78 VARICELLA, JAMAICA. 



This species was based on a single specimen drawn in fig. 

 56. It measures 7.8 mm. long, 2 wide, aperture 2.4 mm. 

 long, with fully 7 l / 2 whorls. The first 1^2 whorls are smooth, 

 the second whorl being somewhat disproportionately high. 

 The sculpture is very even, of straight, low, rounded, riblets 

 or plaits, 'wider than their interstices, about 10 in a mm. on 

 the last whorl. There are three very inconspicuous varix- 

 lines or growth-arrest lines, on the last whorl. The aperture 

 is slightly oblique, the outer lip arched forward in the 

 middle. Columella subvertical, somewhat ^concave above, 

 curving into the parietal margin, obliquely truncate at the 

 base. 



24a. Var. ROPERI n. subsp. PI. 10, fig. 55. 



Specimens from Porus, Richmond Vale, and several lots 

 without exact locality, differ from Adams' type by the more 

 slender 'contour; narrower aperture, shorter columella and 

 coarser sculpture, there being but 7 folds in one mm. on the 

 last whorl. The first whorl only is smooth. One from Porus 

 figured measures, length 8.5, diam. 1.9, length of aperture 

 2.1 mm. ; whorls 714. 



In basal view a minute axial perforation or false-umbilicus 

 may be seen, as in V. Icvis. 



Porus (Edw. W. Roper) ; Richmond Vale (Mrs. E. M. 

 Swainson). 



V. tcnera is not closely related to the preceding forms. It 

 stands between them and the group of V. coclilidmni. 



25. V. COSTULOSA (C. B. Adams). PI. 7, figs. 14, 15, 16, 17. 



"Shell conic, turrited: translucent, very pale brownish 

 horn color, darker at the varices : with the surface apparently 

 striated, but having on each whorl about seventy small ap- 

 proximate regular ribs- ; but the nuclear whorls are smooth ; 

 with rather indistinct varices, of which there are two or three 

 on each whorl: apex rather obtuse; spire with the outlines 

 nearly rectilinear, except near the apex : whorls nearly nine, 

 moderately convex, with a well impressed suture : aperture 

 broadly ovate : labrum not advanced along the middle, much 



