70 LEPTID.'E. 



fiilvo, autennis ferriigineis, abdomine cinereo maculis trigouis nigris 

 uuivittato apice fulvo. femoribus anticis fusco-vittatis. Long. 3-|— 5 ; 

 alar. 8-11 lin. 



Cinereous. Epistoma slightly convex. Proboscis black, with a 

 cinereous covering, clothed with short black hairs. Palpi black, 

 clothed with long black haii's. Thorax with 3 brown stripes, thinly 

 clothed with tawny hairs. Wings colourless, with many large irregular 

 brown spots, which are darker and more confluent towords the fore border; 

 veins black. Halteres tawny, with brown knobs. Legs tawny, clothed 

 with short black hairs. Femora clothed with tawny hairs ; tarsi black 

 towards the tips. Mule. Head clothed with black hairs, hoary and 

 clothed with whitish hairs beneath. Anteunse black, cinereous at the 

 base. Abdomen tawny, clothed with tawny hairs, black at the base ; 

 3 rows of black spots along the back ; spots in the middle row large, 

 triangular ; 2 black bands near the tip ; underside with 3 black spots 

 and 2 black blands. Anterior femora black towards the base. Fern. 

 Head pale yellow, clothed with pale yellow hairs beneath. Antennae 

 ferruginous, cinereous at the base. Abdomen cinereous ; a transverse 

 black spot on the fore border of every segment whose hind border is 

 tawny. Fore femora striped with brown towards the base. 



Generally distributed. (E. S.) 



The female of tliis fly is gregarious, and attaches its eggs in 

 large clusters to boughs hanging over streams, and there re- 

 mains, and shortly dies. The cluster is generally pear-shaped, 

 and sometimes contains many thousands of dead flies, and con- 

 tinually receives accessions by new comers settling upon it. 

 When the larva is hatched it falls into the water, its future 

 residence ; it has a forked tail about one-third of the lengtli of 

 the body, and has the power of raising itscK in the water by an 

 incessant undulating motion in a vertical plane. 



2. marginata, Fb. s. i. ii. 413. 6 (1781); Gml. ; Mg. ; Mq. ; 

 Zw. ; Ztt. ; Grmtl. Cinerea, antennis nigris, alis fuscis ad costam 

 obscurioribus disco maculatis, abdominis segmentis cano-fasciatis, pedi- 

 bus nigris. Long. 4 ; alar. 8 lin. 



Grey, clothed with black hairs. Epistoma shghtly convex. Pro- 

 boscis and palpi black, the latter clothed with long black hairs. An- 

 tennae black. Wings dark brown along tioo-thirds of the fore border, 

 pale brown at the tips and along the Ivind border ; some almost colourless 

 spots in the disc; veins black. Halteres tawny, with black knobs. 

 Hind borders of the abdominal segments hoary. Legs black, clothed 

 with very short black hairs. 



Eare.' (E.) 



3. crassicornis, Hras. ; Pz. ! fn. cv. 10; LI.; Mg. ; Mq. ; Ztt. 

 — griseolu, Fin. Cincrca, subtus cana, antennis ferrugineis apice nigris. 



