29 
Structure of Larvae. 
and sometimes as large and as broad as the thorax. The 
abdomen is nearly the same width all the way down, but the chief 
difference is in the much shorter and broader respiratory siphon 
and its black colour. Colonel - Giles’s figure of the larva 
(Fig. 16, III.) of Stegomyia pseudotaeniafa will also be seen to 
have the same characters, the respiratory tube only being about 
equal to one and a third segments in length. 
Aedes and Uranotaenia larvae. —The only observations 
on Aedes I know of seem to show that the larvae are like Cut ex,* 
but smaller. Dr. Lutz sends me a rough figure and note on the 
larvae of Uranotaenia. The larva, he says, is very much like that 
of Anopheles, but has a short breathing tube, and lies obliquely 
in the water, something between Anopheles and Culex in 
position. 
Mochlonyx larva (Fig. 19).—Meinert has given us a good 
description of the Mochlonyx larva. The full-grown larva is of a 
light brown colour, with greyish or reddish shades, with air-bags 
and tracheal stems showing through the upper surface, sometimes 
quite brown or almost golden in colour. On the opposite side 
of the thorax are found several dull white spots, and when the 
pupal period approaches the sides of the thorax also become 
white ; the under side of the larva is greyish ; the tail-fan and 
anal bristles and eyes are all nearly black. With the different 
changes of skin the head and anal tube come out quite white, 
but gradually darken again. 
The head is broad, but not so broad as the thorax ; it is 
much pinched in anteriorly ; in front project four long, many- 
rayed bristles; the eyes are placed rather far back on the 
broad part of the head; antennae thick, one-jointed, and are 
fixed on to small projecting tubercles. They end in four long, 
bent bristles, not much longer than the antennae themselves. 
One bristle is very short, and there is also another short, thick 
jointed bristle. The mouth parts are well formed, the mandibles 
are strong, and bear not only teeth, but a variety of simple and 
compound hairs. The thorax is large, somewhat flattened, with 
a few fan-like bristles on the sides, much wider than the head or 
abdomen. 
* I cannot find this reference, but it is on the authority of Baron Osten- 
Sacken, and probably refers to Aedes fuscus, of America and Canada. 
