445 



veins and costa without visible setae or with very short setae. Female 

 genitalia similar. Male forceps nearly or quite as long as anal valve, 

 stout, uniformly converging on both margins to subacute apex, black 

 pointed ; anal valve short, posterior margin acuately rounded, broadest 

 near mid-point. 



Distribution : — Island of Hawaii — Kilanea, near Volcano, 

 4000 ft. elevation, Angnst 21, 1917 (W. M. GifFard) ; Kan 

 Eoad, January 16, 1017 (Giffard) ; Kahukn, January 15^ 

 1917 (Giffard) ; Kilanea, June 27, 1917 (0. H. Swezey), on 

 ohia lehua; Niulii, May 22, 1917 (Swezey). 



This appears to be closely related to T. ioJani but never- 

 theless not a derivative of it. It is more probably a corelated 

 derivative form of the ancestor of both. It seems to be limited 

 to the Island of Hawaii. Large individuals of T. iohud, equal- 

 ling in size this present species, occur on Oahu but these 

 differ sharply in male genitalia, costal setae and other minor 

 characters. 



Genus Kuwayama Crawford. 



The chief distinguishing characteristic of this genus is the 

 absence of genal cones, the genae beneath the antennal sockets 

 being more or less roundly swollen but not produced into coni- 

 cal processes as in Tr'ioza. The form of the genae in this sub- 

 family appears to be not at all fixed but varies more readily 

 than wing characters and some others. For this reason, it 

 seems certain that the species placed in this genus from various 

 countries of the world do not represent a common origin at 

 all, but independent or parallel evolution toward the same end. 



The three species of this genus, native to these Islands, 

 seem almost certainly to have been derived from some Trioza 

 species, probably T. ohiacola or an ancestral type preceding it. 



