328 F. W. EDWARDS. 



Lamhorn). North India (Punjab, Barroia ; female only). Probably widely distri- 

 buted in the Oriental region, but confused with the two species above mentioned 

 and with the Ethiopian L. tigripes. 



Genus Culex, L. 



This genus, I find, is sharply distinguished from almost all other mosquitos by 

 the possession of distinct pulvilli. It is remarkable that the presence of these structures 

 has been overlooked for so long ; Howard, Dyar and Knab even state positively 

 that they are absent throughout the family ; these and other writers must either 

 have omitted to study Citlex closely, or else have used an insufficient magnification. 

 I have examined a large number of species of this genus, and find pulvilli present 

 in all ; they do not vary much in size, but are naturally more easily detected in the 

 larger species. Figs. 5 d and 5 e (made with the aid of a camera lucida) show clearly 

 the different appearance under a sufficiently high power between a hairy empodium 

 and a pair of true pulvilli. In the front and middle tarsi of the male the pulvilli, 

 like the claws, are elongated, and therefore less noticeable ; they may be seen, 

 however, on the hind tarsi as well as on all the feet of the female. The only other 

 mosquitos which possess pulvilli are the genera which on other grounds have already 

 been regarded as close allies of Ctdex : Culiciomyia, Lophoceratomyia, Micraedes 

 Canollia, Lutzia, and Deinocerites (including Dinomimetes). The first three or four 

 of these should not be regarded as more than subgenera of Culex, though the last 

 two may be treated as distinct genera. 



The following characters are also common to most if not all species of Ctdex ; 

 some of these will further help to distinguish the members of this genus from Aedes : 

 Eyes very narrowly separated or even touching for a considerable length above the 

 antennae. Proboscis not or scarcely longer than the front femora. Male palpi 

 when long always slender, with the last two joints upturned. Male antennae always 

 plumose, with the hairs spreading out evenly all round. Spiracular and post-spiracular 

 bristles absent. Usually only one lower mesepimeral bristle or none ; very rarely 

 two or three. Female abdomen blunt-ended, the cerci short and broad, eighth 

 segment not at all retractile. Male hypopygium without claspettes or basal lobes 

 to the side-pieces, but with subapical lobes bearing modified bristles. Tenth sternifes 

 ending in a tuft or comb of spines. Mesosome a paired structure with pointed pro- 

 cesses. Claspers articulating in a more or less vertical plane. First joint of hind 

 tarsus as long as the tibia or slightly longer. Female claws always simple. Wings 

 with distinct microtrichia on the membrane ; cell R^ markedly longer than its stalk 

 in the female ; vein A„ ending much beyond the level of the base of R^. 



Larva. — Antennae with a distinct hair-tuft, which is generally well beyond the 

 middle, the part of the antenna beyond the tuft usually rather suddenly narrowed, 

 and with few or no spinules ; two long preapical spines. Hairs of mouth-brush 

 simple. Frontal hairs rarely if ever single, and never placed one in front of the other. 

 Anal segment with a complete chitinous ring (in the fourth stage only). Siphon 

 with numerous ventral tufts, or else greatly elongate. 



The genus is essentially tropical and sub-tropical, only a very few species 

 extending into the temperate regions. Only C. apicalis and the domestic 

 C. pipiens and C. fatigans are common to Europe and North America. 



Three fairly well-marked subgenera occur within the Palaearctic region, as 

 indicated in the following keys. 



Adults. 



1. First joint of hind tarsi distinctly shorter than the tibiae ; small 



obscurely coloured species {Barraudius) . . . . . . . . . . 2 



First joint of hind tarsi scarcely, if at all, shorter than the tibiae . . 3 



