296 THEllEAaD.!). 



moderately large ; in $ long, sliining, with a circlet of spines at 

 tip as in many ANTUEACiNiE aud Asilid.'e. 



Legs rather long and thin, vvitli bristles of moderate size ; 

 anterior tibia3 with two or three longitudinal rows of bristles, 

 hind tibiae with four rows ; all tibiae with a circlet of apical spines ; 

 pulvilli two or none, empodiiun reduced to a thin bristle or 

 absent. 



Wings \v\t\\ a ratlier uniform venation ; 1st and auxiliary veins 

 not extending much beyond middle of \^ing; pra3furoa beginning 

 at some distance before base of discal cell ; 2nd vein simple ; 3rd 

 forked, the fork generally including the wing-tip : upper branch of 

 4th vein forked ; 5th vein forked ; anal vein present and generally 

 axillary vein also ; anterior cross-vein placed at about middle of 

 discal cell, which latter is always present ; posterior cross-vein 

 present. Two submarginal, five posterior cells, 4th sometimes 

 closed. " Squamae with only the alar pair developed, but they 

 are rather large aud peculiarly folded, so that the strongly-defined 

 margin is angled about the middle, and gives the impression of 

 there being two ])airs of squamaj." ( Verrall.) 



Life-histoi-g not definitely known, altbougli on several occasions 

 specimens have been alleged to have been bred from Lepidopterous 

 larvse (SpJiina-, Trlphama, Alencis). Larvae very elongate, cylin- 

 drical, very active, vermiform, with exserted head ; body apparently 

 of 19 or 20 segments, probably caused by subdivision of true seg- 

 ments, amphipneustic, with prothoi'acic spiracles on 2nd body- 

 segment, and a posterior pair at sides of 4th segment from tip : 

 last segment, small; no pseudopods, but a few fine bi'istles on first 

 three body-segments. Pupa free, bearing anteunal sheaths on 

 front side of head. The larvae are found in the earth or in sand, 

 sometimes in decaying wood, occasionally in fungi, turnips, or 

 dung; tliey are said to be carnivorous. The perfect insects occur 

 chiefly in shady places, on bushes and low-gi-owing plants. 

 Walker and Williston stating that they prey on other insects, 

 although no sufficiently attested c^se of the kind is known; and 

 they are also stated to be cannibalistic in captivity. Beling and 

 Eouclic have supplied most of our knowledge on this subject. 



The Theuktid.e occur in all ])arts of the world, but are most 

 numerous in Europe and North America. They are easily 

 recognised by their usually furry appearance, subconical shape, 

 and unmarked wings, and can be distinguished from their nearest 

 allies, the BoMBYLiiDiE, by the five posterior cells and the ])resence 

 of the posterior cross-vein. Many species are objects of great 

 beauty; amongst Indian representatives of the family may be 

 noted PsilocepJiala sequa, Walk., which is covered with nearly 

 snow-white pubescence and performs aerial dances in many places. 

 Although the Indian species (except one or two Psilocephala) 

 appear quite distinct, the family is noted for the exceedingly close 

 aifinity of some species, characters which at first sight would 

 appear trivial being constant and of quite good specific value. 



