. 



Shell small, depressed, almost symmetrically coiled, with at least 

 four and a half whorls; periphery evenly rounded; surface smooth, 

 except for inconspicuous incremental lines; suture rather deep; if 

 regarded as dextral the upper surface displaying all the whorls, has 

 the apex depressed in a broadly funicular space formed by the flat- 

 tening of the coil; on the basal side the whorls evenly succeed one 

 another without flattening; aperture defective. Height of shell 

 1.2, maximum diameter 4 mm. 



Tampa silex beds, at Ballast Point, Tampa Bay, Florida. One 

 specimen from the Post collection, U. S. Nat. Mus. No. 165021. 



FAMILY OLEACINIDAE. 



Genus SPIRAXIS C. B. Adams. 



SPIRAXIS? TAMPAE, new species. 



Shell small, thin, smooth, of five rapidly elongating whorls; apex 

 rounded blunt, smooth, suture distinct, not crenulate; later whorls 



