214 ACHATINELLA VULPINA. 



It appears that an ancestral stock, probably not unlike the 

 yellowish form of virens, spread over a considerable area; 

 various mutations arose in different places, and radiated 

 from their initial points as far as time and conditions al- 

 lowed, hybridizing with other mutations. Nuuanu, deeply 

 cut, with a broad level floor, has been a partial barrier to the 

 spread of mutations reaching it during the present climatic 

 cycle. 



The races from the northern or Koolau valleys have long 

 been in a measure isolated from those of the Kona slope. 

 Intrinsically these races are on a par with the elementary pat- 

 terns of the southern watershed, but by favor of their isola- 

 tion they have not been caught in the web of hybridism which 

 clings about the Kona forms. They may properly be recog- 

 nized as subspecies. See page 224. 



Races and elementary patterns of A. vulpina. 

 (No dark sutural border.) 



Chestnut or blackish below, gradually paler towards the 

 suture, vulpina pattern, pi. 39, f . 1, la. 



Upper third of last whorl yellow, lower two-thirds chestnut, 

 the division abrupt, castanea pattern, pi. 39, f. 2. 



Yellow, uniform, or (typically) banded with black-brown, 

 N.-E. Nuuanu, ernestina pattern, pi. 39, f. 3-4. 



Green, either dark or pale, varying to olive or ochreous, 

 olivacea pattern, pi. 40, figs. 3-4a. A form in which the shell 

 is somewhat rugose has been named cucumis Gul. 



(A brown or blackish sutural border.) 

 Kona forms. 



Base dark chestnut, upper surface lighter or yellow, Pauoa, 

 adusta pattern, pi. 40, figs. 1, 2. 



Green, varying to chestnut or yellow, sutural band narrow, 

 virens pattern, pi. 40, figs. 5, 5a. 



Similar, but with a broad sutural band and rarely another 

 above the periphery, Kahauiki, suturalis pattern, pi. 40, figs. 

 9-106. 



Having blackish-brown bands i, ii and iii in the prismatic 



