NOTES ON THE BRITISH MOSQUITOS. 193 



Last joint of palpi never thicker than penultimate. 



usually distinctly thinner . . . . • 5. 



5. The smaller claw on the fore and luid feet simple 



(metatarsi with pale rings in the middle) 4. TiENiOEHYNCHUS. 

 The smaller claw on the fore and mid feet toothed 



(metatarsi not pale-ringed in the middle) 2. Ochlebotatus. 



Females : 



1. Palpi as long as proboscis .... 1. Anopheles. 

 Palpi much shorter than proboscis . _ . . 2. 



2. Claws toothed (rarely the hind pairs are simple); 



abdomen pointed ; ovipositor externally promi- 

 nent ......... 3. 



Claws all simple ; abdomen usually blunt-ended ; . 

 ovipositor hardly visible externally . . . 4:. 



3. Head almost covered with broad flat scales . . 3. Aedes. 

 Middle of head (above) with only quite narrow 



scales 2. Ochlerotatus. 



4. Hind metatarsus shorter than the tibia . . 5. 

 Hind metatarsus as long as the tibia . . .6. Culex. 



5. Cross-veins separated by less than the length of 



the posterior ; lateral vein-scales narrow . 5. Theobaldia. 

 Cross-veins separated by more than the length of 

 the posterior ; lateral vein-scales mostly rather 

 broad 4. T^nioehynchus. 



Genus 1. Anopheles. 



The species of this genus are readily recognized by the long 

 female palpi, and by a number of minor characters, such as the 

 absence of scales on the body. 



We have only three species o( Anopheles in Britain. Theobald, 

 indeed, states that he has taken a fourth — the North American 

 A. barheri — in England, but this requires confirmation. The 

 larva of A. barheriis distinguished from those of other Anopheles 

 by "the slight development of the head hairs, the presence of 

 plumose hairs after the third abdominal segment, and the 

 absence of short teeth on the comb of the eighth segment." 



1. A. macuUpennis, Mg. ; the Spotted Gnat. — Distinguished 

 from the other two species by the presence of spots on the wings, 

 formed by the accumulation of scales. Grey-brown to grey- 

 ochreous in colour. Average length (without proboscis), 6 mm. 



Widely distributed in the south and east of England, and 

 common in marshy places ; occurs also in North Wales. 



2. A. bifnrcatus, h. — Closely resembles A. macuUpennis in 

 size and colour, but differs most obviously in the entire absence 

 of the dark spots on the wingSc It seems to be less common 

 than the preceding, but has a similar distribution. 



3. A. plumbeus, Stephens. — Smaller and darker than the 

 two preceding ; the wings are somewhat narrower, the scales 



