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A Monograph of Culicidae. 
9 
probably on Culex pipiens, L.; Anopheles by Meigen (Syst. Beschr. 
i. 10), 1818, also Aedes (i. 13) and Coretlira (Ill. Mag. ii. 260). 
In 1844 another genus was added by Low, namely, Mochlonyx 
(Stett. Ent. Zeit. 1844, 121). 
Robineau Desvoidy, in his “ Essai sur les Culicides ” (Mem. 
de la Soc. d’Hist. Nat. de Paris, iii., in 1827), instituted the 
genera Megarhinus, Psorophora, and Sabethes for certain exotic 
species which had previously been included in the genus Culex. 
Meigen’s and Linnaeus’ genera have always been accepted, as 
has also Robineau Desvoidy’s genus Megarhinus , but Wiedemann 
and others seem to have discarded Sahethes. Low (Dipt. 
N. America, pt. i., p. 5, 1862) did not accept, it seems, either 
Psorophora or Sabethes, for he says in the above work, after 
referring to Desvoidy’s genera, “ the last two ( Psorophora and 
Sabethes) being scarcely tenable.” Nor does Williston give them 
in his table of genera of the Culicidae of North America (Man. 
of Families and Genera of N. A. Diptera, p. 22, 1896). In spite 
of not having been generally accepted by older Dipterologists, 
Lynch Arribalzaga (Dip. Argentina, pp. 38 and 66) has revived 
both Psorophora and Sabethes, and in this I quite agree, but the 
generic definitions I find have to be somewhat altered—in the 
main, however, the genera hold good. The only other genera 
formed for this large family were instituted by Lynch Arribal¬ 
zaga in his excellent monograph of the Culicidae of the Argentine 
Republic, &c. In this he further divides off from the genus 
Culex four genera, Ochlerotatus , Taeniorhynchus , Janthinosoma , and 
Peteronycha. From the genus Aedes he separates some species 
under the generic name of Uranotaenia. Two of the four genera 
related to Culex I have been compelled to discard after trying 
hard to retain them, but in all cases the generic definitions failed 
when I examined other insects, undoubtedly closely related. The 
characters on which he founded these genera seem to be more 
specific than generic, and, if they were followed out, would 
occasion the formation of such a large number of genera from 
the old genus Culex that no single one would contain more than 
one or two species. The form of the £ palpi varies in nearly 
every species; in the .$ there is not so much variation, but as 
they are often hidden completely in scales the joints cannot be 
counted, so that unless we have a number of specimens to break 
up we cannot see the jointing, and thus the character made of 
generic importance could not be always used in identification, 
whilst the structure of the ungues is even more versatile than 
