NO. 2 PYRAMIDELLID MOLLUSKS — BARTSCII I9 



Shell not large. 



Shell of medium size. 

 Shell cylindric. 



Axial ribs vertical curytioni 



Axial ribs retractive hesperusi 



Shell not cylindric. 



Shell turrited atlasi 



Shell not of medium size, small. 

 Axial ribs vertical. 



Shell very slender antaeusi 



Shell not very slender terra 



Axial ribs not vertical. 

 Axial ribs protractive. 



Shell stout cacitsi 



Shell not stout cerberusi 



TURBONILLA (CHEMNITZIA) ACISI, new species 

 Plate 3, figure 2 



Shell minute, elongate-turrited, cream-yellow. The nucleus is 

 decollated in both specimens. The postnuclear whorls are very slightly 

 rounded and crossed by very strong, slightly protractively slanting 

 axial ribs which are thickened at the summit, where they appear al- 

 most nodulose ; they are likewise thickened at their peripheral termina- 

 tion, giving the periphery the appearance of possessing a spiral cord. 

 Of these ribs, i6 are present upon the last whorl of the type which 

 appears not quite adult. The intercostal spaces are about as wide 

 as the ribs and are deeply impressed and terminate abruptly at the 

 periphery. Base short, well rounded, without sculpture. Aperture 

 subquadrate. 



The type, U.S.N.M. No. 561609, comes from the Pliocene de- 

 posits of North St. Petersburg, Fla. It has 8.8 whorls remaining, 

 having lost the nucleus and probably a part of the first postnuclear 

 whorl, and measures : Length 3.7 mm., diameter i mm. An additional 

 specimen is in the collection of the A.N.S.P. 



TURBONILLA (CHEMNITZIA) ADMETA, new species 

 Plate 3, figures 6a, b 



Shell large, elongate-turrited, cream-yellow. The nucleus consists 

 of 2.5 strongly rounded turns, which form a rather elevated spire 

 whose axis is at right angles to that of the succeeding whorls, in the 

 first of which the last whorl is about one-fourth immersed. The 

 postnuclear whorls are strongly rounded and crossed by very strong, 

 protractively slanting axial ribs, which are broader than the spaces 



