206 



same amount of collecting- is done in other districts as has 

 been (lone in the vicinity of Kilanea, is nearly certain. Little 

 or no Delphacid collecting has been done in Kohala or Kona 

 and very little in Hamakna. Oahn has not yet been exhausted, 

 and the" other Islands have only been worked in a few localities. 



One thing which the tables show up very distinctly, which 

 is not likely to be greatly modiiied by more extensive collect- 

 ing, is the" high percentage of single-island endeniism. Out 

 of'^the 78 species and subspecies recorded 65 (83.37c) are 

 confined to single islands, 9 (11.57o) are common to two isl- 

 ands, 3 (3.87c) to three islands and 1 (1.37o) to five islands. 

 In comparing the two gro-ups the AJoliae, with 84.6 7^, is 

 slightlv above the Lcialohae (with 80.87) in single-island 

 endeniism and below (.06 to 1.5) it in two-island endeniism; 

 considering that the LciaJohae are all macropterous and most 

 of the Alohae brachyi>terous, one might have expected a 

 greater dift'erence. It indicates, if the relative antiquity of 

 the two groups be not considered, thai the power of fiight, 

 while reducing topographical evolution, had not influenced 

 geograiihical evolution ; that is to say, the power of flight had 

 been sufiicient to enable species to move about freely on an 

 island, Imt had not been sufiicient to enable them to pass 

 freely from island to island. 



Kauai has only one endemic Alohae. whilst it has 5 Lei- 

 alohae; Oaliu stands with 2-1: and 8, and Hawaii with 8 and 

 4, nearly the same proportion as the total species in each isl- 

 and, a natural conditicni when the number common to two or 

 more islands is so small. This might indicate that the immi- 

 grant ancestors of the AJoliae, arriving from the south' or 

 southeast, landed upon one of the more southeasterly islands 

 and only a few have been able to reach the more isolated nor'- 

 western island of Kauai. The fact that only two species of 

 the genus Aloha are known outside of Oahu, and one of these 

 the ubiquitous A. ipomoeae, may be due to our igiiorance, luit 

 it lends support to the idea that Oahu may have been the 

 original ]i()int of colonization and the center of distribution. 

 Tlic Lciftl()]i(((' are better flyers and so a greater proportion 

 has reached Kauai. But why evolution in Kauai should 

 have been more active among the Le'ialohae than among the 

 Alohae is not evident. 



In the table of two-island endeniism we find that Kauai 

 has one species common with Oahu and one with Molokai, 



