60 Orlhorrhapha brachycera. 



the same length, the sixth is small, the seventh is likewise small and 

 forms the peduncle of the hypopygium; on the ventral side the second 

 and third sternites are normal, the following are strongly incised 

 posteriorly, the largest part of them being membranous, or there are 

 here no chitinised sternites; this part is folded up groove-like between 

 the dorsal segments, and the hypopygium is laid up in this groove; 

 the seventh segment has a chitinised sternite, lying at the ventral 

 base of the hypopygium. The hypopygium is exposed, somewhat 

 pedunculated, curved up under the venter; it is generally large, and 

 has as a rule slightly projecting posterior ventral lobes, rarely these are 

 longer and styliform, or on the contrary broad and projecting down- 

 wards; also the middle ventral lobes may be more or less projecting 

 backwards. The inner lamellæ are more or less curved, generally 

 the median are thin, the lateral more or less dilated. The median 

 dorsal appendage is hook-shaped. The outer lamellæ are blade- or 

 shovel-shaped, smaller or larger, and may vary somewhat in shape; 

 they are generally divided into teeth at the end, and bear curved 

 hairs at the apical and ventral margin. In the female there are five 

 normal abdominal segments, the second to fifth being of about the 

 same length, and with normal sternites; further there are three hidden 

 segments, and an ovipositor terminating with some (6) small spines 

 above, and below them two small styles. Abdomen has conspicuous 

 dot-like impressions at the side margin of the second, third and fourth 

 segments. The abdominal segments have hindmarginal bristles. Legs 

 somewhat long, coxæ a little elongated. In the males the front or 

 middle tarsi are sometimes adorned in different ways, one or more 

 joints being dilated, plumed and differently coloured; in rare cases it 

 may be the hind tarsi which are adorned {remipes) ; in other cases 

 the front tarsi in the males may be bearded with short hairs. The 

 hind tibiæ are always a little (more or less) thicker in the male than 

 in the female, sometimes to a considerable degree. The legs are 

 haired with short hairs; the coxæ have bristles at the apex, generally 

 largest on the front coxæ; the middle coxæ have a bristle in the 

 middle on the front side near the outer edge, and the hind coxæ 

 have a bristle in the middle on the outside. There are one or more 

 preapical bristles towards the apex on the posterior femora, and 

 bristles on the tibiæ, which to some degree may afford speciflc 

 characters; the tibiæ have also apical or preapical bristles; the hind 

 metatarsus is of or about of the length of the second joint, rarely 

 considerably longer, and always has bristles. In the males the hind 

 femora sometimes bear a fringe of long hairs or cilia, rarely these are 

 found on all femora; sometimes the front tibiæ in the males bear a 



