18 
A Monograph of Culicidae. 
the mid cross-vein, not quite its own length distant from it. 
Halteres with yellow stem and brown knob, covered with 
greyish white scales. 
Length .—5 to 5*5 mm. 
£. Palpi deep brown, with paler bands at the bases of the 
joints, a hair tuft at the base and another at the apex of the 
penultimate joint. 
Length .—5 mm. 
Habitat .—Scandinavia (Zetterstedt); Holland (Van der 
Wulp); Berlin (Meigen); Austria (Schiner); England (Walker, 
Piffard, Bradley, F. V. T., &c.). 
Time of appearance. —In England in August (Piffard, F. V. T.); 
in Southern Scandinavia in June and September (Zetterstedt); 
in Denmark in August (Staeger); in Holland in August (Van 
der Wulp). 
Observations .—This gnat in many respects resembles 0. pulcri- 
tarsis of Rondani, but differs from it in not having the last hind 
tarsal joint white, 4nr-the -«imple ungues and in the—venation, 
but at first sight it bears a strong resemblance, especially in 
regard to the marked thoracic ornamentation. This mosquito 
seems widely distributed in Europe, and in some places is locally 
very abundant. Mr. Piffard * records it in “ vast numbers ” at 
Aldeburgh on the Suffolk coast, where it is known as the “ Norway 
mosquito.” It seems to have been abundant there for at least 
the last twenty-five years. “ A tradition,” says Mr. Piffard, 
“ accepted here (Aldeburgh) assigns its introduction to a 
particular yacht which used to ply between this port and 
Norway.” I have found it in numbers in a garden at Rochester, 
where it caused much annoyance, and Mr. Bradley also sends 
me a specimen from Wyre Forest. It appears to be not rare at 
Copenhagen, for Staeger found the adult not uncommon, whilst 
the larvae were in great abundance in lagoons in the Island of 
Amagu at Copenhagen. In Norway it is evidently rare, for I 
can only find one record, namely from Christiania. The bite is 
very severe and the insect most ravenous in warm weather, biting 
both night and day. I have noticed that this species prefers 
settling on a.dark surface, people with black clothes for instance, 
being especially chosen for their attack. 
* Ento. Mo. Mag. p. 227 (1895). 
