Specie a of African vSiinulii(lft\ 73 



in others on hexagonal plates. In one species — S. gihnpe.t, 

 Pomeroy — the membrane is covered with crescent-sliapcd 

 nodules arranged in rows. In three species which have 

 I)upje with four-branched fihiments the resemblance in 'tlic 

 arrangement of the chitin is remarkable, since one species 

 {S. bracteatuin, Coq.) is found in N. America, anotlier 

 [S. aureum. Fries) is a British species, and a third {S. aiireo- 

 simile, Pomeroy) is found in theKamernn, W. Africa. The 

 writer has not made any histological investigation into the 

 subject, and some considerable work needs to be done before 

 any definite; conclusion can be reached ; but from superficial 

 oliservation under a low power the characters seem to be 

 too important to be overlooked. 



In the following descriptions of new species the pnp?e 

 liave been correlated with the adults, by dissecting adult 

 males which were almost ready to emerge from the pu[)al 

 skin and comparing their genitalia with those of specimens 

 bred in the streams at tire same time and place. 



Simulium cervicornutum, sp. n. 

 (PI. III. fig. 3 ; PI. IV. fig. 3.) 



Male. — Length 1'5 mm. 



Antenna black, covered with a short greyish pubescenc •. 

 Thorax velvet-black, covered with thick golden pubescence, 

 in freshly emerged specimens entirely so. PlturcB brown, 

 lacking the patch of soft hairs. fFw/^^^ hyaline, veins brown, 

 radius unforked. Abdomen velvet-black, first segment with 

 a fringe of dark purple-ljrown hairs; a diagonal perlaceous 

 stripe on each side of the abdomen across the fifth, sixth, and 

 seventh segments, rather more iridescent blue in some lights. 

 Leys : front legs, coxse dark brown ; femora, apical ends 

 dark purple-brown, remainder covered with shining light 

 yellow hairs; tibiie, apical third dark purple brown, re- 

 mainder covered with light yellow hairs; tarsi almost black. 

 Hind legs : coxae dark purple-brown ; femora dark purple- 

 brown ; tibiae, basal third covered with light shining yellow 

 hair ; tarsi purple-black, second tarsal joint with excision 

 near base. Genitalia: basal pieces large; cias[)ers about 

 one-third the length of basal jjiece, having one finger-like 

 })rocess at the apex ; anal plates, the lateral i)latesvery long, 

 exceeding the length of the claspers, with a few short bristles 

 at the apex, the centre ])late large ; adminiculum rather 

 broad, with a fringe of short hairs and some very irregular 

 short spines at the apex of the trough ; arms, the arms end 

 mesally with a pair of spines, the outer one very long, the 

 inner verv short. 



