NO. 2 PYRAMIDELLID MOLLUSKS — BARTSCH 75 



CHRYSALLIDA SMITHI, new species 

 Plate 1 6, figure I2 



Shell very large, elongate-conic, cream-yellow. The nucleus con- 

 sists of about 2 rounded whorls that form a depressed helicoid spire 

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

 first of which the nucleus is half obliquely immersed. The postnuclear 

 whorls are strongly rounded and slopingly shouldered from the 

 second spiral cord to the summit. They are marked by strong axial 

 ribs which pass equally strong from the summit to the periphery. Of 

 these ribs i6 are present on the second whorl of the type, i8 upon the 

 third, 20 upon the fourth, 22 upon the fifth, and 30 upon the last 

 turn. The intercostal spaces are much narrower than the ribs. The 

 spiral sculpture consists of 4 very strong cords which are not of equal 

 strength, the second below the summit of the whorls being the 

 strongest, followed by the third, then the cord at the summit, and last 

 the cord above the periphery. The spaces separating the spiral cords 

 are about one-fourth as wide as the cords. The junction of the axial 

 ribs and the spiral cords forms strongly elevated, somewhat oblong 

 tubercles whose long axis coincides with the axial ribs. The spaces 

 enclosed by the spiral cords and axial ribs are rounded pits. The 

 suture is deeply channeled and rendered wavy by the tubercles at 

 the summit. The periphery is marked by a spiral cord, which is a 

 little less strong than the one above it and separated from the fourth 

 cord by a groove which is a little wider than that separating the 

 fourth from the third. This groove is crossed by the weak continua- 

 tion of the axial ribs. The base is marked by six spiral cords that 

 grow consecutively weaker from the periphery basalward. The aper- 

 ture is elongate-ovate and effuse at the junction of the basal lip and 

 columella; the columella is oblique and provided with a strong fold 

 at its insertion ; the parietal wall is covered by a thin callus ; the outer 

 lip is gently curved and rendered wavy by the external spiral cords. 



The type, U.S.N.M. No, 561717, comes from the Pliocene of 

 North St. Petersburg, Fla. It has 7 whorls remaining and measures : 

 Length 5.1 mm., diameter 2.0 mm. U.S.N.M. No. 561718 contains 

 a not quite adult specimen from the same source that has furnished 

 the description of the nucleus. Another specimen is in the collection 

 of the A.N.S.P. 



The large size will easily distinguish this species from all the 

 Chrysallidas here described. 



I take pleasure in naming this species for Maxwell Smith, whose 

 publications have done much to help popularize the study of mollusks. 



