African PhJehotomic Diptera. 289 



H(Bmatopota pallidimarginata, sp. n. 



? . — Length (10 specimens) 6 to 9"2 mm. ; width of 

 ]ioa(l 2 to 3 mm. ; width of front at vertex just under 1 to 

 V'2 mm. ; length of wing 6"4 to 9'25 mm. 



Dark brown or clove-brown species, with conspicuous pale 

 hind margins to the abdominal segments and dark brown 

 strongly marked wings. — Dorsum of thorax with usual grey 

 longitudinal stripes ; light markings in wings clearly defined 

 and rather coarse, usual three rosettes present, apical sinuous 

 inark in some specimens distinctly bifurcate, but outer ramus 

 often reduced to one or two ill-defined light spots ; legs dark 

 brown to clove-brown, femora greyish clove-brown, tibice with 

 dull cinnamon-coloured bands, often indistinct, especially on 

 front tibice, latter with a single narrow and more or less ill-, 

 defined band close to base, middle and hind tibia each with 

 two bands. 



Head : front rather broad, dark brown, its sides diverging 

 below, in well-preserved specimens extreme lateral margins 

 and an edging surrounding lateral froutal spots light grey, a 

 darker brown partly divided median blotch sometimes 

 distinguishable on flattened upper border of vertex; face 

 and jowls light grey, area between lower inner margin of eye 

 and antenna on each side more or less brownish or speckled 

 with brown ; frontal callus dark sepia, moderately deep, 

 especially on each side, extending from eye to eye, but upper 

 lateral angles rounded off, upper margin more or less exca- 

 vated on each side of middle line, lower margin excavated 

 above antennae ; a small clove-bi'own spot often but not 

 always distinguishable in middle line below callus and above 

 antennae ; lateral frontal spots usually large, conspicuous, 

 clove-brown, and in contact wiih eyes, sometimes trans- 

 versely elongate, median frontal spot apparently wanting ; 

 palpi Isabella-coloured or mouse-grey, clothed on outer side 

 with black or blackish hair, terminal joint moderately 

 elongate ; first and second joints of antenna Vandyke-brown, 

 first joint short and not incrassate, slightly greyish pollinose, 

 upper angle of second joint moderately produced, third joint 

 clove-brown, slightly lighter at extreme base, basal portion 

 but little expanded, of nearly uniform depth and barely half 

 as deep again as last three annuli, latter short and deep^ 

 conspicuously flattened from side to side, terminal annnlus 

 blunt at tip, scarcely as long as two preceding annuli taken 

 together. Thorax: dorsum with extremely slender yellowish 

 grey median stripe, which reaches hind margin, and a. con- 

 tinuation of which is sometimes visible on scutellum ; 

 Ann. (d- Mag. N. Hist. Ser. 8. Vol. ii. 20 



