Dolichopodidae. 153 



metatarsi always without bristles. There are two claws, two pulvilli, 

 and a somewhat comb-shaped empodium with long bristles below. 

 In the males the pulvilli of the front tarsi are (generally) more or 

 less enlarged. Wings of common shape, somewhat small ; the media- 

 stinal vein terminating in the subcostal vein; the discai vein with a 

 small bend, its apical part converging towards the cubital vein, the 

 first posterior cell narrowly open; the posterior cross-vein lies behind 

 the middle; the anal vein reaches near to the margin. Axillary lobe 

 of medium size. The discai bend lies on a distinct convexity. Squamulæ 

 with a somewhat large angulary lobe bearing a fringe of long hairs 

 at the margin, between the long hairs, at the base, are short, dense 

 hairs; the inner part of the squamulæ has short hairs. 



The genus is nearly allied to Dolichopus and Hercostomus (as 

 well as to Poecilobothrus) ; from the former it is distinguished by 

 the hind metatarsi having no bristles, and from both by the epistoma 

 with clypeus reaching far down, to or almost to the lower margin of 

 the eyes (Fig. 2), and also by the shape of the epistoma, which is 

 widened downwards, especially in the males. 



Of the developmental stages, which, as far as I am aware, have 

 hitherto not been known, I have examined the pupa of T. insignis. 

 It is brownish yellow ; on the front side of the head there are a pair 

 of approximated, short, triangular spines, and below them another 

 pair of very small spines or knobs; further down there is on each 

 side a narrow keel; the antennal sheaths are not discernible as such, 

 but the mentioned spines answer no doubt to the apices of the an- 

 tennal joints, and the keel to the arista ; to each side of the upper 

 spines is a short, somewhat strong hair. On the disc of thorax are 

 three very short hairs in an oblique line on each side; at the front 

 end of thorax are two closely approximated, long (2 mm), attenuated 

 spiracular tubes, which are brownish yellow. On the second to eighth 

 abdominal segment there is above, at the hind margin, a transverse 

 row of very short and small spines, and the abdomen terminates with 

 a pair of small knobs below. The sheaths of the legs reach to the 

 end of abdomen. 



The larva forms an oval cocoon of sand , of 8 to 9 mm's 

 length, and rather solid. It is formed of grains of sand, and as 

 the wall is not thin, 1 mm or more in thickness, this may be 

 the reason, why the spiracular tubes of the pupa are so long. Dr. 

 Wesenberg Lund, to whom I am indebted for the pupa and cocoons, 

 found these at the Danish hydrobiological station at Fure Sø on ^^/s 

 and bred one of them on ^^/s. The cocoons were found in the sand 

 at the border of the lake, and consequently the larva must live there, 



