52 VARICELLA. 



a 1 . Ribs unarmed, 13 to 15 on last whorl, intervals with' 

 18-20 'fine stria and spiral lines; reddish-brown, not 

 streaked; 12 x 3 mm. with 9 whorls; W. Cuba. 



V. picJiardi, no. 2. 



II. Surface not spirally striate, though sometimes the longi- 

 tudinal strife are a little waved ; corneous or pale brown, 

 not streaked. 



a. East Cuban forms. 



&. 14 low compressed ribs on last whorl; 6 x 1.75 



mm. with 8 whorls. V. scalarina, no. 5. 



& 1 . Elevated, cord-like ribs; 9.5 x 2 mm., with 10 



whorls. V. multicosta, no. 7. 



a 1 . Middle and west Cuban forms, etc. ; <columella not 



truncate or very indistinctly so. 



&. Axis; gyrate, a central false umbilicus visible- 

 from.' the base ; very slender, 6 x 1.6 to 7 x 1.75 

 mm., 7 or 8 whorls. 



c. About 20 ribs on last whorl, 4 to 5 striae 

 in each interval. V. gracillima, no. 3. 



c 1 . 9 to 12 striae in each interval. 



V. g. sanct-ithomensis, no. 3&. 

 c 2 . About 25 ribs on last whorl, 6 to 8 striae 

 in each interval. 



V. g. floridana, no. 3a. 



6 1 . Axis straight, no central hole visible from the 

 base; shell less slender, diam. 2 mm. or more, 

 c. 20 to 21 smooth ribs on last whorl, 8 to 11 

 striae in each interval; 8 to 9.5 mm. long. 



V. manzanillensis, no. 4. 



c 1 . 16 to 18 ribs on last whorl, 10 striaa in each 

 interval; 6 to 7 mm. long. 



V. m. cienfuegosensis, no. 4&. 



c 2 . 24 to 29 ill-developed ribs on last whorl, 



5 to 7 striae in each interval, 8 to 9 mm. 



long. V. m. trinitatis, no. 4a. 



1. V. ACUTICOSTATA (Orbigny). PI. 15, figs. 1, 10. 



Shell tapering, turrite, attenuate near the summit, thin, 



