﻿TABANIDAE — PART I. 125 



and extending from middle of front to ocellar region of vertex, which is slate- 

 grey ; upper portion of sides of face, except orbits, thinly clothed with whitish 

 hair, basi-occipital region and posterior orbits clothed with yellowish or whitish 

 hair ; palpi clove-brown ; first joint of antennae greyish clove-brown, second 

 joint greyish fawn-coloured, third joint cinnamon, large, broad at base. Thorax : 

 lateral borders of dorsum grey pollinose ; ground colour of pleurae and pectus 

 agreeing with that of dorsum, pleurae clothed with yellowish or whitish hair. 

 Abdomen : tergite of first segment with a large black blotch at base, extending 

 beyond scutellum but not reaching basal angles or hind margin ; hair on tergite 

 of first segment sometimes entirely ochreous, sometimes black on black blotch 

 and silvery-white on hind border ; tergites of second and third segments each 

 with a large, median, black spot, resting on or closely approximate to base of 

 segment in each case, and either not quite reaching hind margin or barely 

 extending beyond middle of segment ; spot on second segment the larger, and (at 

 least in case of type and para-type) bluntly triangular, with its apex directed 

 backwards, spot on third segment rounded or more or less quadrate in outline ; 

 black spots and adjacent area on second and third segments clothed in part with 

 minute black hairs ; tergites of fourth to sixth segments inclusive each with a 

 black transverse band at base, band on fourth segment in case of type contracted 

 towards each lateral extremity in such a way that the segment is ochraceous both 

 in front of and behind it ; hind borders of tergites of third to sixth segments 

 inclusive sometimes yellowish-grey pollinose, with median expansions which, on 

 fourth and fifth segments, may reach front margin ; tergite of seventh segment 

 wholly black, more or less yellowish-grey pollinose, and clothed with black hair 

 intermixed with orange-ochraceous hair ; ventral surface of abdomen buff or 

 cream-buff in front, black at distal extremity, third and fourth segments (except 

 hind borders) more or less burnt-umber-coloured (fourth segment sometimes 

 largely dark brown), hind borders of second, third, and fourth segments cream- 

 coloured, second segment and hind borders of two following segments clothed 

 with silvery-white, whitish, yellowish, or ochreous hair, lateral extremities of 

 hind borders of fifth and sixth segments clothed with ochre-yellow hair, third and 

 following segments, except as already stated, clothed mainly with minute, 

 appressed, black hairs. Squamae cream-coloured. Halter es : knobs seal-brown 

 on each of their broader faces, intervening area cream-coloured ; stalks buff. 

 Legs : coxae grey, clothed with yellowish or whitish hair ; femora clothed with 

 black hair ; upper surface of tibiae and tarsi clothed with minute, glistening, 

 whitish or yellowish hairs. 



Northern Rhodesia : Grwai River, March, 1911 (the late O. C. Silverlock). 



This species is dedicated to the memory of its discoverer, a young entomologist 

 in the service of the British South Africa Company, who, shortly after the 

 specimens described above were collected, unfortunately lost his life in the River 

 Zambesi, through the upsetting of his canoe by a hippopotamus. 



As indicated by the shape of the body, Dorcaloemus silverlocki is allied to 

 D. bicolor, Austen (in which the face is likewise short), more nearly than to any 

 other of its congeners yet described ; the present species can however at once be 

 distinguished from D. bicolor by the coloration of the abdomen, and of the hairy 



