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neighbourhood of Hillered have told me that in the time from ten to twelve they 

 were stung in their bedrooms when the vindows were open by mosquitoes of a 

 remarkably slender form and with very long legs; unquestionably we here have to 

 do with A. bifurcatus, so much the more, as I myself have been, subject to attacks of 

 this species in my bedroom. In early spring when the evenings are cold, I have 

 also found the cobwebs in stables carrying numerous A. bifurcatus; at that time 

 A. maculipennis has not arrived here or is very rare. As soon as the evenings have 

 got warmer, A. bifurcatus disappears from the stables and is now a particular out- 

 poor species. In my opinion it is one of those mosquitoes of ours which have the 

 greatest power of flight. On calm very warm days with an overcast sky and sultry 

 air it may happen that the mosquitoes are on the wing even in the middle of the 

 day. On such days I have often been lying on the borders of our largest lakes and 

 watched how A. bifurcatus steered from the lake perpendicularly on the shore line; 

 I got the impression that the mosquitoes came directly from the lake having pas- 

 sed this and, if so, flown about two or three kilom. 



Everywhere in North and Middle Seeland where I have studied the pheno- 

 menon I have had an opportunity to observe the attack of A. bifurcatus in the time 

 from nine to twelve evening; only rarely was I attacked by A. nigripes and never 

 by A. maculipennis. The species of the genus Ochlerotatus did not quite disappear, 

 especially 0. cantans was troublesome but A. bifurcatus did not arrive before eight 

 or nine o'clock, and in most localities it preponderated over the Ochlerotatus-species. 



I have observed the males at two different times of the year; in the last days 

 of April and in the latter part of August and first days of September. The males 

 congregate in small swarms, commonly not consisting of more than from twenty 

 to a hundred individuals. On calm evenings or on days with warm weather and 

 overshadowed sky in the outskirts of the forests we may often find these small 

 swarms in the small "bays" in the foliage; these swarms of Anophelines are easily 

 recognizable from those of the Culicines owing to the picture of the position of the 

 body during the flight. Of a flying Culicin male we only see the body and the an- 

 tennae which are spread out laterally; a flying Anophelin male presents itself as a 

 much longer line, because the male palpi are pressed to the proboscis, and pro- 

 boscis and palpi appear almost as thick as the thorax and abdomen; this impres- 

 sion is augmented because also the antennae are held nearer to the proboscis 

 during flight than is the case \vith the Culicines. In the swarms the mosquitoes all 

 fly almost at the same distance from the earth, flying horizontally out and in 

 without altering the vertical position in the s'warm: More than once I have seen 

 the females following straight lines, steer their way directly into the little swarm 

 which is then in a moment altered into a ball in which the single individuals -are 

 pressed against each other; a few moments a pair drops out of the swarm, and 

 falls down into the grass where the mating is accomplished. On a calm day I once 

 saw such a whole series of dancing A. bifurcatus swarms all almost at line, all 



