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Sayomyia and a typical Culicid larva. The intermediate condition is 
especially well indicated in the tracheal system which, although it has 
undergone some amount of reduction, is much better developed than in 
Sayomyia and, moreover, spiracles are present. They are situated at 
the extremity of a short respiratory siphon arising from the eighth 
abdominal segment. Gorethra resembles Sayomyia in the form of the 
antennae but the head is not prolonged anteriorly (Meinert, Tab. II). 
The larva of G. Karnerensis is remarkable in having the extremity of 
the last segment bordered by a whorl of numerous, short, recurved 
fleshy processes (Felt, 1904, p. 353). 
The larvae of both Eucorethra and Corethrella resemble Gorethra 
much more closely than Sayomyia. Both possess a well developed 
tracheal system resembling that of Culex and opening at the extremity 
of a short siphon. The antennae in Eucorethra resemble those of the 
two preceding genera while those of Corethrella are curiously folded 
back against the head (Felt). 
Pelorempis is a recently discovered form and very imperfectly 
known. It resembles Sayomyia and Gorethra in the elongated antennae 
which are provided with stout spines set at an angle with their long 
axes. It has the general shape of the head of Gorethra but the 
maxillae rather resemble those of Sayomyia. In its respiratory system 
it comes closer to the Anophelinae than to any other of the Culicidae. 
There is no siphon and the spiracles are supported by a chitinous 
skeleton resembling very closely that of Anopheles (Johannsen, p. 404). 
Pelorempis seems, therefore, to be a synthetic type as regards its 
larval characters, since it exhibits features belonging to both Corethrinae 
and Anophelinae. 
The relationships of the larvae of the Corethrinae appear on the 
whole to come nearest to the Culicinae. The fact that they are 
predaceous, feeding on larvae of their own and other species, and small 
Entomostraca, &c., might suggest the possibility of their having arisen 
from the Megarhininae ( sensa latiore of Christophers) which are 
similarly carnivorous (and cannabalistic). Such a view, however, 
would not be tenable since, in the Corethrinae, the antennae are the 
organs which are specially modified for seizing the prey, while in the 
latter group, it is the feeding brushes that have become modified for the 
same purpose. 
Rondani in 1856 appears to have been the earliest writer to 
separate the Corethrinae from the rest of the Culicidae and elevate 
them to family rank. More recently Coquillett and others have also 
