Diptera: Nemoccra vera, N.anomala and Ercinochaeta. 455 



Hapalothricc (f has contiguous eyes; I coiüd not ascertain the 

 existence of bisection in the dry speciraens which I examined. 



Tlie color of the eyes of ßlepharocera capitata, which I took 

 down from living speciraens was reddish-green on the npper half, 

 and pnrple on the lower one. 



The eyes of all the known species of the Blepharoceridae are 

 finely pubescent. but some of them have a covering of longer hairs 

 besides (Hapalothri,v and the lower portion of the eyes of Bibio- 

 cephalaj. Three large ocelli are present (the majority of the Nem. 

 Vera have iio ocelli). The antennae are comparatively short and 

 without verticils. Xo pulvilli and a rudimentary empodium. In its 

 pulvilliform ungues, Hapalothrix has a character unique among 

 Diptera. 



The wings of the known Blepharoceridae differ from the wings 

 of all the other Diptera in the presence, besides the ordinary vena- 

 tion, of a net of crease-like lines which extend over the whole sur- 

 face. The wings have moreover a peculiar iridescence (not unlike 

 that of Simnliian). The axillary excision is replaced here by a chi- 

 tinous knot, which I have observed in all the species; the alula, an- 

 titegnla and tegula are absent, or rudimentary. An interrupted lon- 

 gitudinal vein, between the fourth vein and the large fork of the fifth, 

 distinguishes four among the eight genera of the family. The 

 ground-pattern of the venation is more or less the same in all the 

 genera, only the number of longitudinal veins between the first and 

 the fourth vein is gradually diminishing from Bibiocephala and 

 Agathon, which have three such veins, to Lipone^ira and Blepha- 

 rocera, which have two, Äpistomyia and Paltostoma one, and Ham- 

 matorhina — none. 



The larvae of the Blepharoceridae (those of Liponeura and 

 Paltostoma have been described in detail) are very aberrant, and 

 cannot be compared to aiiy other larvae oi Diptera. They are sub- 

 ject to the same condition of life as those of Simidium, the life in 

 rapidly running waters; from this condition arises the necessity of 

 precautions against the danger of being carried away by the current, 

 and in the present instance the problem is solved by adaptations 

 quite ditferent from those of the larvae of Simididae, and apparently 

 capablc of resisting a much strenger current. The larvae live in 

 rapid mountain-streams, and are found on slimy stones under water, 

 clinging to them by means of six suctorial discs, one on the under- 

 side of the thorax, the othcrs on the ventral segments; they move 

 slowly on the stones by means of tliese discs, and lind thcir food 

 among the slimy matter (l)ewitz, Berl. Ent. Z. 1881, p. 64, says 



