NOTES ON CULICIDAE. 221 



Ochlerotatus alboventralis, Theo. (fig. 7/). 



A good series of both sexes of this species have been received from Kabinda, 

 Katanga {Dr. J. Schweiz), and also a single male from Kitui, British East Africa 

 {T. J. Anderson). It rather closely resembles 0. abnormalis and is possibly a 

 geographical form of it ; it can be distinguished by the presence of numerous white 

 scales on the mesonotum. There are also some differences in the male genital claspers 

 which are probably of specific importance. 



Subgenus Aedes, Mg. 



A considerable number of Oriental species must be included with A. cinereus in 

 this subgenus, the majority of them being so extremely similar in appearance that it is 

 difficult to find any characters, apart from those of the genitalia, to separate them. 

 When however the genitalia are examined, their structure is so extraordinarily diverse 

 that it is very difficult even to homologise the different parts. Thus the nine species 

 ceylonicus, virilis, singularis, imcns, leicesteri, pseudomediofasciatiis, yerhuryi, varietas 

 Sindfragilis, whose genitaha are shown in fig. 8 a-i, apparently only differ externally 

 in the width and position of some of the wing scales and the shape of the pale abdominal 

 markings, while several appear to be absolutely indistinguishable apart from genital 

 characters. All these species have a reddish-tinged thorax ; two other species, 

 butleri and jjanayensis (genitalia, fig 8 j and k) differ chiefly in having a blackish 

 thorax. These eleven species, together with A. cinereus, are the only ones of which 

 I have seen males, but doubtless many others occur in the Oriental region. Theobald's 

 fseudodmrna is probably distinct from any of those figured here. 



Aedes cinereus, Mg. 



Aedes cinereus, Mg., Syst. Beschr. i, p. 13 (1818). 



Aedes fuscus, O.S., Bull. U.S. Geol. Surv. iii, p. 191 (1877). 



There is, I think, no doubt that the European and North American species of 

 Aedes are one and the same. So far as I have seen, there is very little variation 

 among British examples, except that the thorax of the male is very often quite black 

 instead of reddish. The abdomen in these specimens is always dark brown above, 

 with, a pale lateral longitudinal stripe, the edge of which forms a straight line. Some 

 of the Canadian specimens in the British Museum are coloured in exactly the same 

 way ; others however have pale basal bands on the abdominal segments, and in these 

 the upper margin of the lateral pale stripe is indented towards the apex of each seg- 

 ment. Both these forms have the male genitalia absolutely identical in structure 

 with those of British examples, and it therefore seems justifiable to conclude that we 

 are dealing with only one species, which is more variable in North America than it 

 is in Europe.. 



Aedes ceylonicus, sp. nov. (fig. 8 a). 



Genitalia : Ninth tergite with a pair of terminal projections as in A. singularis, 

 but the clasper is minute. External characters as in ^. varietas, Leic. 



One male from Colombo, Ceylon (/{. McGahey). 



