NO. I ACHATINELLA APEXFULVA DIXON — WELCH 201 



differentiation. The contrast between lowland streaked and highland 

 banded patterns is very marked. On some ridges as many as 7 or 8 

 distinct color races are found (see pi. 2, figs. 24-30; pi. 3, figs. 1-8, 

 12-18, for examples of forms occurring on three ridge complexes). 



North of Kawailoa Gulch no particular zoning is known to occur 

 today in ridge complex 19. But in Gulick's day there must have been a 

 division between A. a. napus and the darker reddish-brown forms that 

 occur today in areas iii, 112, 113, 114. 



3. SIZE 



Thirteen ridge complexes (2-6, 8-9, 13-15, 17, 18, and 20, fig. 8, 

 p. 195) show size increase in the majority of localities with increase 

 of elevation. The smaller lowland shells, with the exception of area 2, 

 are in zones I and II and are usually 17-f or i8-|- mm., with here and 

 there a locality with i9-(- shells. In area 2 all forms are in zone III, 

 but all the lowest localities have small i8-f- or 17+ shells, similar 

 in size to those usually found in zone II, while the highest locality 

 contains 194- shells. In all the remaining 12 ridge complexes showing 

 size increase in zone III, the shells are 19-f- or 20-f- mm. Although 

 there is a contrast between zones II and III the increase in size is 

 not a gradual one. The highest localities do not contain the largest 

 shells. Northwest of ridge complex 7, 19+ shells occur above 20 -H 

 shells in many localities. In ridge complex 8, 20 -f- shells occur above 

 21 4- shells. Ridge complex 3, area 12 (table 2), has i8-|- shells 

 and appears on figure 8 (p. 195) to be at a higher elevation than 

 the 194- shells. However, the shells were collected on a small spur 

 ridge of ridge complex 3, probably at a lower elevation in Nuuanu 

 than the 19 -|- shells. The exact extent of the locality is uncertain. 



The 18-I- sinistral shells from area 62?, ridge complex 14 (table 2), 

 are reported from the same locality as the larger 19-t- dextral shells, 

 and are separated because of the size difference. If both dextrals and 

 sinistrals are lumped together, the mean length is 18.0 mm. The 

 locality was plotted 13 years after being collected and probably 

 represents two localities, one of dextral and one of sinistral shells. 

 On figure 8, ridge complex 14, 184- shells are plotted above 194- 

 shells, which may be an error. Whether the dextral or sinistral shells 

 occur in separate localities, or one above the other, is of no great 

 importance. The small 184- shells are of interest because they are 

 another exception to the general trend. 



Out of the seven ridge complexes not showing altitudinal size 

 variation, two can be disregarded. One of these, ridge complex 19, is 



