194 THE ENTOMOLOGIST. 



being blacker and rather denser ; the thorax (in good specimens) 

 is ashy-grey in the middle, blackish at the sides, and bears 

 anteriorly some white hair-like scales, the vestiture of the 

 thorax in the other two species being yellowish ; the abdomen 

 is black, not brown or greyish-brown. Average length, 4-5 mm. 

 This species seems to have a wider distribution than the 

 other two, as it has been recorded from Scotland and Ireland. 

 As Theobald remarks: "There is little doubt that Haliday's 

 [Stephens's] A. plumheus, taken in the North of Ireland in 

 July, is this species [A. nigripes, Staeger]." It is best known 

 under this latter name. 



Genus 2. Ochlerotatus. 



This genus includes most of the European species till recently 

 placed in Ciilex. It is, however, at least as distinct from Culex 

 as Acdes is. The eggs are deposited singly (as in Acdes), not in 

 masses (as in Culex). 



The writer has been able to recognize eight species in Britain, 

 which can be distinguished as follows : — 



1. Tarsi (especially those of the hind legs) pale-ringed . 2. 

 Tarsi entirely dark . . . " . . . . 5. 



2. Pale rings of tarsi embracing both ends of the joints, 



on hind legs the whole of the last joint is pale . 1. dorsalis. 

 Pale rings of tarsi at bases of joints only ... 3. 



3. Pale rings of hind tarsi very narrow ; wing-scales all 



dark 2. vcxans. 



Pale rings of hind tarsi broad, except on first and last 

 joints ; wings with both dark and light scales . 4. 



4. Yellower species ; a broad band of yellowish scales 



on each side of the mesonotum . . . .3. ammlipes. 

 Browner species ; mesonotum mostly brown-scaled, 

 with lateral spots or lines of whitish scales . 4. maculatus. 



5. Segments of abdomen with basal pale bands ; mar- 



gins of thorax not whitish 6. 



Segments of abdomen with lateral basal white spots ; 

 margins of mesonotum broadly wdiite-scaled . . 8. lateralis. 



6. Wings speckled with light and dark scales, on nearly 



all the veins 5. salinus. 



"Wings with few or no light scales . . : . 7. 



7. Pale bands of abdomen yellow, tending to spread out 



in the middle, and sometimes forming a median 

 yellow line on the last few segments . . .6. divcrsus. 

 Pale bands of abdomen whitish, tending to spread 

 out laterally, and sometimes almost divided into 

 pairs of triangular spots .... 7. nemorosus. 



1. O. dorsalis, Mg. — Scales of head bright reddish-brown at 

 the sides, whitish in the middle. Thorax mainly clothed with 

 bright reddish-brown scales, but with two rather broad whitish 

 longitudinal stripes. Wings and legs speckled with dark and 



