Dolichopodidae. 353 



The proboscis is a little protruding; it and the oral aperture are 

 slightly larger in the female than in the male; the maxillary palpi are 

 large, squamiform, oval. Thorax rectangular and somewhat long; 

 behind, in front of the scutellum, there is a distinct, flat or slightly 

 concave declining area; postscutellum rather large. Acrostichal bristles 

 uniserial, few in number; there are six long dorsocentral bristles; 

 lacustris (non Danish) has, according to Mik (Jahresber. k. k. Akad. 

 Gymn. Wien, 1878, 8) seven dorsocentrals, and no small hairs in 

 front; further a humeral bristle, and a pair of weaker, a posthumeral, 

 two notopleural, a præsutural, three supraalar and a postalar bristle, 

 all well developed ; only few and very small hairs on the front part 

 of the disc; the scutellum has six, or (in non Danish species) four 

 marginal bristles (gen. AUoeoneurus Mik). The propleura have long 

 hairs, but no prothoracic bristles; the mesopleura are in front, just 

 behind the base of the front coxæ, prolonged downwards into a 

 strong spine. Abdomen somewhat long, about cylindrical; in the male 

 there are six dorsal segments of about the same length ; the fifth has 

 on each side at the hind margin an excision, or more correctly, an 

 impression, so that the hind margin appears somewhat excised (as in 

 some species of Hydrophorus)^ and the sides of the segment are pro- 

 longed downwards, meeting in the middle on the ventral side; the 

 seventh segment is small and quite hidden; there are four normal 

 ventral segments, the first as usual very short; behind the fourth 

 segment meet the sides of the fifth dorsal segment; the following 

 ventral segments are folded up and hidden by the hypopygium, they 

 form together with the lower side parts of the fifth dorsal segment a 

 sort of cavity for the reception of the hypopygium ; this latter {virens) 

 is short and rounded, but broad, robust and somewhat knob-like; it 

 is not imbedded, but lies closely pressed to the end of abdomen, 

 directed downwards and forwards; the eighth segment is a large 

 plate, covering almost the whole left side of the hypopygium ; the 

 hypopygium has below small, triangular, somewhat knob-like ventral 

 lobes; there are also two pairs of curved, complicated inner lamellæ 

 with dilated ends; the outer lamellæ have a broad, somewhat tri- 

 angular or crescent-shaped basal part, from its dorsal side issues a 

 long filament with long hairs; the basal parts are somewhat united 

 in the middle. In foreign species the outer lamellæ may be more 

 lamelliform, or on the contrary quite filiform, without broad base. In 

 the female there are five visible abdominal segments. The abdominal 

 segments have hindmarginal bristles, which are however small, except 

 on the first segment; in lacustris the bristles are stronger according 

 to Mik 1. c. There are dot-like impressions at the sides on the second 



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