200 



INSECTS OF SAMOA. 



anterior orbitals ; arista very short haired ; vibrissae single, situated behind 

 anterior line of eyes, and very widely separated ; thorax with 1-2 pairs of 

 dorsocentrals, four scutellars, one mesopleural and one sternopleural ; all tibiae 

 with a preapical dorsal bristle, very short and fine on hind pair ; first wing-vein 

 bare ; ultimate section of fourth vein about five times as long as penultimate 

 section. 



In the key given by Melander and Argo {loc. cit., p. 4) this genus cannot be 

 carried further than (2), since it can be placed in neither of the groups segregated 

 by the characters listed, one having reclinate orbitals and cruciate interfrontals, 

 and the other having either proclinate or convergent anterior orbitals. 



Genotype, Isoclusia samoaensis, sp. n. 



1. Isoclusia samoaensis, sp. n. 



Shining tawny yellow, face whitish-yellow, with white dust ; frons 

 brownish, orbits narrowly margined with whitish dust ; antennae and palpi 

 testaceous yellow ; legs entirely yellow ; wings hyaline, with a fuscous cloud at 

 tip from apex of second vein, evanescent posteriorly. 



Frons dull, subquadrate, interfrontalia bare, anterior orbital with a very 

 slight curve at apex, about half as long as posterior orbital ; eyes almost round, 

 bare ; third antennal segment about 1-5 as long as wide, rounded at apex ; 

 arista slender, about 1 -5 as long as width of anterior margin of frons ; cheek 

 about as high as width of third antennal segment ; face slightly convex. 

 Thorax with four series of intradorsocentral hairs, presutural bristle well 

 developed, and no distinct prescutellar acrostichals ; scutellar bristles subequal, 

 disc bare. Legs normal, front femur with a series of posteroventral bristles, 

 becoming longer apically. Outer cross-vein of wing set over 1-5 its own length 

 from apex of fifth vein ; ultimate section of fourth vein about five times as 

 long as penultimate section, not noticeably curved forward apically. 



Length, 3 mm. 



Savaii : Safune, type and paratype $, 13.V.1924 (Bryan). Type in the 

 Bishop Museum, Honolulu. 



2. Isoclusia hyalipennis, sp. n. 



c^. Very similar in all respects to the foregoing species, and agreeing in 

 colour and general structure, but with no trace of an apical dark mark on the 



