604 DERMATINA 



strong apical spur or two or three apical bristly spines ; tarsi witli plantar bristles 

 only. Pulvilli two, moderately large and distinct, but the empodium absent and 

 apparently without even any bristle in its place ; claws long. 



Wings with a peculiar complex venation, which is distinct from that of any other 

 family in the Diptera though somewhat approached by the distinctly cha^tophorous 

 ApioceridcB and by some Asilince near Erax, Avhile some of its less obvious pecul- 

 iarities occur in the Scenopinidoe. Subcostal vein extremely long, with the radial 

 vein and the up])er branch of the cubital fork always curving up into it before 

 its tip (fig. 331) ; the lower branch of the cubital fork also curving up almost parallel 

 with the upper branch, and often also ending in the subcostal vein, while even the 

 upper veinlet from the discal cell (and sometimes two veinlets, as in fig. 332), after 

 leaving the discal cell curves up in a similar way (almost parallel with the wing- 

 margin) and sometimes ends in the subcostal vein ; the upper branch of 

 the postical vein also curves up almost parallel with (but well away from) the 

 wingmargin, so that altogether the curving up of the veins and their running almost 

 parallel with the hind and apical margins of the wing, are most striking ; in addition 

 the peculiarity of the two branches of the cubital fork (and sometimes also the vein- 

 lets from the discal cell) reaching the wingmargin before the wing-tip is almost un- 

 paralleled ; pra^furca exceedingly short ; discal cell always present, but remarkably 

 long and narrow and often of trapezoid or most irregular shape, in no way bounded 

 on the lower margin by any portion of the postical vein, and usually appearing to 

 emit one veinlet only which curves up towards (and sometimes runs into) the sub- 

 costal vein, and when the (normally) second veinlet is distinct it curves up parallel 



Fig. 332. — Mitrodetus dentitarsis S- x 8. 



with the first but appears to arise from the closed fourth posterior cell, while the 

 (normally) third veinlet bends sharply downwards (unless apparently altogether 

 absent) and closes the (normally) fourth posterior cell (fig. 334) ; upper branch of the 

 postical fork often running into the discal cell at the end of the latter and never 

 running clear to the wingmargin, but always causing a long closed (normally fourth) 

 posterior cell to lie under and parallel with the discal cell ; basal cells long, the 

 upper one being most unusually long through the discal cross-vein being placed near 

 the tip of the discal cell (as in the Nemestrinidch) and near the end of the stem of 

 the cubital vein, but sometimes the discal cross-vein ties the longitudinal veins so 

 tightly together that the upper margin of the discal cell is hitched up until it 

 touches the cubital vein at the place where the latter is pulled down ; ambient vein 

 complete though sometimes very faint ; lower cross-vein always present though 

 short and placed close to the base of the upper branch of the postical fork ; posterior 

 cells three (the normal second, third, and fifth being united as in fig. 335), or four 

 (the normal second and third being united as in fig. 334 or the third and fifth as 

 in fig. 332) ; anal cell closed before the wingmargin ; wing-membrane ribbed or 

 rumpled, bare ; alulae often large, and overlapping the scutellum when the wings 

 are folded. Squamae (alar) present, but small and usually without any fringe, or 

 sometimes (in at least Jli/das) rather large and bearing a stiff very coarse marginal 

 fringe ; thoracal pair absent. 



This family has long been well recognisad through its peculiar venation 

 and antennse, though for a long time the distinctly chsetophorous Apioccrinm 

 were incorrectly associated with it, but it is now almost certain that these 

 latter are more closely related to the Asilince. Brauer was of opinion that 



