FAUNA OF ORTHAULAX PUGNAX ZONE. 61 



ened, not internally lirate; inner lip smooth; pillar Avith four plaits, 

 the largest posterior, the others regularly diminishing forward, the 

 most anterior not quite reaching the edge of the pillar; canal rather 

 Avide and deep, slightly recurved. Length of shell 15.5, of last Avhorl 

 9, of aperture 6, maximum diameter 4.5 mm. 



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



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

 165067. 



MITRA MYRA, new species. 



Plate 12, fig. 7. 



Shell small, acute, A\dth 6| Avhorls, of Avhicli the first 2 are smooth, 

 subsequent Avhorls being sculptured AA'ith narroAv rounded riblets 

 (on ithe penultimate A^'horl 12) slightly protractiA^e and Avith Avider 

 interspaces, A^dlich extend from suture to suture, making slight un- 

 dulations in the sutural line A\diere the ends of the riblets reach it; 

 on the last Avhorl the riblets are carried OA^er the periphery and be- 

 come obsolete on the base ; there is no spiral sculpture except on the 

 canal, Avhere there are 4 threads, the anterior pair close set, small, 

 the third large Avith a marked sulcus on each side, and the fourth 

 faint at the base of the Avhorl; the remainder of the surface is 

 smooth; aperture narroAA% less than half the length of the shell; 

 outer lip (defectiA^e in the specimen) ; pillar strong, Avith three 

 strong, oblique plaits decreasing in prominence f orAvard ; canal short, 

 Avide, A^ery slightly recurA^ed. Length of shell 8, of last Avhorl 5.8, 

 maximum diameter 3.5 mm. 



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



One specimen in the Post collection, JJ. S. Nat. Mus., No. 165068. 



Genus STRIGATELLA S^Arainson. 



Strigatella Swainson, Mai., p. 319, 1840, Type, Mitra sehra Lamarck. 



STRIGATELLA AMERICANA, new species. 



Plate 9, fig. 2. 



Shell oA'oid, heaA^y, Avith a short acute spire of 7 Aviiorls, exclusive 

 of the (lost) protoconch; upper Avhorls closely spirally threaded, 

 the threads disappearing in front of the shoulder on the last Avhorl ; 

 suture closely appressed; axial sculpture of fine rounded riblets, 

 Avith equal interspaces traversing the Avhole A^udth of the last Avhorl, 

 but faint and irregular on the spire; outer lip much thickened Avith 

 a prominent nodule internally near the middle; body Avith a thin 

 Avash of callus ; pillar A\ath four stout nearly horizontal plaits, Avith 

 Avider interspaces; canal short, narroAV, sharply recurA^ed; siphonal 



