84 PUPILLA. 



toothed : angular lamella in form of a callous pad within the 

 posterior angle, parietal lamella short, stout, deeply placed, 

 columellar lamella low and broad, palatal fold a rounded, 

 deeply placed tubercle. (Other forms of the species may 

 lack all but the angular pad.) 



Length 2.8 mm.; diam. 1.5 mm., 51/2 whorls. (Holotype.) 



Length 3.1 mm., diam. 1.5 mm. ; 5% whorls. 



Guadalupe Island, Lower California, 1000 ft. above North- 

 east Anchorage ; also from 2 miles north of south end, on the 

 east side, near sea level at N-E. Anchorage and on the crest 

 of Pine Eidge at an elevation of 3000 ft. (G. D. Hanna). 



Pupilla guadalupensis Pilbry, Proc. Cal. Acad. Sei. (4), 

 XVI, 1927, p. 173, pi. 7, f. 1, 2. 



The close, regular, evenly developed ribs distinguish this 

 species from other American Pupillse, the other two species of 

 the subgenus Striopupilla having the ribs more uneven and 

 more widely spaced. It resembles the Asiatic Pupilla annan- 

 dalei, which, however, belongs to a different subgenus. 



As in most species of this genus, the parietal, columellar 

 and especially the palatal teeth are variable, either present or 

 absent. The angular pad appears in all adult individuals, and 

 is sometimes the only tooth present, as in fig. 11. The four- 

 toothed form, selected as typical on account of its status as the 

 most primitive form, is exceptional in some lots seen, but 

 common in other lots. 



Five specimens taken at random from the type lot have 

 teeth as follows : 



1. Angular, parietal, columellar, palatal. 



2. Angular, parietal, columellar, palatal. 



3. Angular, parietal, 



4. Angular, columeUar, 



5. Angular, 



In No. 2 the parietal is very small ; in No. 4 the columellar 

 can be seen only in an oblique view in the aperture. 



A similarly unselected lot of ten, from two miles north of 

 the south end of the island, has teeth as follows: 



