106 



VARICELLA, JAMAICA. 



glossy. The surface grooves weaken rapidly downwards. 

 The figured specimen is 18.8 nun. long ; the largest is 21 x 6, 

 apert. 8 mm., with 7y 2 whorls. The upper fold of the colu- 

 mellar callus is not always distinctly developed. The in- 

 ternal structure does not differ from V. similis. 



Closely related to this form are shells taken by Henderson 

 at Ipswich and Withorn, in which the groove-sculpture is 

 decidedly stronger than in typical similis, and the columella 

 approaches the form shown in var. ~biplicatula. 



Var. longa n. v. PI. 17, fig. 18. 



At Mt. Diablo a very slender form was taken 'by Hender- 

 son. It is typical in sculpture and color, but has the colu- 

 mella strongly concave, calloused inside, yet the axis is not 

 gyrate, no central hole being visible in basal view. The aper- 

 ture is small, and the whorls are more numerous. Length 

 22.5, diam. 5, aperture 6 mm., whorls 9i/o. 



Group of V. cochlidium. 



Small, slender, pellucid Varicellas with groove sculpture, 

 inconspicuous varices, and about 2% smooth embryonic 

 whorls; columella strongly concave, truncate basally; axis 

 spirally ascending, in the typical forms coiled about a cen- 

 tral hollow as seen from the base. This group in its typical 

 species seems quite distinct, yet V. similaris to some extent 

 connects it with the typical group of Varicella, through 

 V. similis. 



49. V. SIMILARIS Pilsbry, n. sp. PI. 17, figs. 14, 15, 16. 



The shell is slender, tiirrite, thin, corneous-yellowish and 

 somewhat translucent; general outlines of the spire nearly 

 straight, but the whorls are convex. The apex is obtuse; 

 embryonic shell of 2y 2 whorls, the first two smooth, then fine 

 and rather close strife very weakly beginning. The post- 

 nepionic whorls have a very weak sculpture of unequally 

 spaced grooves, much as in V. similis but weaker. The occa- 

 sional varix-lines are rather weakly impressed, and either 

 plain or preceded by a narrow brown streak, or by a faint 

 spot below the suture. The aperture is small, piriform, 



