NO. 2 PYRAMIDELLID MOLLUSKS — BARTSCH "JJ 



i8 upon the fifth, and 20 upon the last whorl. The intercostal spaces 

 equal the ribs in width. The junction of the axial ribs and spiral cords 

 forms rounded tubercles while the spaces enclosed by them are deep 

 round pits. The suture is moderately constricted, not channeled. The 

 periphery is marked by a feebly nodulose spiral cord that equals those 

 above it in strength. The space between the peripheral spiral cord 

 and the fourth cord of the spire is a little wider than the spaces 

 separating the cords on the spire. The base is strongly rounded with 

 a slight umbilical chink ; it is marked by five spiral cords, which grow 

 consecutively weaker from the periphery basalward. It also has nu- 

 merous fine axial raised threads best seen in the spaces between the 

 spiral cords. The aperture is ovate, effuse at the junction of the 

 basal lip and columella; the columella is straight with its edges re- 

 flected and bears a strong fold at its insertion; 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. 561720, comes from the Pliocene of North 

 St. Petersburg, Fla. It has 6.3 whorls remaining and measures : 

 Length 4.0 mm., diameter 1.5 mm. Another specimen from the same 

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



The strong basal spiral cords easily distinguish this species from 

 Chrysallida tuomeyi (below). 



I take pleasure in naming this species for Thomas McGinty, who 

 has done much collecting of Recent and fossil mollusks in Florida. 



CHRYSALLIDA TUOMEYI, new species 



Plate 16, figure 14 



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

 about 2 whorls that form a low helicoid spire whose axis is at right 

 angles to that of the postnuclear whorls, in the first of which it is 

 about one-third immersed. The postnuclear whorls are almost flat- 

 tened, which gives to the lateral outline of the shell an almost straight- 

 line appearance. The postnuclear whorls are marked by strong, de- 

 cidedly retractively slanting axial ribs, which are of the same strength 

 from the summit to the periphery. Of these ribs, 12 are present upon 

 the second, 14 upon the third, 16 upon the fourth, and 18 upon the 

 last whorl. The intercostal spaces are as wide as the ribs. The spiral 

 sculpture consists of four equally and strongly developed cords, 

 which equal the axial ribs in strength. The space separating the 

 cord at the summit from its neighbor is narrower than the spaces that 

 separate the rest of the cord, which are about as wide as the cords. 



