162 
SPOLIA ZBYLANICA. 
disturbed—in one position until their prey comes within striking 
distance. The lamellate organs then spring forward like the jaws 
of a rat trap, but almost instantly revert to their former position, 
the food being now held and manipulated by the proper mouth 
parts. 
Though well supplied with Gulex larvae, the young Toxorhyn- 
chites continued to prey upon each other until but a single survivor 
remained in each vessel. Having a habit of backing blindly 
about in the water, they sooner or later come within reach of 
the jaws of their companions. 
As the larva increases in size the body assumes a bright reddish 
tint above, the ventral parts remaining paler. The head and 
terminal parts become olivaceous brown. 
In spite of every attention and an ample supply of food, not a 
single larva reached maturity. I am consequently unable to state 
the time occupied in development from egg to mosquito. But the 
natural breeding-place of the insect was discovered : in the 
hollow stumps of the giant bamboos and in small pools in the 
angles of the branches of other trees, whence examples in all 
stages were obtained. Such natural receptacles of water are 
nearly always swarming with the larvae of various mosquitoes, 
more particularly with those of Stegomyia scutellaris and 
Desvoidea obturbans, and each receptacle usually contained a 
single larva of Toxorhynchites , seldom more than one, unless they 
were quite young. Many others had probably started life there, 
but—in the manner mentioned above—had gradually fallen 
victims to the strongest member. This fact will account for the 
comparative scarcity of the adult Toxorhynchites , and greatly 
minimizes its usefulness as a Culex destroyer. 
The fully grown larva of Toxorhynchites immisericors is a 
giant of its kind, averaging 16 mm. in length, and of a very 
robust build. It is of a dull reddish purple colour above, paler 
beneath ; opaque. Theobald gives a good figure of the larva 
(Mon. Culic., III., p. 118), but the remarkable raptorial organs are 
not displayed. The front of the head is deeply emarginate, and 
bears two fine simple bristles. The falcate lamellae now number 
nine on each side, and end in a simple curved point. The 
antennae are comparatively small and slender. They bear two 
fine hairs on one side, a little below the apex, and a few small 
points at the extremity. The body-bristles are very weakly 
plumose, and spring—in loose fascicles—from densely chitinous 
tubercles. There is a small but more densely plumose bristle on 
each side on the dorso-lateral area of the metathoracic segment. 
The stout respiratory siphon is of about the same length as 
