NO. I ACHATINELLA APEXFULVA DIXON— WELCH 23 



nite color forms at different elevations. Moreover, a color form be- 

 longing to a definite area is separated from the color form of an- 

 other area by a region containing shells which have an intermediate 

 color pattern or a mixture of the color patterns of the areas on 

 either side of it. The extent of these intermediate localities has not 

 yet been well determined, for the work in the Koolau Range is still 

 in the pioneer stage because of the rareness of the shells, the rough- 

 ness of the terrain, and the vast extent of the Koolau Range. The 

 shells in a border region between two areas may have a color pattern 

 which is a mixture of those of an upper and lower area and is also 

 intermediate between those of the shells occurring on parallel ridges 

 on either side of the area. From a study of the carefully collected 

 regions of the Koolau Range and a study of the collection as a 

 whole, so that the trend in the differentiation of Achatmella is de- 

 termined, Achatinella sensu strictu is grouped into the following six 

 species: i, A. lorata Ferussac; 2, A. apexfulva Dixon; 3, A. tnrbini- 

 formis Gulick; 4, A. concavospira Pfeififer; 5, A. decora Ferussac; 6, 

 A. mustelina Mighels. This paper concerns only A. apexfulva; a 

 discussion of species i, 3, 4, and 5 will be reserved for future papers. 

 Subspecific groups will be used in this paper to group together 

 the lower orders of forms of A. apexfulva^ as is done for A. mustelina 

 (Welch, 1938). The term "variety" will also denote that a particular 

 form is closely related to a particular subspecies but has not enough 

 distinctive characters to warrant its separation into a definite sub- 

 species. All varieties will be numbered var. i, var. 2, etc. 



TAXONOMY 



SYNOPSIS OF THE SUBSPECIES OF ACHATINELLA APEXFULVA DIXON 



The following synopsis is purely an artificial grouping of forms 

 that seem to be similar. No great detail will be attempted because 

 so few really distinct characters exist beyond the shape and color of 

 the embryonic whorls and size of the shells. The color pattern of the 

 postembryonic whorls in some regions is of use, but very often it is 

 of little aid since the same pattern may occur again and again in widely 

 separated forms. Unless otherwise stated the color pattern of the 

 shell is the color of the last two postembryonic whorls. 



A. Embryonic whorls bicolored. First embryonic whorl a dark color 

 (black, gray, light brown), remaining embryonic whorls white, cream 

 buff, or some shade of yellowish white. The dark band or line usually 

 fades out, on the first quarter or first half of the second embryonic 

 whorl, into the ground color or into a light yellowish-white band or 



