PUPAL STAGES OF WEST AFRICAN CULICID.^. 39.. ■ 



plumes of six simple hairs show on the posterior portion of most of the other 

 segments, on the dorsum. At about the same focus, minute stellate hairs or 

 plumes may be seen, and right on the back are a few long subplumose single 

 hairs. The comb is very difficult to see, but bj arranging the larA'a so as to 

 obtain a horizontal view along the back (the head balances on the long- 

 antennae) three unusually long strong dark spines are visible on the edge of 

 the segment. Siphonal plumes moderate in size, sub-siphonal large, and 

 both of plumose hairs. 



The siphon is short, four times as long as the base, about one-third of the 

 length of the abdomen ; a dark ring encircles it in one specimen which is 

 absent in the other (PL VII, fig. 7). The spines are weak and run for 

 about one-third of the length ; on the median line is a single hair, and it is 

 followed at equal distances by four plumes of about six plumose hairs ; in 

 the upper third are lateral triple hairs ; the valves are very large, particularly 

 the ventral. 



The anal segment is small, as are also the papillae, which swell from a 

 narrow base and diminish to pointed ends ; they are longer than the segment, 

 and the ventral pair is longer than the dorsal, which is unusual ; in one 

 specimen the ventral ones are slightly chitinised. On the dorsal edge is a 

 curious hair, which is strong at its base and has others springing from it. 

 The ventral beard is longer than the papilla.^ and runs for about a third of 

 the segment. 



Larva 4|- mm. long, siphon over 1 mm. 



Pupa. 



Very dark, with long and thin trumpets, which have a lighter ring in the 

 middle ; there are plumes on both the sixth and seventh segments, both of 

 branched hairs, and the anal plates have a distinct dark cloud in the middle 

 (PI. VIII, figs. 5 & 6). 



Length of thorax 1^ mm. 



Described from two larvae and three pupae. 



[Larvae found in borrow-pits in June and July. — W. M. G.] 



18. Culex nigrocostalis, Theo. 



Larva. 

 Head not quite so broad as thorax, light in colour. Antennae fairly longv 

 also light in colour, with a small, darkened, chitinous ring at the base; plume 

 large, with plumose hairs; the distal joint is a shade darker than the proximal 

 one ; it carries three long simple hairs and a spine at the end. Face with short 

 plumes, brush rather stiffly haired, p-oment spots large at base of antennae. 



