26 
During winter and early spring, Common Gnats are often to be found 
in swarms on the roofs of cellars, where their presence at that season of 
the year sometimes occasions a good deal of surprise. This species 
is often a troublesome blood-sucker, and, as most people know to their 
cost, even a solitary Gnat is capable of causing considerable 
annoyance in a bedroom at night. As regards his experience of the 
Common Gnat in Scotland, Colonel Yerbury says : — " This is another 
early pest, which was in numbers at Nairn and Brodie in the middle 
of May, 1905 ; eight or ten specimens could be seen at one time 
sitting on one's knickerbocker stockings." 
Culex pipiens occurs throughout Continental Europe, and also in 
Malta, Algeria, Madeira, Teneriffe, and North America. 
Genus 
GRAB HAM I A, Theobald. 
Grabhamia dorsalis, Mg. 
{Culex dorsalis, Verrall, ' List of British Diptera,' 2nd Ed. 
(1901), p. 12.) 
Plate 9. 
This species, which is quite the most handsome of our British 
mosquitoes, may easily be recognised by its bright tawny thorax 
marked with two longitudinal stripes of cream-coloured scales which 
meet behind, and by the striking pattern of the abdominal markings, 
which are clearly shown in the plate. G. dorsalis makes its appear- 
ance in August and September, when it is often locally abundant in 
some of the suburbs of London. At present it is impossible to say 
anything as to the distribution of this species in the British islands, 
since all the British localities whence it has hitherto been recorded 
are in England, for the most part in the southern counties. 
Theobald, however {pp. at., Vol. II. (1901), p. 18), mentions its 
occurrence in Wyre Forest, Worcestershire (where it was taken by 
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