"JT. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I25 



enclosed by the axial ribs and spiral cords are deep, round pits. The 

 suture is constricted and rendered very conspicuous by the shouldered 

 summit of the whorls. The strong tubercles also render it wavy. 

 The base is hemispherical and bears a strong spiral cord below the 

 deep groove that marks the periphery. Anterior to this cord are mere 

 indications of four additional cords. The aperture is elongate-oval, 

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

 is stout, vertical, and provided with a strong fold ; the parietal wall is 

 glazed 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. 561712, comes from the Pliocene of North 

 St. Petersburg, Fla. It has 5.9 postnuclear whorls and measures: 

 Length 2.8 mm., diameter 1.4 mm. U.S.N.M. No. 561713 contains 

 another specimen from the same source and another is in the collec- 

 tion of the A.N.S.P. 



The elongate-ovate shape will readily distinguish this from the 

 other species having a deeply channeled suture. 



I take pleasure in naming this species for William Stimpson, one 

 of America's pioneer conchologists. 



CHRYSALLIDA LEAI, new species 

 Plate 16, figure 8 



Shell rather large, elongate-conic, cream-yellow. The nucleus is 

 decollated. The postnuclear whorls are slightly rounded. On the 

 first two the sculpture is obsolete. On the third, 12 axial ribs are 

 present, on the fourth and fifth 14, while the last turn shows 16. 

 These ribs extend equally strong from the summit to the periphery. 

 The intercostal spaces equal the ribs in width. The spiral sculpture 

 consists of four cords which equal the axial ribs in strength. They 

 are subequal in width and equally spaced. The spaces enclosed by 

 the axial ribs and spiral cords are deep, rectangular pits whose long 

 axis coincides with the spiral cords. The suture is deeply channeled 

 and rendered wavy by the strong tubercles at the summit; it shows 

 the edge of the peripheral spiral cord. The periphery is marked by 

 a spiral cord which is almost as strong as those on the spire but lacks 

 the strong tubercles. The base is hemispherical, narrowly umbilicated, 

 and marked by four weakly developed spiral cords and numerous fine 

 axial threads. The aperture is ovate ; the columella is thin-edged and 

 provided with a strong fold at its insertion; the parietal wall is cov- 

 ered by a thick callus which renders the aperture complete ; the outer 

 lip is thin, strongly curved, and rendered sinuous by the external 

 spiral cords. 



