453 Osten Sachen: on the characters of tlie three divisions of 



The larva oi Scatojyse lias been desciibed by liouchc, Dufour 

 and Perris; the two bitter took it for ampliipneustic, but it is a 

 question whcthcr Bouclie was not right in taking für spiracles the 

 niue projections on the sides of tlie body, one on the thoracic scgnient 

 and eight on the abdominal ones. The pupa does not shed the larva- 

 skin, bat reniains in it, enierging with the front part only (some 

 Uirvae oi Ceratopogon, occurring nnder the bark of trces, do the same). 



Simulidae. The principal characters which exclude this faniily 

 from the Nemocera vera are: the holoptic head of the male; tlic 

 bisected and bicolored eyes of the same sex; the structure of the 

 antennae, which are comparatively short, attennated towards the tip, 

 with Short, transverse, closely compressed joints, clothed with an 

 almost microscopic pubescence, without any verticillate hairs; the 

 Short, but streng and stout legs, with broad, flattened tibiae, and 

 long, likewise broad and flattened, metatarsi, which are almost as 

 long as the tibiae. i) Among other characters I shall notice vcry 

 minute spurs on the four posterior tibiae (generally not mentioned in 

 descriptions); the tarsal joints 2 — 5 which are very small in comparison 

 with the very large first Joint ; the fourth tarsal Joint bilobed as in Orphne- 

 phila^ Diamesa and some species oi Chironomus and Ceratopogon; 

 the fifth Joint generally at an angle to the fourth (even in living specimens) ; 

 ungues very small in the male, a little longer in the female; empodia 

 rudimentary; body thickset, comparable to Psychoda among the Ne- 

 7nocera vera; no ocelli; wings broad, iridescent, glabrous, with streng 

 veins on the anterior, and evanescent ones on the posterior part; no 

 ambient vein; anal angle large, axillary incision very little marked, 

 but containing a chitinous knot, resembling that in the Biepharoce- 

 ridae; alula small, antitegula rather large, both with long, delicate 



i) With their long front metatarsi Simidium execute peculiar 

 motions, for the first time described by Macquart, Dipt. du Nord, 

 Vol. I: „Lorsqu'elles sont posecs sur une feuille, leurs tarses ant^rieurs 

 s'appnient dans toute leur longueur sur le plan de position; ils sont 

 dans un mouvement continuel de tatonnement et paraissent servir trös 

 peu k marcher. C'est cette habitude qui a fait donner par Linne le 

 nom de Ctdex reptans k l'espece la plus connue, Comrne ces insectes 

 habitent ordinairement les buissons situ^s sons les arbres et qu'ils y 

 recueillent avec la trompe les sucs repandus sur les plantes, et particu- 

 lierement ceux produits par les Pucerons, leurs tarses fönt les fonctions 

 de palpes; ils servent ä reconnaitre cet aliment et on les croirait i'or- 

 gane d'un sens superieur au toucher." 



I reproduce this passage because the Observation about the food 

 of Simidium seems to be nevv, and because Macquart's Dipt. du 

 Nord etc. are not often consulted by dipterologists. 



