76 Director s Annual Report. 



cent, from I and II. There are only two of the color- varieties 

 found in like proportion on a single genus of plants. These are 

 the color- varieties \^ and W, of which all the specimens were 

 found on lehua. 



The sixth group of color- varieties, as has been said, is very 

 closely related to A. bcllula. This group is represented by only 40 

 specimens, of which all but two came from sub-ridges XV-XVII. 

 This group is connedled with the three largest' groups by the fol- 

 lowing color-varieties : H with the first group, J with the second 

 group, and O with the fourth group. The third and fifth groups 

 are most nearly related to the second group. The seventh group 

 agrees in the color and markings of the last whorl with the 

 first, second and fifth groups ; and in the banded apex with the 

 fourth group. 



In this species it can be seen that isolation plays a greater 

 part than environment. 



In closing the writer wishes to express his thanks to Direcflor 

 William T. Brigham for naming several of the plants, on which 

 shells were found, and for many useful suggestions. Also to Rev. 

 E. W. Thwing for the loan of a valuable paper. 



^ 



