TRICHOCRRA. 271 



Male. Abdomen obtuse at the tip, witli rather short forceps. Fem. Ab- 

 domen with two short curved divergent anal styles. 



The larvae live in fungi, decayed wood, and decaying vegetables, 

 such as potatoes, turnips, and carrots. The body is cylindrical. 

 The head is oval, with two very short lateral lobes ; tlie tip of the 

 abdomen is much acuminated, and has tliree small conical points. 

 The flies are very numerous, and their habits are indicated by the 

 names of two of the species, for they live throngh the winter, and 

 resume their ascending and descending fliglit wdienever a thaw 

 occurs. The species may be grouped thus : — ■ 

 a. Fork of the first externo-medial vein short. Species 1. 

 a a. Fork of the first externo-medial vein long. 



b. Transverse veinlets of the wings not clouded. Species 2. 



b b. Transverse veinlets clouded with brown. Species 3. 



1. fuscata, Meg.; Meig. Zw. i. 212. 1 (1818); Mcq. ; Gim.; 

 Sttieg. ; Zett. — annidata? Meg.; Meig.; Mcq.; Stfeg. ; Perris ; Zett. 

 Lurlda, tJiorace vitta ciuerea, alls sublimpidis, vence externo-medudls 

 prima furca brevi, abdomine fasciis siibcme?'eis, tarsis fuscescentibus. 

 Long. 21-3 ; alar. 6-7 Un. 



Lurid. Antenna) blackish. Thorax toilh a r/reij dripe. Wings nearly 

 limpid ; fork of the first externo-medial vein short. Halteres testaceous, 

 with piceous knobs. Hind borders of the abdominal segments greyish. 

 Tarsi brownish. 



Generally distributed. (E. S. I.) 



2. hiemalis, D. G. Ins. vi. 360. 13 (1752); Latr. ; Lam.; :Meig. ; 

 Mcq. ; Zett. ; Gim. ; Curt. ; Staeg. ; Ross. (V.) — parva, Meig. ; Mcq. ; 

 Zett. ; Gim. ; Stseg. ; Ross. (V.) Nigra, alls sublimpidis, vence exlerno- 

 medialis prima furca longa, abdomine pedibnsque piceis, tarsis nigris. 

 Long. 3-3^ ; alar. 7-8 lin. 



Slack. TFings nearly limpid ; fork of the first externo-medial vein 

 long. Halteres testaceous, with piceous knobs. Abdomen piceous. Legs 

 piceous ; tarsi black. 



Generally distributed. (E. S. I.) Appears during the winter 

 when the weather is mild, and is gregarious in the air, and then 

 its movements are vertical, like those of many other Tqmlidce. 



3. regelationis, L. S. N. 2. 972. 21 (1703) ; F. ; Schr.; Gmel. ; 

 Meig. ; i\Ic(j;. ; Zett. ; Gim. ; StsEg. Lurida, vertice thoracisque disco 



fuscis, alls sublimpidis, ve7ia externo-medialis prima furca longa, venulis 

 transversisfusco-nubilis, tarsis fuscescentibus. Long. 3-4 ; alar. 7-9 lin. 



Dull lurid. Vertex and disc of the thorax hroicn. Wings nearly 

 limpid ; transverse veinlets slightly clouded with brown ; forh of the first 

 externo-medial vein long. Halteres pale testaceous, with piceous knobs. 

 Legs pale lurid ; tarsi brownish. 



Generally distributed. (E. S. I.) 



