﻿THE ENTOMOLOGICAL MAüAZINE, Vol. III. Pt. Ill & IV. 129 



Length — lo mm. 



Hab. 一 Bonin Islands (Ogasawarajima), one female specimen 

 collected by Prof. S. Matsumura at Chichijima (20, VIII, 

 1905). 



Norn. Jap. — Toge-hirataabu. 



Hiratana Mats. (n. 



Much resembles Melanostoma Schin., but differs from it in 

 the following points ： 



Antennae longer, the 3rd joint broader, twice as long as the 

 1st and 2nd taken together, arists near the base, nearly at one 

 third part of the whole-length, naked. The touched portion of the 

 compound eyes of the male much longer than the vertex, vertex 

 long triangular, the upper ocellus much separated from the lower 

 ones, while in Melanestoma being situated in equilateral. Wings 

 much longer than the abdomen and brorder, venation more resem- 

 bles that of the Syrphus, 1st and 2nd posterior cells being in the 

 same level at the margin. Abdomen in both sexes oblong, broader 

 than the thorax, very flat. Legs moderate, the hind legs being 

 much longer than the intermediate pair. The behabior is the same 

 as Melanostoma Schin., and it may most probably be aphidivorous. 



Genotype — Hiratana 4-guttula Mats. 



丄. Hiratana 4-guttula Mats. (PI. L. fig. 15 



Journ. Coll. Agr. Sapporo, vol. IV, Syrphus 4-guttulus 

 Mats. p. 79, 191 1. 



cf Aeneous, with a bluish tinge. Face black, grayish pruinous, 

 except the middle tubercle, with pale yellowish hairs ； vertical 

 triangle shining, above with fuscous hairs ； antennae brownish, the 

 3rd joint beneath and the lower parts of the following joints, 

 yellowish, airsta yellowish, at the apex scarcely infuscated ； antennal- 

 process at the margin yellowish. Proboscis brownish. Thorax and 

 scutellum pale yellowish pubescent. Wirifs hyaline, scarcely in- 

 fuscated, veins fuscous, stigma fulvous. Calypteres grayish, at the 

 margin yellowish, halteres pale fulvous, its head being somewhat 



