DIOCTRIA. 59 



Epistoma flat, broad, clothed with shinini^- down on each side, beset 

 with a few bristles ia front. Eyes generally green, rarely violet ; fore 

 part flat, composed of large facets. Three ocelli on the crown. Pro- 

 boscis porrect, short, almost horizontal. Labrum conical, very short. 

 Lingua subulate, flat, clothed towards the tip with short velvet-like 

 retracted hairs, as long as the labium. Maxilla; subulate, flat, jiointed, 

 almost as long as the lingua. Palpi short, cylinchical, truncated, 

 bristly. Labium bristly, arched beneath, channelled above, small 

 in front. Antennce porrect, h-jointed, not stylate, seated on a tu- 

 bercle, closely approximate at the base, curved, diverging, longer 

 than the head ; first and second joints bristly ; flrst joint cylindri- 

 cal ; second shorter than the first ; almost cyathiforui ; third long, 

 compressed; fourth and fifth very short, forming an obtuse tip. 

 Thorax oval, almost bare, often striped on the back, and gilded 

 or silvery on each side. Wings lanceolate, narrow, obtuse, vei-y 

 finely pubescent ; mediastinal areolet open. Alidse small, entire. 

 Halteres micovered. Abdomen with 7 segments, bare, almost cylin- 

 drical, sometimes marked with yellow on each side ; flrst segment 

 broader and more arched than the following. Legs slender, slightly 

 bristly or quite bare ; femora and tibite straight ; hinder tibiaj finely 

 fringed with hairs ; fore tibia; slightly hairy by the spurs ; hind tarsi 

 slightly clavate. Onychia conspicuous. 



These flies inhabit meadows, trees, and bushes, during the 

 summer, aud are more abundant than those of the preceding 

 genus ; they feed chiefly ou small B'lptera ; some species prey 

 upon llijmenoptera. 



1. oelandica, L. s. n. ii. lOOS. 1.5 (1763); Fb. ; Shr. ; Gfr. ; 

 Gm. ; ]\lg. ; LI. ; Fin. ; Mq. ; Zll. ; Ztt. ; Lw. Nigra, thorace albido- 

 quadri\dttato, ulis nigricantibus, pedibus rufis, tibiis apice tnrsisque 

 nigris. Long. 6-7 ; alar. 10-12 lin. 



Black, shining, clothed wdth black hairs. Head with a white 

 covering beneath, and on each side of the front. Epistoma convex, 

 beset with yellow bristles. Palpi clothed with long black hairs. First 

 and second and the base of the third joint of the antennae clothed 

 with black hairs. Thorax with 2 whitish stripes on the back, and with 

 an oblique yellowish white stripe on each side. Tf^ings blackish ; discs 

 of the areolets paler towards the tips and along the hind border ; veins 

 black. Halteres yeUow. Legs red, clothed with short tawny hairs ; 

 tibise and tarsi armed with tawny spines ; tarsi and tips of the tibia; 

 black ; claws tawny, with black tips ; onychia yellow. 



Generally distributed. (E. S.) 



2. cothurnata, Mg. zw. ii. 244. 6 (1820). — Meiyenii, Sd. ent. 

 141. 26. Atra, thorace cinereo-trivittato, lateribus abdominisqne seg- 

 mentorum marginibus posticis ferruaincis, alis limpidis, pedibus fulvis, 

 tibiis apices versus tarsisque pici'is. Long. 7-y : alar. ^?> lin. 



