NO. 2 PYRAMIDELLID MOLLUSKS — BARTSCH 63 



maining measure: Length 5.2 mm., diameter 1.8 mm. Another speci- 

 men, not quite adult, is in the collection of the A.N.S.P. This has 

 furnished the description of the nucleus. 



I take pleasure in naming this species for Jay A. Weber, whose 

 collecting of Tertiary Florida mollusks has contributed materially 

 to our knowledge. 



CHRYSALLIDA DALLI, new species 

 Plate 15, figure 6 



Shell small, ovate, cream-yellow. The nucleus consists of 2.5 well- 

 rounded smooth whorls, which are obliquely almost half immersel 

 in the first postnuclear turn. The postnuclear whorls are well rounded 

 and marked by very strong, slightly retractively slanting axial ribs, 

 of which 12 are present upon the second, 13 upon the third, 14 upon 

 the fourth, and 15 upon the last turn. The axial sculpture upon the 

 first postnuclear whorl, as well as the spiral sculpture, is much finer, 

 that is, less strongly developed. The intercostal spaces are about as 

 wide as the ribs. The spiral sculpture consists of four cords, of 

 which the one at the summit is weaker than the rest, which are of 

 equal size. The junction of the axial ribs and spiral cords produce 

 very strong oval tubercles whose long axis corresponds with the spiral 

 cords. The tubercles of the cord at the summit, being smaller than 

 those of the second cord, gives to the whorls a sloping-shoulder effect. 

 The suture is deeply constricted and rendered sinuous by the tubercles 

 at the summit of the whorls. The periphery of the last whorl is 

 deeply grooved and crossed by the weakened axial ribs which extend 

 to the first basal spiral cord. The base is broad, hemispherical, marked 

 by nine spiral cords, the first of which is almost as strong as the cord 

 above the periphery ; the rest grow consecutively less strong, the last 

 being mere elevated threads. The aperture is elongate-ovate, effuse 

 at the junction of the basal lip and the columella; the columella is 

 thin, slightly curved, oblique and slightly reflected, and bears a strong 

 internal fold at its insertion; the parietal wall is covered by a thin 

 callus; the outer lip is thin, gently curved and rendered sinuous by 

 the external spiral cords. 



The type, U.S.N.M. No. 561700, comes from the PHocene of North 

 St. Petersburg, Fla. It has 5.6 postnuclear whorls and measures: 

 Length 3.1 mm., diameter 1.2 mm. An additional specimen is in the 

 collection of the A.N.S.P. 



I take pleasure in naming this exquisite species for that master 

 paleontologist Dr. William H. Dall, whose exhaustive report on the 



