MOSQUITOS OF THE PALAEARCTIC REGION. 315 



(?) Culex sylvaticus, Meigen, Syst. Beschr. i, p. 6 (1818). 



Aedes obscurus, Meigen, Abbild. Zweifl. Ins, pi. ii, fig. 2 (1830). 



Culex lazarensis, Felt & Young, Science, xx, p. 312 (1904). 



Culicada nemorosa forma diplolineala, Schneider Verh. Nat. Ver. Bonn, Ixx, 



p. 37 (1913). 

 (?) Aedes tahoensis, Dyar, Insecutor Inscitiae, iv, p. 82 (1916). ■ 

 (?) Aedes pionips, Dyar, Insecutor Inscitiae, vii, p. 19 (1919). 

 Ochlerotatiis palmeni, Edwards, Ent. Tidskr. p. 52 (1921). 



This is one of a group of species which can only be satisfactorily chstinguished 

 b}' the structure of the male hypopygium. When this organ is mounted and 

 examined under the high power of a binocular microscope, A. communis may be 

 readily distinguished from other species by the two ridges at the base of the appendage 

 of the claspette. These are best seen when the whole hypopygium is viewed from 

 above ; the small additional ridge is on the outer side of the appendage and at the 

 base only. The long, strongly arched stem of the claspette and the form of the basal 

 lobes seem to show that A . communis is more closely related to A . cataphylla and 

 A. salinellus than to A. pullatus or A. pnnctor, though in coloration the first two 

 species are more easily distinguished from A. communis on account of their speckled 

 femora and tibiae. The indications of relationship afforded by the male 

 hypopygium are also supported by the larval characters. 



A. communis is evidently one of the most abundant woodland mosquitos of Europe, 

 and is no doubt the species which has most frequently been identified as Meigen 's 

 C. nemorosiis. This, together with the fact that a male of the species is included 

 in Meigen's series of C. nemorosits in the Paris Museum, will definitely settle this 

 name ; although Meigen's description (brownish-yellow thorax, etc.) does not agree. 

 De Geer's description of the adult and larva of C. communis, however, is quite suffi- 

 ciently detailed for identification, and I have therefore adopted his name for the 

 species. The disappearance of the name ncmorosus from dipterological literature 

 will be an advantage rather than otherwise, since it is now known that a number of 

 species have been confused under this name. 



I have examined the type of Meigen's Aedes obscurus, which I received on loan 

 through the kindness of M. Seguy. The hypopygium is apparently identical with 

 that of A. communis, and the short palpi (if they were not merely broken) were 

 therefore probably an individual abnormality similar to those which I have recorded 

 as occurring in A. pnnctor. 



In describing C. nemorosits, Meigen refers to his earlier description of C. reptans 

 (Klass. i, p. 3, a doubtful identification of Linnaeus' C. reptans) as synonymous. 

 In this earlier description, however, the tarsi are said to be white-ringed, so that the 

 same species cannot have been referred to in both descriptions. The explanation 

 probably is that Meigen intended to give a reference to his C. lencomelas, very briefly 

 diagnosed immediately after C. reptans, with the remark, " Diese Art, die vielleicht 

 nur eine Abandrung der vorigen ist, unterscheidet sich von derselben bloss durch 

 die ganz schwarzen Fiisse." This name C. leucomelas has been overlooked, and 

 will unfortunately necessitate the renaming of a South American species. 



Meigen's C. sylvaticus {fasciatus, 1804) is impossible to determine from the 

 description, and I see no particular justification for Martini's suggestion that it is 

 Cidex apicalis ; since the type does not exist it will be as well to accept Meigen's 

 statement (Syst. Beschr. vi, p. 241) that it is only his C. nemorosus. 



The American forms A. lazarensis and A. tahoensis, and probably also A. pionips, 

 differ in such minute details that they can hardly be ranked as more than varieties 

 of A. communis, but it is interesting to note that the hypopygium of the Alaskan 

 tahoensis is the more nearly identical with European communis in regard to the exact 

 position of the spine on the basal lobe of the side-piece, the only point in which Dyar 

 has indicated distinctions between the American fomis. I had intended to describe 



