BIBIO. 167 



female the eyes are oval, much smaller, bare, separated by a very 

 broad flat frons, often nearly of half the width of the head ; three 

 ocelli on a small triangular distinct protuberance. Proboscis 

 moderately prominent, with thickened hairy labella ; palpi varying 

 in length, generally five-, but in some species four-jointed, the 1st 

 joint small, the 3rd often thickened. Antennce rather short and 

 comparatively stout, cylindrical, generally of ten joints, but in 

 some cases only nine ; the joints set rather closely together, the 



Fig. 17. Head of Bibio : a, front view of rf ft, side vie\ 

 c, front view of .* 



of 



last one rounded ; the whole antenna not much longer than 

 the head. Thorax much elevated, generally closely pubescent ; 

 scutellum small, semicircular. Abdomen elongate, conical; ot 

 seven or eight segments. G-enitalia consisting in male of a pair 

 of two-jointed claspers, the 2nd joint incurved, conical ; both 

 generally densely pubescent. In the female the short ovipositor 

 terminates in two small lamellae. Legs moderately long, robust, 

 hardly longer than in the brachycerous families ; the hinder pair 

 generally longer than the others ; fore femora usually thickened ; 

 fore tibiae prolonged into a stout, slightly curved spine, a smaller 

 adjacent spine not infrequently being present. Hind femora and 

 tibiae often incrassated distally, the latter with two small spurs at 

 the tip ; hind metatarsus shorter than the remaining four joints 

 taken together. Pulvilli, empodia, and claws well developed. 

 Wings of considerable size, broad, with the costal vein ending 

 before reaching the tip. Auxiliary and 1st longitudinal veins 

 present, the 2nd absent, the 3rd present, simple,t all these 

 ending in the costa between the middle and the tip of the wing. 



* In the figure eleven joints are incorrectly shown ; there should be, at 

 most, ten only. 



t As stated in the introduction to this family, it seems to me that the vein 

 referred to may be the 2nd longitudinal and not the 3rd. 1 follow custom, 

 however, in terming it the 3rd. Its place of origin, length, and forked 

 character in allied genera (Plecia, Aspistes) all resemble the usual nature 

 of the 2nd longitudinal rather than the 3rd. 



