58 STROBILOPS. 



7. Low conic; 3 basal folds. Mexico. 



S. aenea mexicana, No. 4c. 



Rather high conic; 3 basal folds and one above periphery. 



Old Providence Island S. piratica, No. 20. 



20. Strobilops piratica, Pils. PL 13, figs. 8, 9, 10, 11. 



The shell is conic with the lateral outlines of the spire some- 

 what convex; umbilicate, the width of umbilicus contained 5 

 to 6 times in the diameter of the shell. There are 51/2 whorls, 

 the first 11/2 smooth, the rest with sculpture of retractive 

 riblets, which are about half as wide as their intervals on the 

 penult whorl; on the last whorl they are somewhat unevenly 

 spaced, partly closer. They pass over the periphery and con- 

 tinue over the base. The periphery is weakly subangular in 

 front of the aperture, elsewhere rounded. The aperture has 

 a blunt, weakly expanded lip and a moderately strong parietal 

 callus. The parietal lamella is strongly developed and pen- 

 etrates inward slightly more than a half whorl. Its slightly 

 thickened edge has swollen nodes bearing minute points and 

 granules. The infraparietal lamella penetrates inward nearly 

 as far as the parietal, is similarly nodose and emerges very 

 weakly. There is a short interparietal lamella consisting of a 

 series of tubercles weakly connected. The palato-basal barrier, 

 situated nearly a half whorl inward, consists of four folds: 

 three in the basal wall, the middle one much the higher, the 

 outer one narrow and low, and one small, very narrow fold 

 above the periphery. 



Height 2 mm., diam. 2.2 mm. 



Old Providence Island : on the summit of the ridge north of 

 High Peak, in leaf debris of forest. Type No. 150860 ANSP, 

 paratypes No. 150862. 



StrohUops piratica Pilsbry, Proc. A. N. S. Phila., vol. 82, 

 p. 256, pi. 19, figs. 9-11. July 18, 1930. 



This species has a higher, more couvexly conic shape than 

 S. veracruzensis, with a wider umbilicus. By the possession 

 of a palatal fold above the periphery and of ribs on the base it 

 differs from the Mexican forms, and resembles some northern 



