—— 
culiciformis, De Geer. 375 
De Geer seems only to have known the male, as he only 
describes and figures that sex; but unfortunately the descrip- 
tion is very incomplete, and the figures are not much better. 
Nevertheless upon this description and these figures a distinct 
genus, Corethra, was afterwards established, and for this 
genus De Geer’s species was thus the type. Subsequently 
other small flies were also either transferred to the genus 
Corethra (such as Tipula plumicornis, Fab., which, under the 
name of “ Corethra plumicornis,” is one of the best-known 
and most frequently examined insects) or established as new 
species of Corethra (such as C. pallida); but until now no 
one seems to have found De Geer’s gnat, unless the Corethra 
velutina, described by Ruthe in the ‘ Isis’ for 1831, should 
be identical with De Geer’s Tipula culiciformis*, which, how- 
ever, is not probable. ; 
De Geer’s diagnosis of the imago runs as follows :— 
“Tipule brune, 4 antennes filiformes en plumes dans le male, 
4 ventre et pattes grises, et dont les nervures des ailes sont 
velues.” “ Tipula (culictformis) fusca, antennis filiformibus 
maris plumosis, abdomine pedibusque griscis, costis alarum 
hirtis.” In conclusion he gives (/.c. p. 378) a fuller descrip- 
tion of the imago; but in this he adds nothing to what he 
gives in the diagnosis or what can be seen in the figures 
(figs. 11 and 12), except that the antenne are stated to be 
black. 
In the “ Versuch einer neuen Gattungs-Eintheilung der 
europiischen zweifliigeligen Insekten, von Joh. Wilh. Meigen,” 
which Illiger published in his ‘ Magazin fiir Insektenkunde ’ 
(Bd. 11. pp. 259-281, 1803), Meigen established the genus 
Corethra, and cited as the single or typical species of that 
genus Tipula culiciformis, De Geer (/. c. p. 260). Also in 
* For synonymic purposes Walker's Mochlony.x effetus (‘Insecta Britan- 
nica,’ Diptera, ii. p. 252) and Gimmerthal’s Corethra pilipes (Bull. 
Moscou, ii. p. 287), as well as Van der Wulp’s Corethra obscuripes 
(Tijdschr. Entom. Nederl. Vereen, ii. p. 160), should be examined ; but 
this was impossible for me, and I doubt whether others will gain much 
advantage by it. 
[It is to be remarked that Walker, or rather Haliday, the real authority 
for this part of the ‘ Insecta Britannica,’ not only describes Mochlonyx 
effetus, as above cited, but also cites De Geer’s Tipua culiciformis as a 
species of Corethra. He describes both sexes of the latter, and notices 
the species as “not generally common, but sometimes appearing in great 
profusion.’ He describes the antennee in Corethra as fourteen-jointed, 
and those of Mochionyx as sixteen-jointed; but the figure of the male 
antenna of M. velutinus shows only fifteen joints. On the other hand, 
Meinert’s figures which accompany the present paper in the Danish 
original show the male antennie of fifteen, and those of the female of 
fourteen joints, although from his description the number would appear 
to be the same in both sexes.—W. 38. D.] 
