PLATYURA. 65 



a curve near its junction with the prsebrachijil transverse, and is very 

 slightly curved from thence to its end, which is very little in front of 

 the tip of the wing ; its fore fork is more or less oblique ; subapical 

 emerging from the cubital at half the length of the ■wing, forked at one- 

 third of its length from thence to its end, its fore fork ending at very 

 little behind the tip of the wing ; subanal forked at one-third of the 

 length of the wing, its hind foi'k curved liindward, and diverging much 

 from the fore one ; anal extending to the hind border ; subaxillary not 

 reaching the hind border ; humeral veinlet near the base ; areolcts thir- 

 teen, — the humeral, the radical, the subcostal, the radial, the probrachial, 

 which is united to the pobrachial and shortened tovv'ards the tip, the 

 two cubital, three externo-medial, the anal, the axillary, and the sub- 

 axillary. Posterior margin forming a slight and very acute angle at 

 twice the length of the humeral areolet from the l)ase. Halteres short. 

 Abdomen somewhat depressed, about thrice longer than the thorax. 

 Legs rather long and slender ; tih'ns without spines, ilieir spurs short. 

 Male. Abdomen nearly linear and cylindrical. Tera. Abdomen elongate- 

 obclavate or subfusiform. 



These flies are similar to the Mj/cetophilce in their habits ; most 

 of the species inhabit woods, and their larvae feed on fungi. The 

 species may be grouped thus : — 



a. Fork of the cubital vein joining the radial. Species 1. 

 a a. Eork of the cubital vein joining the costal. 

 b. Fork of the cubital vein rather long. 



c. Fork of the cubital vein curved. Species 2-4. 

 c c. Fork of the cubital vein straight. Species .5, 6. 

 b b. Fork of the cubital vein short. 

 c. Wings spotted. Species 7-10. 

 c c. Wings not spotted. Species 11-14. 



1. marginata, Meig. Zw. i. 232. 1 (1818); Mcq. Nigra, palpis 

 pedibusque testaceis, alls subcinereis macula disculi marginibusque ob- 

 scurioribus, halteribus tibiisque fulvis, tarsis fuscis ; Fceni. abdominis 

 fasciis ferrugineis. Long. 3-0—4 ; alar. 5i-6 lin. 



Black, shining. Palpi tawny. Antennae a little longer than the 

 thorax. Wings greyish, clouded with grey towards the tips and along 

 the hind border, and with a slight brownish s|)ot at the base of the 

 subapical vein. Halteres tawny. Abdomen long. Legs testaceous ; 

 tibia; tawny; tarsi brown. Fem. Wings with the discal brownish spot 

 almost obsolete. Fore borders of the abdominal segments ferruginous. 



Not common. (E.) 



3. atrata, F. S. A. 16. 3 (1805); Meig.; Mcq. Nigra, alis cine- 

 reis macula aulicu siihupicalifusca, halteribus testaceis, femoribus tibiisque 

 obscure testaceis, illis basi nigris. Long. 3 ; alar. 5 Hn. 



Blacli, shining. . Antenna) stout, a little shorter than the thorax. 

 Wings grey, with a disused subapical brown spot in front. Halteres 



VOL. IV. K 



