340 WAIANAE SPECIES. 



cient Waianae fauna probably had no arboreal Achatiiiellae ; 

 at least we have no evidence of any. 



Color and form characteristics and distribution. On the 

 north side of the range the shells are either blackish-brown 

 with a white subsutural band (mustelina pattern), or of var- 

 ious shades of drab or vinaceous buff, more or less streaked, 

 with or without spiral lines or bands (multilineata pattern). 

 My very limited experience in the Waianae range leads me 

 to believe that as a general rule the dark forms are lower, the 

 light and banded higher on the ridges, although the transition 

 is gradual, and probably no colony of dark shells is pure. In 

 the west (Mokuleia, etc.), the white sutural band is quite 

 narrow. Eastward it becomes broader, culminating in the 

 ~bicolor pattern of Lihue. In the middle section of the range 

 (Haleauau, Popouwela) the white sutural band is intermed- 

 iate in width. Properly speaking, no line can be drawn be- 

 tween typical mustelina and bicolor-, and both, in their re- 

 spective districts, merge directly into multilineata-monacha 

 and bandless patterns of various tints. 



It appears thus that there has been some differentiation 

 vertically, and more horizontally, along the range; but the 

 continuity of the forests has favored migration, so that from 

 the systematic standpoint, bicolor, multilineata and monacha 

 cannot well be defined as races distinct from mustelina, though 

 in dealing with particular colonies some subvarietal nomencla- 

 ture may eventually be needed. 



A. mustelina with its several forms already mentioned does 

 not extend southeastwardly beyond Lihue. From there to the 

 end of the range it is replaced high on the ridge by two quite 

 diverse races: A. m. lymaniana, an invariably sinistral shell, 

 which connects with mustelina through the forms called sor- 

 dida and napus; and A. concavospira, a dextral form of rather 

 lighter structure, with the outlines of the spire usually more 

 concave. 



A. concavospira is the terminal member of the series south- 

 eastward ; and although in some colonies there is an approach 

 to the mustelina (multilineata or napus) shape and coloring, 

 yet the differentiation as typically developed may be sufficient 



