PUPAL STAGES OF WEST AFRICAN CULICIDJi:. 41 



Plumes on abdomen o£ moderate size, hairs plumose ; on segments .3-7 are 

 single long hairs, which are almost subplumose. Combs difficult to make 

 out, but appearing as three rows of equal short oblong scales, about 30 in 

 riumber, o£ which the anterior are the closest together (PL III, figs. 18 & 19). 

 The plumes at the base ot* the siphon are very closelj' plumose, and an 

 unusual feature is that the anal plume is also plumose, but in a much less 

 degree. 



The siphon is stout and tapers ; it is less than one-half the length of the 

 abdomen and is four times as long as its own base, being slightly swollen 

 above the latter ; there are no spines at the base, a space is bare for about 

 ^ of the length, then four short spines which run to about ^ ; then there 

 are some long subplumose hairs ; at the distal end of the middle third is 

 a short triple hair ; and on the lateral surfaces, nearly in the middle, are 

 single long hairs ; valves small (PI. Ill, fig. 17). 



The anal segment is narrow at the base, and carries stout blunt papillae, 

 the dorsal being about double the length of the ventral, which are nearly the 

 same length as the segment ; there are four long simple hairs on the dorsal 

 edge ; the beard is short and inserted at the end. There are single lateral 

 hairs in the middle of the posterior edge of the segment which are slightly 

 plumose, like the hairs on the abdomen ; the others are, as usual, simple. 



Length of larva 5 mm., siphon li mm. 



Pupa. 



The pupa is rather light in colour ; the trumpets are moderately short, and 

 have a slight cloud at their ends, being darker at the base ; there are some 

 single long hairs on the segments of the abdomen which are subplumose — an 

 usual condition in the pupse (PI. IV, fig. 1). 



Length of thorax 2 mm. 



Described from four larviX3 and four pupae. 



[Larvae found in July in a barrel standing in a water-hole. The barrel 

 was used by the natives as a washtub and contained very foul, opaque, 

 stinking water covered with froth. — W. M. G.] 



20. Culex albovirgatus, Graham. 



Larva. 

 Head rather narrow, nine units, as compared with thirteen units of thorax. 

 Antennae long ; at tAvo -thirds from base is a fan-shaped plume of plumose 

 hairs ; at the end, two short spines and three branched hairs ; a marked 

 constriction at the plume ; the lower part is covered with dark short sharp 

 hairs, which also show on the outer edge (PL I, fig. 1). All the mouth- 

 parts very hairy. The face is furnished with the usual plumes, six in 



