TACHINA. 31 



nearly twice the length of the second ; fourth and fifth very short ; sixth 

 very minutely pubescent, stout for one-fourth of the length from the 

 base, more than twice the length of the third. Wings grey, with a 

 brownish tinge at the base and in front ; costal vein ending at a short 

 distance in front of the tip of the wing ; subcostal vein ending at less 

 than one-third of the length ; mediastinal vein ending at less than half 

 of the length ; radial vein ending at about five-sixths of the length ; 

 cubital vein ending very near the costal ; praebrachial vein forming a 

 very obtuse and not sharply-defined angle at its flexure, straight from 

 thence to the tip ; discal transverse vein with two distinct curves, parted 

 by much less than its length from the flexure of the prsebrachial, and 

 by half its length from the border. Alulae grey. Abdomen elongate 

 oval, black. 



Not common. (E.) 



27. tremula, L. S. N. iii. c. 152 (1767) ; F. ; Schr. F. B. ; Gmel. ; 

 Fal. ; Mcq.; Zett. grossa, Schr. I. A. Nigra, cinereo-subtomentosa, 

 capite albo, alis albidis, venis luteis fulvo subnebulosis, alulis albis, ab- 

 domine longi-ovato nigro. Long. 4 ; alar. 8 lin. 



Frontalia deep black, broad, linear ; bristles of the front descending 

 along one-fourth of the face ; face slightly oblique ; facialia with bristles 

 along one-sixth of the length ; epistoma not prominent ; eyes hairy. 

 Antennas almost reaching the epistoma ; first and second joints ferru- 

 ginous at the tips ; second very much longer than deep ; third sub- 

 linear, slightly truncated, nearly twice the length of the second ; fourth 

 and fifth short ; sixth very minutely pubescent, stout for one-fourth of 

 the length, full twice the length of the third. Wings whitish, slightly 

 tawny along the luteous veins ; costal vein ciliated, with a spine at the 

 tip of the subcostal, ending at some distance in front of the tip of the 

 wing ; subcostal vein ending at much beyond one-third of the length ; 

 mediastinal vein ending at much beyond half of the length ; radial vein 

 ending at beyond five-sixths of the length ; cubital vein ending at near 

 the end of the costal ; praabrachial vein forming a very obtuse angle at 

 its flexure, hardly curved inward from thence to the tip ; discal trans- 

 verse vein with two very indistinct curves, parted by hardly less than 

 its length from the flexure of the prasbrachial, and by much less from 

 the border. Abdomen black. 



'Not common. (E.) 



28. inter cedens, n. Nigra, cano-tomentosa, capite argenteo, 

 thorace nigro-quadrivittato, alls cinereis basi testaceis, alulis flavo-albis, 

 abdomine subelliptico, segmentorum marginibus posticis nigris. Long. 

 4 ; alar. 8 lin. 



Frontalia deep black, widening in front ; face vertical ; bristles of 

 the front descending to one-sixth of the face ; facialia bristly for one- 

 sixth of the length ; epistoma not prominent ; eyes bare. Antennas 

 almost reaching the epistoma ; second joint much longer than deep ; 



