NOTES ON THE BRITISH MOSQUITOS. 263 



Genus 6. Culex. 



1. C. pipiens, L. ; the Common Gnat. — Thorax brick-red to 

 dark reddish-brown. Abdomen dark brown, the segments with 

 basal yellowish bands. Legs dark brown, the femora pale 

 beneath. First fork-cell very long, quite four times as long as 

 its stem. Average length, 5 mm. 



Common everywhere. 



A small dark variety (?) of this species has been described by 

 Theobald as CiUex nigritulm, Zett. It is certainly not G. nicjritulus, 

 which is a synonym of A'edes cinereus, Mg. At first sight this variety 

 appears to be totally distinct from C. pipiens, as it is much smaller 

 (only 3-3-5 mm. in length) and darker, the thorax being without any 

 reddish tint. No external structural differences, however, are ob- 

 servable, and after carefully comparing the larvae of this and typical 

 C. pipieiis I could find no differences whatever. However, it seems 

 worthy of a name, varietal if not specific, and I propose to call it 

 C. pipiens var. doliorwn (nov.). I found it swarming in water-barrels 

 at Kingswear, South Devon, last autumn ; all the adults were of uni- 

 form small size and dark grey-brown colour. The male genitalia 

 differ from those of typical G. pipiens in having the basal process of 

 the harpes quite well developed ; I cannot detect the small third 

 plate of the harpagones described by Dyar and Knab as characteristic 

 of C. pipiens. 



Keputed British Species. 



Stephens records the following as British, but no recent 

 examples have been found : — Cidex calopus, Mg. ; C. ornatus, 

 Mg. ; C. domesticm, Germar ; G. bicolor, Mg. ; C. punctatus, 

 Mg. ; C. lutesceiis, F.; C. rufiis, Mg. With the exception of the 

 first two, these have not been recognized by any recent author. 

 Theobald regards C. punctatus as synonymous with C. rusticus, 

 Eossi, and it was included in the last British List under this 

 name. 



Culex fumipennis, Stph., and C. marginalis, Stph., were origi- 

 nally described from Britain, but are probably unrecognisable 

 unless from types. 



Key to the known Larv^ of British Culicin^. 



1. Air-tube absent A. maculipcnnis. 



Air- tube present 2. 



2. Air-tube quite six times as long as its breadth in 



middle 3. 



Air-tube at most four times as long as its breadth 

 in middle ........ 5. 



3. Several scattered hair-tufts on air-tube . . Gulex pipiens. 

 Only one tuft of long hairs close to base . . 4. 



4. Five or six smooth spines on air-tube beyond 



pecten Th. theohaldi. 



No spines on air-tube beyond pecten . . . Th. morsitcms. 



