37 



thorns, more especially those nearest to the apex, not being in line; these thorns at 

 greater distance from each other than the following; the thorns of the middle part 

 of the pecten with one single tooth. Anal segment much longer than wide, almost 

 ringed by a plate. The dorsal tuft with two long hairs; the ventral brush in the 

 barred area with about ten rays, carrying from five to seven hairs; before the 

 barred area two small free tufts; lateral tuft consisting of a single hair; anal gills 

 very long, acute, equal. 



Lateral tufts of labrum long, distinctly divided into two parts, but without 

 comb teeth; palatum covered with very long hairs. Mandibles quadrangular with 

 two strong spines and a shorter one before collar; a row of long cilia from a col- 

 lar. About ten long thorn-like bristles; before them a dagger-like thinner thorn; 

 a few long feathered cilia below; process below indistinctly furcate with strong 

 hair-tufts; a group of hair at base. Maxilla? elliptical, divided by a suture; at apex 

 a brush of long hairs; a seta near the apex beyond the brush; near the inner 

 margin between it and the suture a coating of long hairs and at the margin a series 

 of long stiff thorns; palpe rather small with three digits. Mentum high, triangular, 

 without any conspicuous median tooth and with fourteen to sixteen teeth on each side. 



Colour almost white or yellowish white, head black and sipho and plate of 

 anal segment yellow. Length 6*5 m. 



The description and figures of the larva agreed well with those of Meijere 

 (1911 p. 148), his description being one of the most accurate of the hitherto published 

 of European mosquito larva?. The larva has probably been observed by Galli Va- 

 lerio in Svitzerland (1907). He has not however given any description of it; he 

 only says: "Die Larven sehen denen von Cule.v pipiens zum Verwechseln ahnlich; 

 sie haben denselben langen charachteristischen Atmungsfortsatz und die gleiche 

 Haltung; die Analdriizen (i. e. anal gills) sind etwas langer und schlanker und viel 

 durchscheinender. Die Farbe der Larve ist ein helles Gelbbraun und lasst sich Ieicht 

 gegen den dunklen Grund erkennen; wahrend die starker pigmentierten Larven von 

 C. nemorosus und annulipes sich den Blicken vollkommen zu entziehen wissen". 

 Further it has been described by Schneider from Bonn. The rather short descrip- 

 tion agrees well with Meijeres and mine. In 1919 it has been briefly described 

 from Strassbourg (Eckstein 1919 p. 294). 



Biology. Aedes cinereus is a little mosquito, which Staeger has mentioned 

 as rare in Denmark. As far as I know, nobody has found it later in this country. 

 In the days from 23/v to '-/vi 1918 A. cinereus was found flying over different 

 small ponds in North Seeland; the ponds were all almost quite dry, only containing 

 a few litres of water; about 15/vi they were dried out. On l/vi 1918 I found the species 

 in enormous swarms over the vast meadows at Lyngby on the southern coast of 

 Arreso. The above-named ponds were dry until ,5 /x and were icecovered almost 

 the whole time from about l/i 1919 to 1/iv 1919. In the time from 15 \ to ' i the 

 ponds contained no A. cinereus larvae. Being interested in finding the larva I explored, 

 in 1919, the localities where the imagines were found in 1918. On the meadows at 



