126 



THE DIPTEKA BEACHYCERA Ot^ TASMANIA, 



54. Hilar OP us. Gen. nov. (Figs. 42 and 43.) 

 Small or medium sized flies resembling H/'Iara, but dis- 

 tinguished by the mediastinal vein being straight, incom- 

 plete, and not reaching the costa ; anterior tarsi in the 

 male with the first joint dilated as in Hi/ara. 



Head small, narrower than the thorax. Eyes separated 

 in both sexes. Proboscis varying in length from about 

 the height of head to twice the height of head. Antenna? 

 about the same length, or a little longer than the head, 

 the first joint either short or fairly long, the second always 

 short, the third about as long as the first two joints to- 

 gether, either broad or slender, and terminated by a style 

 which is from a quarter to half its length. Thorax rather 

 arched, with bristles as in Hilar a, and, in the male, some- 

 times bearing dense pubescence; metapleural bristles 

 wanting. Abdomen slender in the male, broader in the 

 female, in the former sex sometimes bearing lateral tufts 

 of stiff bristles. Legs either moderately short or elongated, 

 the first joint of anterior tarsi in the male always con- 

 spicuously dilated, and the femora and tibire in the same 

 Fex may be densely hairy. Wings with the mediastinal 

 vein nearly straight, and not reaching the costa ; cubital 

 fork either short or fairly long ; discal cell with three 

 issuing veinlets, which are all complete ; anal vein w^eak, 

 and not reaching the wing-margin. 



The species belonging to this genus resemble those of 

 Hilara, both in appearance and in habits, but are distin- 

 guished by the straight, incomplete mediastinal jrein, 

 which does not reach the costa. From Erniiis the genus is 

 distinguished by the greatly dilated front tarsi of the 

 male, and by the absence of metapleural bristles. From the 

 Tasmania n species of Empi.^ it may be further distinguish- 

 ed by the shorter proboscis. Four species are at present 

 known, which seem to fall into two natural groups, as 

 given below. 



Fig. 42. Right front leg of (a) H ihiropua pall idif urea, 

 (b) //. ii'xjrinianux. (c) //. pcreyrinii^, (d) II. cclnnatus. 



