164 STRATIOMYID.E 



TaUe of the Palcearctic Genera of Sargin^. 



1 (2) Second antennal joint lengthened on the inner side hke a thumb 

 inserted into the third joint (fig. 135). Ptecticus. 



Eyes of the male not toucMng. 



2 (1) Second antennal joint normal. 



3 (6) Eyes bare or almost so. 



4 (5) Elongate narrow species. 

 Eyes of the male not touching. Veinlets 



issuing from the discal cell distinct. 



7. Sargus. 



5 (4) Short and stout species. 

 Eyes of the male touching. Veinlets 



^ ^ , „ . , , .^ „ issuing from the discal cell very faint. 



* Fig. 135.— PSccdcits fcwcbn/cr 9 . ° -.r 



X 22. 9. MiCEOCHRYSA. 



6 (3) Eyes densely and conspicuously hairy. 

 Eyes of the male touching. Oblong species. Veinlets issuing from the 



discal cell rather indistinct. 8. Chloromyia. 



An attempt was made by Loew in 1855 to divide Sargus into two 

 genera, one with equidistant ocelli (Chrysonotus) and one with the front 

 ocellus remote from the other two (Sargus sensu stricto), and many authors 

 appear to have recognised the distinction but I have found myself unable 

 to do so. 



7. SARGUS. 



Sargus Fabricius, Entom. Syst. SuppL, 549, 566 (1798). 



Figure long and narrow. Middle-sized species of brilliant 

 metallic green colour. 



Head semig]obular, wider than the front part of the thorax and (wlien viewed 

 from in front) wider than deep, considerably excavated behind and attached to the 

 prothorax by a slender neck ; frons (in profile) occupying four-fifths of the distance 

 from the occiput to the upper mouth edge ; face rounded and slightly projecting 

 from the eyes though short and retreating, densely pubescent ; ocellar space always 

 and the part of the frons above it usually distinctly elevated, ocelli placed well 

 forward from the vertex, so that the foremost one is placed at nearly a quarter of the 

 length of the frons {Chrt/sonotus) or as much as two-fifths of the length {Sargim, 

 s. str.), and the front ocellus is slightly more remote from the other two than they are 

 from each other {Chrysonotus) or considerably so (Sargus). Eyes quite bare, dis- 

 tinctly separated by the frons in the male (fig. 136), and still more widely separated 

 in the female ; facets inconspicuously enlarged on the front part in the male. 

 Antennai short, placed (in profile) well below the middle of the head, and consequently 

 not so prominent at their base as the most prominent part of the frons ; second joint 

 cup-shaped, and the two basal joints bristly ; third joint transverse and but little 

 longer than the others, composed of four annulations of which the fourth is less bulky 

 than the others, and from the extreme dorsal base of which the long thin arista 

 arises • this arista is therefore distinctly not apical and is two or more times longer 

 than the antennae, and bears a few slight plumes about its base. 



Thorax rather long and narrow being rather contracted anteriorly, brilliantly 

 shining green, and bearing considerable though rather inconspicuous pubescence ; in 

 the male this pubescence is often of two very different lengths, there being a short 



* The faint annulations of tlie third joint are not shown in the drawing. 



