BRITISH FLIES 



Fig. 30. — Tlicveua anmilata ?. 



10. 



Fig. 31. — Oxyara pulehdla $. x lOA. 



(fig. 16), and is most commonly closed either at tlie wiiigmargin (when 

 it may vary in the same species as to being open or closed), as in 

 Thcrcva (fig. 30), or near the 

 wingmargin, as in Oxyrcra 

 (fig. 31), or it may he closed 

 near the wing base, as in Em - 

 'pis (fig. 32), or may become 

 ol)solete, as in Dolichopus (fig. 

 29), and in these latter cases 

 the venation and the antenme 



indicate the stepping stones to the ATHEiiiCEiiA ; discal cell almost always 

 present, thongh luit obvious in some Em^ndm and in all the subsequent 



families. Alula and axillary 

 incision well developed as a 

 rule, though sometimes obsolete. 

 Wing - membrane frequently 

 ribbed or rippled or merely 

 rumpled, being conspicuously 

 rib1)ed in some of the Strati- 

 omyidoi, and rippled or ribbed in the Tabanida:, Nemestrinidm, Cyrtidcc 

 (slightly), Boinhylida:., Therevida: (slightly), Mydaidce, and Asilidm, Init 

 not in the Lcptidce or Scenopi- 

 nidce, though exceptions may 

 occur, as I am una1:)le to trace 

 anything of the kind in the 

 genus Nemotdus and in some 

 species of Diodria. Squamge of 

 very varied development; the 

 alar pair being usually moder- 

 ately developed, but small in the Cydidce and rather small in some Asilidm, 

 while they are difficult to see in the Bomhylinm and the Nemestrinidcc, 

 well developed in the Thercvidcc, and moderate to large in the Tabanidce ; 

 thoracal squamte very frequently absent, or only indicated by the mem- 

 brane of the frenum, in the Lcptidce, Nemestrinidcc, Bomhylidcc, Therevidce, 

 Mydaidce, Scenopinidce, Apioceridcc, Asilidce, and some of the Stratiomyidw, 

 but large and conspicuous and rather upraised in the Tabanidcc, and 

 enormous and depressed in the Cyrtidcv. 



Pubescence soft and equal in the Eremocileta, as there is no trace of 

 long distinct hairs or bristly hairs or anything approaching to a bristle, 

 unless of such a structural nature as the thoracic spines of Ephip)2num, 

 the scutellar spines of Beris, Stratiomys, etc., or the femoral serration of 

 Xylomyia, etc., though the pubescence of the Leptidce is usually more rigid 

 than that of any of the Stratiomyidw ; in the Tromoptera (Bomhylidce and 

 Therevidoi) strong bristly hairs often occur on the sides of the thorax or 

 on the margin of the scutellum, and some of these hairs represent or form 



Fig. ■i-2.—Em]ds Intea S- X 10*- 



