172 BIBIONID^E. 



(in B. mard it is always distinctly longer, often twice as long). 

 Halteres black. 



Length 5 millim. 



Described from a single male from Darjiling taken in November, 

 1910, by Mr. D'Abreu. 



Type in the Indian Museum. 



This species is intermediate between B. marci, L., and B. obscuri- 

 pennis, Meij. From the former it is distinguished by the black, 

 not dark brown pubescence ; the shortness of the basal part 

 of the 3rd longitudinal vein, and the incrassation of the hind 

 metatarsus. Minor differences are the lesser incrassation of the 

 hind femora, the greater incrassation of the hind tibiae and the 

 pale grey wings, as contrasted with the quite whitish wings of 

 B. marci. When placed by the side of a specimen of mard, these 

 differences appear sufficiently distinctive. 



From B. obscuripennis, Meij., it differs by its smaller size and 

 clearer wings and in the structure of the hind metatarsus, which 

 in de Meijere's species is not distinctly incrassated and is twice 

 the length of the following joint. 



126. Bibio abdominalis, Brun. 



Bibio abdominalis, Brunetti, Rec. Ind. Mus. iv, p. 276 (1911). 

 c? $ . Head wholly black ; vertex very small, shining black, 

 with small distinct ocellar triangle. Eyes (which are densely 

 pubescent in the male with very dark brown or nearly black hair), 

 contiguous from vertex to antennae, the frontal triangle very 

 small. Antennae and palpi wholly black, moderately pubescent. 

 Thorax shining black, closely pubescent ; a fan-like bunch of 

 hairs in front of, and another one below, the root of the wing. 

 Scutellum and metanotum shining black, the former with long 

 soft black hairs on the posterior margin, with a tendency to curl 

 forwards ; metanotum bare. Abdomen shining black in male, 

 with close long black pubescence ; belly similar ; genital organs 

 confined in a hard squarish segment-like case. In the female the 

 abdomen is normally wholly reddish yellow, with minute sparse 

 black pubescence ; belly similar ; genital organs apparently 

 comprised in a flat elevation on the underside of the last 

 abdominal segment.* Legs shining black, anterior femora with 

 dense black hair, hind pair with the hair much sparser ; tibiae and 

 tarsi moderately pubescent. Wings dark grey in male, a little 

 blackish in female, in both sexes somewhat iridescent in certain 

 lights ; costal cell and stigma brownish ; veins dark brown. The 

 basal section of the 3rd longitudinal vein is almost exactly equal 



* In the type male and female, which still remain united, both abdomens 

 are considerably stretched out, as though the insects in life had endeavoured 

 to separate themselves, jet no extension of any part of the male genitalia can 

 be seen. There is a small thick rounded organ between the two abdomen 

 tips of the same red colour as the female abdomen, but it is nut obvious to 

 which abdomen it really belongs. 



