,54 Annals of the South African Museum. 



ANASTOECHUS LEUCOSOMA, sp. nov., 9 



An elegant species of small size, distinct from any other owing to 

 the body being clothed entirely with long silvery hairs, without 

 distinct bristles even -on the abdomen, and by the vitreous wings, which 

 have a silvery basal comb. 



Type female, Bushmanland, Jackal's Water, October, 1911 (R. M. 

 Lightfoot) ; O'Okiep (Cape), November-December; a specimen from 

 Matjesfoiitein (Cape) is much larger, measuring 8'5 mm. in length. 

 The present species was named by Bigot Systoechus leiicosoma in M.S. ; 

 I have retained the very appropriate specific name. 



Length of body 5'5-6 - 5 mm. ; of wing expanse 13-16 mm. Head 

 black, but densely clothed with silvery scales at the hind border of the 

 eyes and on the sides of frons and face ; on the vertex only there is a 

 broad transverse black baud clothed with erect black hairs enclosing 

 the ocelli and extending from one eye to the other, like those of the 

 ocellar tubercle ; all the other hairs are silvery, long and dense, chiefly 

 on the upper part of the occiput and on the face ; there are no distinct 

 bristles ; the frons is twice as broad as the eye. Antennae entirely 

 black ; the first joint long and clothed with long, white hairs ; the 

 third joint linear, restricted to a long and thin petiole at the base, not 

 broader in the middle than the second joint, and less attenuated at 

 end. Proboscis as long as the body, 6-6'5 mm. long, thin, entirely 

 black ; palpi black, thin, with same Jong white hairs at the end. Thorax 

 short and rather arched above ; entirely clothed with long silvery hairs, 

 those of the disc being only slightly dark if viewed from the side or 

 from above ; there are 110 distinct bristles, the notopleural and postalar 

 ones being concealed within the fur, from which they cannot be distin- 

 guished. Scutellum entirely black, clothed like the thorax, and 

 likewise destitute of bristles. Squamae white, with pale yellowish 

 border and with argenteous fringe ; halteres yellowish. Abdomen 

 entirely black, with long hairs like those of thorax ; the bristles at 

 the hind border of the segments are thin and of the same colour as 

 the fur, from which they are not distinguishable ; venter black, 

 yellowish at end, with shorter white hairs ; the genitalia are destitute 

 of the usual tuft of hairs, but have two approximate lamellae with a 

 longitudinal fissure between them. Legs short and strong, with well- 

 developed spines of a white (not yellow, as in the other species) colour ; 

 they are clothed with broad silvery scales, which are developed chiefly 

 on the femora, but are abundant even on the tibiae. The femora are 

 black, those of the two anterior pairs with the apical half pale yellow 

 and those of the hind pair with the end yellow ; the anterior and middle 



