730 



ASILID^ 



Legs usually slender (not in D. atricajnlla) and with few conspicuous bristles 

 and only slight pubescence, though some bristles may be long and thin ; femora 

 usually rather thickened ; basal joint of the hind tarsi always rather stout and 

 sometimes conspicuously dilated. Pubescence on the anterior coxae rather long, 

 pale, and somewhat silky, but without any bristles ; anterior femora with a very few 

 long hairs beneath but hardly with bristles except some small subapical ones ; front 

 tibiae with about two (2-4) thin bristles beneath near the middle (but these bristles 

 varying in length and often very thin and inconspicuous), and about four (3-6) 

 postero-ventral bristles extending over nearly the whole length, and a few (3-4) very 

 small inconspicuous dorsal or slightly postero-dorsal ones ; middle femora sometimes 

 with a few anterior longer hairs or small bristles near the base, but more commonly 

 with only sparse soft pubescence ; middle tibiae with two or more long antero-dorsal 

 bristles and four or five postero-dorsal, and about four (2-4) ventral ; hind femora 

 with only a few antero-dorsal and postero-dorsal bristles near the base ; hind tibiae 

 with a few (2-6) dorsal bristles (very minute in B. atricapilla, etc.), and usually a 

 few (0-3) anterior, and sometimes some thin postero-ventral hairs which may easily 

 be overlooked ; all the femora have some short subapical bristles, and the hind 

 femora and tibiae bear on their postero-ventral surface an exceedingly fine brush-like 

 or furry pubescence which is rather conspicuous, and which in this felt-like form is 

 almost peculiar to Dioctria among the British Dasypogonince, and this furry 

 pubescence extends beneath the basal joint of the hind tarsi ; all the tibiae have a 

 terminal circlet of spines, and each of the four basal joints of the tarsi has a similar 

 circlet of six strong bristles, but the front tibiae have no terminal claw as in 

 Isopocion. Pul villi large, extending almost to the end of the long claws. 



Wings (fig. 400) proportionately long and broad ; small cross- vein present and 

 placed rather near the base of the discal cell ; all five posterior cells open, the 



Fig. 400. — Dioctria Baumhaueri. x 10. 



first, second, and sometimes fourth being almost equally so, but the fourth some- 

 times a little contracted ; anal cell not closed, but steadily narrowing until it is 

 nearly closed at the Avingmargin ; wing-membrane wrinkled. Squamae (alar) small, 

 with a thick margin on which there is a fringe ; thoracal pair bare, hardly more 

 than the frenum. Halteres with rather large knobs. 



This genus is distinguished by the absence of a front tibial claw, the 

 practical absence of any face-knob and the limitation of the face-beard to 

 the upper niouthmargin, the distinct stout antennal style, and the limited 

 chsetotaxy and absence of villosity. The best specific characters lie in 

 the shape of the antennal prominence, the length of the antennse, the 

 constitution of the face-beard, the stripes of tomentum on the pleurae, the 

 presence and distribution or entire absence of tomentum on the disc of 

 the thorax, and the form of the hind legs, but little value can be attached 

 to the colour of the face and legs and not much to the colour of the wings 

 and humeri. 



Dioctria is a rather large Palsearctic genus, nearly forty species being 

 known from that region, while seven (which I doubt being congeneric) are 

 recorded from North America, three from South America (including 

 perhaps our B. oelandicd), one (doubtful) from New Guinea, one from 

 Guadaloupe, and two or three from the Cape of Good Hope. D. hcgubris 

 of Jaennicke from Cuba has bristles on the hind margin of the thorax, 



