FAUNA OF ORTHAULAX PUGNAX ZONE. 91 



on the two succeeding whorls 1, on the next whorl 3, on the fourth 

 whorl 4, and on the last whorl 8 spiral ridges, crossing about 16 

 axial ribs and slightly nodulous at the intersections, the interstitial 

 reticulations looking like squarish pits; the whorls are slightly tur- 

 reted by the sculpture and the suture very distinct; the aperture 

 ovate, the outer lip thickened and outwardly denticulated by the 

 ends of the spirals ; a thick layer of callus on the body ; the anterior 

 sulcus distinct, the whorls under the sculpture well rounded ; length 

 of shell 5.2, of last whorl 3, maximum diameter 2.3 mm. 



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

 specimen. U. S. Nat. Mus. No. 166105. 



This species is nearest to C. milium Dall, of the Pleistocene and 

 recent fauna at Colon, Panama. 



Genus POTAMIDES Brongniart. 



Potamides Beongniaet, Ann. du Museum, Paris, vol. 15, 1810, p. 368. Sole 

 example. P. lamarckii Brongniart. Oligocene. 



POTAMIDES HILLSBOROENSIS Heilprin. 



Plate 8, fig. 5. 



CeritUum. hillsJ)oroensis Heilprin, Trans. Wagner Inst., vol. 1, p. 124, pi. 



8, fig. 67, 1887. 

 Potamides hillsborocnsis Dall, Trans. Wagner Inst., vol. 3, pt. 2, p. 286, 

 pi. 15, fig. 12, 1892. 

 Tampa silex beds, Dall; also in the overlying Orbitolite bed or 

 Tampa limestone at Ballast Point and on the Hillsboro river near 

 Tampa Bay, and on the Chattahoochee Eiver near the railway bridge 

 at Chattahoochee, northwest Florida, and in the Wakulla county 

 limestone; Burns and Willcox. U. S. Nat. Mus. No. 164700. 



POTAMIDES (LAMPANELLA) TRANSECTA Dall. 



Plate 14, fig. 3. 



Potamides (Lampanella) transecta Dall, Trans. Wagner Inst., vol. 3, pt. 

 1, p. 189, pi. 11, fig. 7, 1890 ; pt. 2, p. 287, 1892. 

 Tampa silex beds at Ballast Point, Tampa Bay, Florida, where it 

 is not uncommon, Willcox, Burns, and Dall. U. S. Nat. Mus. No. 

 112525. 



Subgenus PYRAZISINUS Heilprin. 



Pyrazisinus Heilprin, Trans. Wagner Inst., vol. 1, p. 115, 1887.— Dall, 

 Trans. Wagner Inst., vol. 3, pt. 2, p. 287, 1892. 

 Sole example and type P. campanulatus Heilprin. 



