BRACHYPODELLA, JAMAICAN. 89 



Key to Jamaican species of Brachypodella. 

 I. Last whorl subangular or somewhat carinate below; 

 sculpture of fine stride; axis slender and straight; aper- 

 ture subcircular, the lip narrow. Section Simplicervix. 



1. Length 9-10.5 mm., about 8 whorls remaining; base 

 merely subangular; a short neck. 



B. inornata, no. 41. 



2. Length nearly 8, diam. 2.5 mm., 10% whorls re- 

 maining, basal carina moderately sharp. 



B. simplex, no. 42. 



3. Length 5, diam. 1.25 mm., 8-8% whorls remaining, 

 the last scarcely produced, subangular below. 



B. humttis, no. 43. 

 II. Last whorl strongly carinate below. 



1. Small (length 5-10 mm.), sculptured with contin- 

 uous or interrupted ribs ; whorls 8-10 in truncate, 

 about 16 in entire shells; axis thin and straight. 

 Section Geoscala. 



a. Ribs continuous, distant, about 10 on the 

 penult, whorl; length 5.5 to 6.5 mm. 



B. costulata, no. 38. 



aa. Larger, length (truncate) 7.5 to 9 mm.; ribs 

 more numerous. 



&. Ribs interrupted in the middle of each 

 whorl; suture only moderately im- 

 pressed. B. rolertsi, no. 39. 

 &&. Suture deeply impressed or constrict- 

 ing. B. seminuda, no. 40. 



2. Shell larger, white, pillar-shaped, the whorls more 

 numerous, short, flattened, very finely and evenly 

 striate, the last projecting, squarish. Aperture as 

 wide as long; axis straight and thick, variously 

 sculptured. Section Mychostoma. 



a. Sinistral. 



&. Large; axis cylindric or spool-shaped in 

 each whorl. B. agnesiana, no. 44. 



&&. Smaller, length 17-19, diam. 2.7 mm.; 

 axis armed with hooked processes. 



B. diminuta, no. 45. 



