16 Orthorrhapha brachycera. 



lum witliout bristles. On the pleura there is a hairy stripe from the 

 humerus to the wing-root, and from this one goes down to the front 

 coxæ, and another stretches down the hind margin of the mesopleura 

 and then bends in an angle along the lower margin of the meso- 

 pleuron; the hairy stripes are sometimes not fully developed; the 

 metapleura have long hairs and especially a vertical row of long, thin 

 hairs; hypopleura without long hairs. Metathorax is rather distinct, 

 on the dorsal side it is short, on the ventral side there is a large meta- 

 sternura, the space between the latter and the hind coxæ is membranous. 

 Abdomen is long and somewhat slender, generally more slender in 

 the male than in the female; it consists of eight segments; the first 

 dorsal segment is short; on the ventral side the first segment is also 

 short and somewhat weakly chitinised; at the front of the second 

 segment there is a small, transverse, chitinised plate on each side in 

 the connecting membrane; the last dorsal segment is short, the last 

 ventral segment is quite hidden and only represented by a very small 

 chitinised plate, and in the female it is quite wanting so that there 

 are only seven ventral segments, The male genitalia have a construc- 

 tion very different from that found in Leptogaster; above there is a 

 large, somewhat cupshaped plate, formed like a ninth dorsal segment, 

 its hind margin is excised, the hind corners thus forming two pointed 

 prominences; in the excision are two small, free styles; below this 

 plate are the lower forceps, the arms of which are thick at the base, 

 hook-formed and of very complicated shape, they are tw^o-branched 

 with an inner styliform branch; between and below the forceps is 

 a ventral plate, forming, like the dorsal plate, as a ninth ventral 

 segment. The female genitalia resemble in some points the male 

 genitalia; above there is a short dorsal plate which bends down on 

 the sides, forming the half of a ring; at its slightly excised hind margin 

 there are, as in the male, two sjnall styles; below there is a some- 

 what clasp-shaped ventral plate (perhaps in reality the eighth ventral 

 plate); at the apex, below the dorsal styles, there are two small styles, 

 these four styles thus forming an ovipositor. Legs not strong, the 

 hind legs the longest ; the hind tibiæ often somewhat thickened at the 

 apex, the hind metatarsi always large, sometimes considerably thickened. 

 On the femora and tibiæ there are some strong, more or less spine- 

 like bristles of different strength in the different species and sometimes 

 wanting on the anterior femora; apical spurs are also present; further 

 there are some scattered long and thin hairs on the ventral side 

 of the femora and hind tibiæ and fmally there is a dense fringe of 

 short hairs along the ventral side of the hind femora and tibiæ; the 

 pubescence of the legs is specially dense on the ventral apical part 



