culiciformis, De Geer. 377 
form of a Culex larva, may be different.” As we see here, 
it is the larval form of C. culiciformis, and the great difference 
that exists between this larva and the larva of another species 
of the same genus, C. plumicornis, Fab., long previously de- 
scribed and figured by Réaumur, Goeze, Slabber, Lehmann, 
Goring, and Lyonnet, that called forth in Steger this exceed- 
ingly justifiable doubt as to the correctness of the synonym. 
Besides the doubt came the more home to Steger, or was the 
more justified in him, as he had reared his new species, 
Corethra fusca, from a larva which certainly differed in two 
essential structural characters from the larva of C. plumi- 
cornis, but the differences of which are confined within pro- 
bable limits. But that the differences were far from being so 
great as Steger believed, and especially that the larva comes 
much nearer to the larve of Corethra than to those of Culex, 
nay, that the newly discovered larva of Corethra fusca in its 
most essential differences from the larva of Corethra plumv- 
cornis, namely the cleft sete in the tail- and swimming-fins, 
agrees with De Geer’s larva, Steger could not well see—in 
any case he did not take it into consideration; and he had 
not, any more than any one else since De Geer, himself seen 
the larva of “* Tipula culiciformis.” It was the external re- 
semblance in habit to Culew-larve which had already struck 
De Geer, and perhaps also especially the posterior breathing- 
tube that had raised doubts in Steger. The same doubts, 
moreover, were expressed soon after by Westwood in his 
‘Introduction’ (2. c. p. 515), who says, “I fear there must 
have been some errors either in De Geer’s observation or in 
Latreille’s synonym, inasmuch as Réaumur’s figures of the 
transformations of a species described as Corethra plumicornis 
totally differ from De Geer’s.” 
Zetterstedt, in the ‘ Diptera Scandinavie’ (tom. ix. 1850, 
pp. 3474 et seq.), exactly follows Steger, and also cites 
Meigen’s and Macquart’s C. culictformis with doubt under 
Steger’s C. fusca. Upon this he says, in note 1, “ Tipula 
culiciformis, De Geer, ob larvam tamquam larve Culicis 
similem ibidem descriptam, nec ‘ flavicantem, hyalinam, pel- 
lucidam * (qualis larva C. fusce deprehensa), a D. Steger ut 
a C. fusca diversa species habetur.”’ 
From a faunistic point of view it is very remarkable that 
neither Steger, who was an industrious collector of Diptera, 
especially in the neighbourhood of Copenhagen, nor Zetter- 
stedt, who, besides his own and all the Swedish collections, also 
received from collectors in this country, and especially from 
Steger, all their Diptera for examination, should have met 
with Tipulu culiciformis, or its exceedingly peculiar and easily 
Ann. & Mag. N. Hist. Ser. 5. Vol. xii. 28 
