120 ACHATINELLA, SECTION BULIMELLA. 



the genus, some forms being irregularly corrugated in the 

 direction of the lines of growth. Spiral sculpture is weak or 

 obsolete in all the species. 



There are three collateral groups or series of species in 

 Bulimella, the first subdivided as a convenient geographic di- 

 vision. 



Series of A. byronii: shell oblong-conic, often -with streaks 

 or bands of dark green, and often roughly striate or corru- 

 gated; mainly dextral. A. byronii, pidcherrima, decipiens, 

 lila. 



Series of A. viridans: a subdivision of the above series, fo-r 

 the exclusively dextral species of the eastern end of the range. 

 A. abbreviata, viridans, and tceniolata. 



Series of A. bidimoides: shell ovate, capacious, never 

 marked with green; smooth, dextral or sinistral. A. rosea, 

 bidimoides, elegans. 



Series of A. fuscobasis: shell ovate-come, never marked with, 

 green; smooth; mostly sinistral. A. fuscobasis, sowerbyana, 

 pupukanioe. 



On account of the wide variation in shape and color, it is 

 not possible to rigidly diagnose these groups, which never- 

 theless express the natural affinities of the species. 



Key to species and most subspecies of Bulimella. 



I. Forms of the southeastern third of the main range (east of 



Mjoanahia) . 



a. Lip acute, but slightly or not thickened within ; shell dex- 

 tral, very smooth, richly colored. A. abbreviala, no. 1. 

 a 1 . Lip strengthened by a callous rib. 

 b. Shell dextral. 



c. Streaked with green or chestnut on a lighter or 



yellow ground. A. viridans, no. 2. 



c 1 . Banded or streaked with chestnut on a white 



ground, or white. A. tceniolala, no. 3. 



6 1 . Shell sinistral. 



c. Shell white with few brown bands or none, about 

 16 x 10 mm. A. fuscobasis, no. 11. 



c 1 . Similar but larger and more capacious. 



A. f. lyonsiana, no. lla. 



