9. MICROCHRYSA 191 



Chlorosia) is exactly synonymous with Microchrysa Loew, though I might have 

 added that M. polita is the type of Microchrysa and M. pallipes{=flavicornis) is the 

 type of Chlorosia, but I do not think that these two species will ever be generically 

 separated. 



TaUe of Species. 



1 (2) AntenusB and legs mainly blackish. 1 j^olita. 



2 (1) Antennae and legs mainly yellowish ; smaller species. 



3 (4) Abdomen in both sexes and frons of female brilliant greenish. 



2 fiavicornis. 



4 (3) Abdomen in both sexes and frons of female shining blackish. 



3 cyaneiventris. 



1. M. polita Linne. Antennse not at all yellowish at the base. Legs 

 mainly blackish. 



A common small bright green fly. 



S . Frons triangular, rather small, shining black, and bearing short rather dense 

 decumbent pale pubescence except on the depressed middle channel. _ Face 

 small, almost flat, shining green, and bearing fairly abundant but incon- 

 spicuous slightly upturned pale pubescence ; the narrow sides of the mouth 

 and the very small jowls with a very short pale ciliation ; back of the head 

 , so much hollowed out that it is not visible at all in profile ; vertex rather 

 raised, shining blackish green, and bearing very short blackish pubescence ; 

 proboscis brownish orange to blackish ; palpi small but just visible, blackish. 

 Eyes large, appearing to touch for a long distance but actually the vertical 

 triangle extends down a long way in a narrow point as is usually evidenced 

 by its short blackish pubescence ; the eyes are bare, but the facets on the 

 larger upper part are considerably larger than those on the smaller lower part, 

 and the contrast is so abrupt and conspicuous across the eye as to leave the 

 upper part slightly bulging. Antennae small, dull dark brownish ; two basal 

 joints with short brown bristly hairs ; third joint with four indistinct annula- 

 tions ; arista not quite apical, thin, and longer than the antennae. 



Thorax and scutellum all brilliant green, with usually a shade of blue, 

 thickly but finely punctate, and clothed all over the disc with extremely 

 dense but very short erect black pubescence, but towards the sides the 

 pubescence becomes rather longer, softer, and greyish ; the pubescence in 

 spite of its density does not afl^ect the brilliancy of the ground colour ; 

 pubescence on the pleurae slightly longer and pale brownish yellow, but there 

 is a large bare depressed polished space on the front part of the mesopleura^ 

 for the reception of the front femora. 



Abdomen brilliant green but not quite so bright as the thorax and usually 

 with a less bluish tint, slightly wider than the thorax and about as long, being 

 rather longer than broad; disc of the second, third, and fourth segments 

 densely and coarsely punctate and bearing an exti'emely dense very short 

 black (in side-lights greyish) pubescence, and consequently the brightness on 

 this part is diminished, but on the basal segments there is a longer pale 

 brownish inconspicuous pubescence ; the bright sides and the fifth segment 

 are less i^unctate and bear a rather sparse tiny pubescence which is more_ or 

 less obviously pale. Belly bright blackish green, all punctate, and bearing 

 very short inconsiiicuous pale pubescence. Genitalia dull orange, protruding 

 from about the middle sixth of the end of the fifth abdominal segment, and 

 bearing a pair of short orange upper lamelhe. 



Legs mainly blackish ; coxa? and trochanters tipped with brownish orange ; 

 all femora orange at the tip (front pair broadly), and the anterior tibiae all 

 orange except usually for a large obscurely darkened splash on most of the 

 apical three-fifths (least distinct on the front tibiae) ; hind tibiai orange about 

 the basal quarter and at the extreme tip ; all tarsi orange, with the last four 



