136 A. INGRAM AND J. W. S. MACFIE. 



The thoracic plumes are fairly developed, the median hairs overlap the occiput- 

 There are no rudimentary palmate hairs on the thorax or the first two abdominal 

 segments. 



There are long lateral feathered hairs on the first three abdominal segments and all 

 the segments bear short branched hairs laterally. Palmate hairs are present on the 

 fourth to the seventh abdominal segments. The leaflets of which these hairs are 

 composed show no shoulder and scarcely any filament. Upon an average there are 

 nine hairs on each side of the main stem (in A. costalis the average number is seven) 

 when the structure is looked at in profile. The comb differs from the comb of 

 A. costalis in that the long teeth are, relatively to the short teeth, more elongate and 

 more numerous. Wesche, describing the comb of A. costalis (Bull. Ent. Kes., i, p. 21) 

 in the various stages of development of the larva, says of the final stage, " the character 

 of the comb remains the same, four short spines followed by a long one." In the 

 comb of A. marshalli there appear to be three short spines followed by a long one. 



This larva falls into the same group as A. pretoriensis and A. rufipes in Edwards' 

 key (Bull. Ent. Kes., iii, p. 374), but is distinguished from them by having no palmate 

 hairs on the second abdominal segment. 



Breeding place. — This larva was taken in a Pistia-covexed pool at Christiansborg, 

 near Accra (see PL II, fig. 1). From the same pool larvae of A. costalis, Aedeomyia 

 africana, Culex quasigelidus, Mimomgia splendens and Mansonioides africantes were 

 obtained. 



Stegomyia simpsoni, Theo. 



The head is small and moderately chitinised. The antemia is short and bears in 

 place of the tuft a single hair at about its middle or a little beyond. There are several 

 small tufts of hairs and one tuft of three long hairs arising between the base of the 

 antenna and the eye and projecting laterally. The mental plate has a median pointed 

 tooth of moderate size and ten or eleven smaller teeth on each side, the two outermost 

 teeth being much smaller than the others. The brushes are small. 



The thoracic plumes are not very strongly developed and are composed of simple 

 hairs. The hook-like spines at the bases of the ventral plumes are about as strongly 

 developed as those of S. fasciata. 



The abdomen is not conspicuously hairy and is without true stellate hairs. All the 

 hairs are simple. The hairs forming the siphonal, subsiphonal, and anal plumes 

 appear also to be simple. The comb consists of a row of seven or eight spines barbed 

 at their bases, which resemble those of S. fasciata but are rather less strongly barbed. 

 The siphon is less than twice as long as its basal diameter. The pecten is composed 

 of about eight slightly barbed spines. The tuft is situated just beyond the middle 

 of the siphon and is composed of three simple hairs ; it lies at about the same level 

 as the last pecten spine. The beard is poorly developed. The dorsal hairs on the 

 anal segment are three above and one below on each side. The anal papillae are long 

 and blunt at the ends. 



The above description was made from a single specimen, but unless it was an 

 abnormal one, this larva can be distinguished from the other known larvae of this 

 genus with barbed comb spines and without conspicuously hairy abdomens by its 

 pecten of only eight spines. 



