4 
united to the fourth long vein by the posterior cross-vein ; the 
sixth long vein is simple and sinuous ; the second and third long 
veins may be prolonged into the first basal cell, which is usually- 
large, but smaller in Megarhinus ; the sub-costal transverse is 
always present, but not always readily seen, whilst the second 
long vein is united to the first by the marginal transverse ; there 
are one (Culex) or two (Megarhinus) indistinct incrassations of 
the wing membrane representing branches of the fourth trunk, 
which never reach the margin of the wing, and are never pro- 
vided with scales ; in the $ 's the fork cells are usually much 
smaller than in the $ 's (especially in Culex and Anopheles) ; 
the wings are recumbent in repose, and may or may not be longer 
than the abdomen. 
The legs are long, but not so long as in the Tipulida?, the 
hind metatarsus being usually long ; the ungues are nearly always 
equal and small in the ? , and may or may not be toothed ; in 
the $ the fore and mid-ungues are unequal and are toothed in 
various ways, but have rarely more than two serrations ; the 
hind ones are always equal ; the legs are scaly, except the coxa? 
and trochanters, which are usually nude, but with occasional 
patches of squama?. The chief characters by which the Culicidae 
are distinguished are : — 
(1) The piercing mouth ; 
(2) The scaled veins, head, thorax, body, etc. 
(3) The venation composed of six distinct longitudinal 
veins (in Heptaphlebomyina? seven), and two prominent 
fork-cells, with their covering of scales, the costal vein 
being carried right round the edge of the wing. 
The family is divided by Theobald into ten sub-families, 
characterised as follows : — 
SUB-FAMILY 1 — ANOPHELINiE. 
In this sub-family the scutellum is simple, never trilobed ; 
the palpi are long in the $ and % , and the larva? have no res- 
piratory siphon. The head never has flat lateral scales. 
The genera may easily be told by the squamose characters 
of head, thorax, abdomen and wings. It contains the following 
genera : — Anopheles, Myzomyia, Cycloleppteron, Feltinella, 
Stethomyia, Pyretophorus, Myzorhy nchella, Arribalzagia, 
Myzorhynchus, Chrystia, Lophoscelomyia. Nyssorhynchus, Cellia, 
Neoeellia, Aldrichia, Kerteszia, Bironella, Chagasia, Pseudomy- 
Eomyia. 
SUB-FAMILY 2. — MEGARHININ^E. 
In this sub-family the proboscis is strongly re-curved ; 
head and scutellum densely clothed with flat scales. The palpi 
of the ? may be short or long. The first sub-marginal cell is 
very small. It contains the genera Megarhinus, Ankylorhynchus, 
Toxorhynchites. 
