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Anopheles Macidipennis 
General Remarks on the Larvae of the Gulicidae. 
The larvae of the Culicidae may be defined as being aquatic, 
eucephalous, and with the first three post-cephalic segments fused 
together to form an evident and greatly enlarged thoracic mass. 
Although there is but little difficulty jn identifying typical Culicid 
larvae, the greatly enlarged thorax affords the most evident constant 
morphological character, which is common to all the larvae of the 
family, and by means of which they may be readily separated from 
those of the allied Nemocerous families Dixidae, Psychodidae, Tipulidae 
and Chironomidae. It is true that, in the latter family, the first three 
post-cephalic segments become greatly swollen towards the end of 
larval life, in consequence of the developing imaginal organs contained 
within them. In the larval Chironomidae, however, there is no fusion 
into a compact thorax though the limits between the second and third 
segments may become partially obliterated. That the thorax of the 
Culicid larvae is composed of the first three post-cephalic segments is 
evident from the fact that it contains three of the ventral nerve ganglia, 
together with three double series of buds of the imaginal thoracic 
appendages, and moreover its musculature retains to some extent 
a trisegmental arrangement; externally, however, its composition is 
not by any means obvious. In Gorethrella brakeleyi Coq. according 
to Johannsen (p. 401, pi. 40), the three segments can be perfectly 
clearly made out, since they have not undergone the same degree of 
fusion seen among other Culicid larvae. As a rule, the only external 
indication is to be seen in the principal hairs being arranged in three 
main transverse series. In all Culicid larvae the abdomen consists of 
nine segments. 
Three principal types of modification are to be seen among Culicid 
larvae, viz. 
(1) The Anopheles type where the tracheal system communicates 
with the exterior by means of a pair of spiracles situated on the dorsal 
aspect of the eighth abdominal segment, and the respiratory siphon is 
not developed. Palmate hairs are present on a variable number of the 
abdominal segments 1 , and the comb scales are replaced on either side by 
a chitinous plate bearing a series of posterior teeth. 
1 In some species (A. fluviatilis and A. culicifacies) a pair are present on the thorax 
and on each of the abdominal segments except the last (James, p. 25). 
