13 
evident that the larvae of these genera are very similar in structure and appear- 
ance. They all adopt a horizontal attitude. All have specially modified mouth 
parts and possess conspicuous “ clasping organs’”’ in place of the feeding 
brushes. The general appearance in allis similar; the shape of the head and 
clypeus is identical. The anal papillz are rudimentary or absent. 
Muczdus scataphagotdes—The full grown larva is very large, and its 
horizontal attitude and the curious truncated appearance of the head are 
characteristic. 
The head is smooth and globular. Three long, conspicuous hairs arise on 
each side. These differ from hairs in other larve in not being branched. The 
clypeus overhangs the mouthand forms a curious concave edge, and not, as in 
non-cannibal larvee, a prominence. On each side of the clypeus a modified feed- 
ing brush arises. 
The feeding brushes are highly modified and form clasping organs. When 
the larva is at rest, they project laterally as dark, horn-like structures. Each brush 
is composed of a number of slightly curved chitinous bars, which have minute 
comb-like projections on the concave side (PI. III, fig. 14). The bars lie gene- 
rally closely approximated, so that the clasping organ at first sight appears to 
be composed of a single dense piece of chitin. The mental plate in both Mucz- 
dus and C. concolor is very similar and differs widely from that of any other larva 
I have seen. In both species it carries only a few teeth, but these are of great 
size (PI. III, figs.5and 6). In Muczdus the maxillary palps are very small and 
do not cover in the mandibles as in non-carnivorous species. The mandibles 
are conspicuous, and the mandibular plate is very solid and massive. 
The antennz are small and resemble in general appearance those of 
Stegomyia. The small basal tuft, however, rises very near the termination of 
the antenna. The median and terminal spines are represented by a few 
inconspicuous processes. There are a few small spines scattered over the 
antenna (PI. II, fig, 12). 
The thorax is smooth and globular. The hairs arising from it and also 
the hairs arising from the abdomen are simple and spring from well-marked and 
chitinised papilla. The siphon tube is long, the siphonic index being 4°6. 
There are about 22 spines in each row and two conspicuous tufts of hairs above 
these. There is no rudder-like fan of hairs rising from the median line as in 
C. concolor and C. tzgrzpes. The ninth segment differs from that of most larve 
in possessing only rudimentary anal papilla. The ventral fan of hairs has also a 
more extended origin (PI. III, fig. 16). 
Megarhinus and Toxorhynchites—The larva of 7. spectosus figured by 
Theobald corresponds in almost every detail with the above description. The 
chief differences are in the presence of short, ‘notched hairs arising from the 
