VARICELLA. 65 



5 striae; and there are very weak spiral cords, almost obso- 

 lete. There are two or three slightly projecting varices on 

 the last whorl, distinguishable from ribs by their more arcu- 

 ate, sinuous shape. They are preceded by very faint brown 

 streaks. The last whorl is flattened peripherally. Aperture 

 slightly oblique; columella vertical, obliquely and narrowly 

 truncate at the base. 



Length 16, diam. 3.9, aperture 4.1 mm.; whorls 9%- 



Length 14, diam. 3.3, aperture 3.7 mm.; whorls 9 1 / 4. 



Length 14.9, diam. 3.2, aperture 4 mm.; whorls 9%. 



Jamaica (T. Bland). St. Davids (C. B. Ad.). 



This species is represented by several lots in the collec- 

 tion oif the Academy, and also is in the Adams collection at 

 Amherst. It is related to V. adamsiana, but differs by the 

 much more numerous and less waved ribs, fewer and finer 

 striae in the 'intervals, and by the much more robust embryonic 

 shell, with striae between the riblete throughout. In V. 

 chittyana the last embryonic whorl has a diameter of fully 

 1.3 mm., while in adamsiana it hardly exceeds 1 mm. The 

 embryonic shell usually consists of 3% to 3% whorls, but 

 there is one specimen before me with only 2% whorls. 



In the C. B. Adams collection there is a specimen of this 

 species, under the name A. gossei, from St. Davids. It dif- 

 fers slightly from my types in having 7 to 8 threads in each 

 intercostal interval, length 15, diam. 3.7, apert. 4 mm., whorls 

 91/3. The apex of this shell is figured, pi. 14, fig. 33. 



There is also a form with longer whorls, and reaching a 

 larger size, usually with 6 to 8 striae in each interval, but with 

 the same number of primary riblets. A specimen measures, 

 length 20, diam. 3.75, aperture 4.9 mm., whorls 



12. Y. GOSSEI (Pfeiffer). PI. 14, fig. 31. 



Shell subulate, thin, diaphanous, waxen, remotely ribbed, 

 very finely striate vertically between the ribs on the last 

 whorl. Whorls 9 to 10, a little convex, the last slightly more 

 than one-fourth the total length. Columella oblique, reach- 

 ing to the base of the aperture, shortly truncate. Aperture 

 narrow, oblong; peristome simple, the right margin dilated 



