New Mosquito from Fiji — Iaird 
349 
figures presented by Marks (194?) it appears 
that in all members of the kochi group, those 
having pointed comb spines distally as well 
as those having fringed scales only, the prox- 
imal rows of the comb consist exclusively of 
apically and laterally fringed scales. As, more- 
over, the pointed condition is least evident in 
the early instars, it may be postulated that the 
development of pointed spines in the distal 
row is a later development than that of fringed 
scales. Support for this hypothesis is to be 
derived from a wider study of the tribe Cuii- 
cini. Some of the more "primitive” members 
of this tribe (e.g., Toxorhynchites , Trichopro- 
sopon) lack a lateral comb altogether, others 
(e.g., Harpagomyia , Theobaldia) have a comb 
composed wholly of fringed scales, and for 
that matter the least specialized subgenera of 
individual genera often exhibit only fringed 
scales (e.g., Maorigoeldia of Tripteroides , Mu- 
cidus of Aedes) although the comb of their 
more advanced relatives may consist partly or 
wholly of pointed spines. Again, in the sub- 
genus Culex, generalized species such as C. 
annulirostris Skuse and C. tritaeniorhynchus 
Giles breed in a wide range of surface waters 
and their larvae have large numbers of small, 
fringed scales in the lateral comb; species 
which have clearly diverged from the gen- 
eralized ancestral stock, on the other hand — 
for example C. bitaeniorhynchus Giles and C. 
squamosus Taylor, the larvae of which are to 
be found in association with green filament- 
ous algae, and C. basicinctus Edwards, having 
larvae specialized for life amongst algae in 
flowing streams— -have the lateral comb made 
up of relatively small numbers of pointed 
spines. 
Accepting that the development of pointed 
spines in the distal row of comb teeth of 
members of the kochi group represents the 
specialization of a more generalized type of 
comb tooth, the fringed scale— and Marks 
(1947) noted that a larva of A . kochi itself 
from Nissan Island, at the eastern periphery 
of the range of this species, had one of the 
distal comb teeth apically fringed — there are 
good grounds for postulating that the devel- 
opment of baso-lateral spines on both types 
of teeth is likewise a specialization. Marks 
(1947) drew attention to the fact that the 
Philippine A. flavipennis (Giles) (which of all 
members of the kochi group exhibits least 
development of the larval specializations 
which characterize these insects) has only 
short scales with a rounded tip and a fine 
apical and lateral fringe in the distal row of 
the lateral comb. This may be viewed as being 
in accord with the general tendency for the 
more primitive representatives of the various 
animal groups to be found towards the peri- 
phery of the zone of dispersal, as may the 
distribution of the more southerly species of 
the kochi group lacking baso-lateral spines on 
the comb teeth, A. alocasicola , A. gahnicola , 
and A. freycinetiae . 
The morphology of the last-named species, 
particularly the primitive type of fringed scale 
in the distal row of the larval lateral comb and 
the slender and scarcely specialized seta of the 
male coxite, suggests that this insect might 
be close to the parent stock from which both 
of its nearest relatives, A . samoanus and A. 
fjiensis , have evolved. This hypothesis gains 
weight from the fact that the larval habitat of 
A. freycinetiae is an indigenous forest plant in 
the axils of which the parent stock could well 
have persisted in ecological isolation long 
after an evolving sympatric species had in- 
vaded various large species of Pandanus. Spe- 
cies of Freycinetia and Pandanus form part of 
the indigenous Fijian flora, and ample time 
has thus been available for the development 
of the various morphological differences 
which at once separate A. fjiensis from A. 
freycinetiae; but much less time can have 
operated in the case of the closest relative of 
the latter species, A. samoanus , which cus- 
tomarily breeds in the axils of Colocasia and 
Alocasia spp., plants owing their distribution 
throughout the South Pacific to human agency. 
Buxton and Hopkins (1927) found it "not 
easy to understand why the typical A. kochi , 
breeding in coco-nuts, should give rise to 
