PSILOCEPIIALA. 303 



Table of Species. 



1. Femora dark brown ; all tibiae and tarsi 



pale yellowish brown ; (thorax pre- 

 sumably unstriped) ulbina, Wied., p. 303. 



Femora black or blackish, with or Avith- 

 out white or silvery shimmer 2. 



2. Front tibiae blackish brown, or at least 



distinctly darker than posterior pairs. 3. 

 All tibiae (presumably) uniformly pale, w „ 3Q5 



at most tips darker . ^ Kr5b / 3oa 



3. Thorax dull black, with two grey l M ' > * 



stripes ; emarginations of abdominal 



segments reddisb or yellowish indica, Big., p. 304. 



Thorax dark grey, one median darker 

 stripe ; abdominal emarginations not 

 coloured ; eyes absolutely contiguous, ceylonica, Krbb., p. 304. 



241. Psilocephala albina, Wied. 



Thereva albina, Wiedemann, Zool. Mag. i, pt. 3, p. 3 (1819) ; id., 



Auss. Zweifl. i, p. 233 (1828). 

 Pdlocephala albina, Krober, Ent. Mitteil. Berl. i, p. 252 (1912). 



<5 . " Head with sil very-white tomentum, extreme margins of: 

 frontal triangle appearing dark brown • in certain lights can be 

 seen two dark parallel stripes, fading away downwards towards 

 the antennae; antennae blackish' brown, sparsely beset with black 

 bristles; palpi and proboscis long, with snow-white hairs; back 

 of head with whitish-grey tomentum and white hairs ; orbital 

 bristles black. Thorax dull grey, with yellow and grey pubescence ; 

 scutellum like thorax, with black bristles ; sides of thorax blackish, 

 grey-dusted and with grey hairs. Abdomen black, dull, with 

 somewhat strong silvery glistening and long whitish hairs, which 

 in certain lights, especially on the last segment, appear yellow ; 

 2nd to 4th segments with yellowish hind margins. Venter 

 blackish, with gre3 r pubescence, with yellowish hind margins to 

 segments ; genital lamellae reddish yellow, with black and whitish- 

 yellow hairs. Legs •. coxae blackish, white-haired; femora dark 

 brown, covered with white pubescence ; tibiae and tarsi pale 

 yellowish brown, tips darkened. Wings hyaline, veins weak, 

 yellowish, 4th posterior cell closed ; halteres blackish brown, tips 

 of clubs whitish. length, 9 mm. Type S from Java, in the 

 Vienna Museum. 



2 . " Frons narrow, dull blackish brown ; epistorne shining 

 silvery white ; two dull black spots near each other above the 

 antennae, outlined with white ; antenna and back of head as in J . 

 Thorax and scutellum black, with very sparse yellowish and grey 

 hairs ; sides of thorax blackish, with silvery-white tomentum and 

 white hairs. Abdomen dull blackish brown ; each segment bears 

 an ill-defined triangular silver-white spot on each side on the hind 



* These two species are almost certain to be identical. No characters of 

 differential value can be selected from Krober's description of bis unique type. 



