DASTPOOONINAE 



ROBBER FLIES OF THE WORLD 



75 



Text-Figure 11. — Pattern of distribution of the genus Laphystia Loew. 



with a few short setae apically. The front is short, pol- 

 linose, with considerable pile laterally but without 

 bristles. The vertex deeply excavated, the whole front 

 and vertex distinctly though only moderately divergent ; 

 the ocellarium is large, wide, with moderately sloping 

 sides, pollinose and bearing between the ocelli 4 or 5 

 pairs of short, erect, stiff hairs or rarely 1 or 2 bristles. 

 Eye facets centrally enlarged. 



Thorax : The thorax is minutely appressed pubescent. 

 The mesonotal length is twice the height. Pile of mes- 

 onotum characteristically minute, appressed, and 

 curled setate; in some species there are also abundant, 

 long, fine hairs. Acrostical bristles poorly differ- 

 entiated. The mesonotal pile remains equally short 

 posteriorly and appressed. The type of genus displays 

 the following complement of lateral bristles: no hu- 

 meral, 2 notopleural, 2 supraalar, 2 to 4 postalar, and 

 no scutellar. In Lyphystia gigantella Loew the lateral 

 bristles are much longer and stouter, and there are 1 

 notopleural, 4 supraalar, no postalar, and no scutellar 

 bristles. Scutellum moderately thick, convex, largely 

 shining or wholly micropubescent, with short, flat ap- 

 pressed pile. Propleuron anteroventrally with a tuft of 

 abundant, fine pile, the anterior collar with stiff hairs 

 only; posterior propleuron with numerous, stiff hairs, 



almost bristly. The upper sternopleuron has a few, fine 

 hairs. Upper and posterior mesopleuron, upper ptero- 

 pleuron, and posterior hypopleuron with numerous, 

 long, fine hairs. Metapleuron with a vertical band of 

 very long hairs, the upper elements almost bristlelike. 

 Metanotal slopes micropubescent only, lateral and ven- 

 tral metasternum pilose, the latter forming a wide, 

 chitinized, isolated, pubescent band, the postmetacoxal 

 area membranous ; tegula pubescent only. 



Legs: The legs are moderately stout; the femora 

 are densely, short, appressed setate on all sides includ- 

 ing the ventral surface, to which may be added a few, 

 fine, rather long, slender, ventral hairs at the base; 

 the ventral pile varies from short and appressed to 

 long, copious and erect. The following complement of 

 mostly short and weak bristles is present: hind femur 

 with 1 at the base ventrolaterally, a minute bristle 

 dorsally on either side at the apex, a somewhat longer 

 one on either side subapically ; its tibia with 2 extreme- 

 ly weak small dorsal, 4 somewhat larger dorsolateral 

 and 4 longer, stout and well developed ventrolateral, 

 besides 2 other short basal bristles; apex with 2 dorsal, 

 1 lateral, 2 medial, and 3 or 4 ventral bristles ; base of 

 tibia narrow, the apex nearly twice as wide; the ven- 

 tral surface has a copious fringe of fine erect hair ; no 



