190 [August, 



edge of the last abdominal segment. Its size and form varies greatly, 

 from a small and insignificant pnpilla to a long finger-like and con- 

 spicuous process. In some species the frons of the female is relatively 

 narrower (longer) than in the male, the costa too may be longer than 

 in the male, but the converse, I think, never happens. Sex, again, 

 occasionally influences the relative proportion of the costal divisions, 

 the tendency being for the second and third divisions in the female insect 

 to be lengthened without a corresponding lengthening of the first 

 division. Then the proboscis of the female is occasionally excessively 

 large aiid prominent, but that of the male is always small and incon- 

 spicuous. On the other hand, the third joint of the antenna? and the 

 palpi may be greatly exaggerated in the male, both in size and form, 

 without any corresponding chnnge in those of the female. A peculiar 

 form of the first abdominal segment, in which it is much scooped out 

 in the middle and unusually deep at the sides, overla[)ping the second 

 segment at the latter site, is present in a few species, as concin?ia, 

 crassicornis, ahdominalis, and to a less extent in one or two others. 

 This peculiarity is most pronounced in the female, the result being 

 that some of them have the second abdominal segment much length- 

 ened, a character usually confined to the males. 



G-ROUP I. 

 Frons without a median furrow. All the frontal bristles pointing 

 upwards (backwards), including the two in the middle just above the 

 base of the antennae Long distinct spines on the tibiae in addition 

 to the apical spurs. 



1 (47) Second thicJc vein forked. 



2 (If?) Only three distinct f}i>n reinx, the fourtli vein either absent, or verij iudis- 



tinct, or abbreviated. In lugubris 9 it is fairly distinct and complete. 

 Tibial spines always small and weak, the front tibise carry one 

 spine, the middle tibiae a pair in the upper third, and the hind tibiae 

 one at the junction of the upper and middle thirds. 



3 (4) (5) Palpi extraordinarily large, at least in Ihe male, curving round in 



front of the head. 



S . Thorax, abdomen, and halteres black ; scutellum with two 

 bristles only ; costa reaching beyond the middle, fringe very short ; 

 male hypopygium large and complex, anal protuberance minute and 

 hairy ; legs blackish-brown, long and slender. Very scarce ; taken 

 in the autumn. 



1^ mm.~ pal posa, Zett. 



4 (3) (5) Palpi narrow, straight, and cylindrical. 



(J 9 . Thorax, abdomen, and halteres black ; scutellum with 



