326 
to the structure of the trumpets and the want of the above-mentioned 
hairs, it must be regarded as very probable, that the supposition 
Is. Correct. 
The eggs of Mansonia have been described by different authors 
(see Dyar and Knab 1910 p. 259). Further they have been 
thoroughly described by the said authors in a special paper (1916 
p. 61). The following remarks are taken from that paper. The 
eggs of the three American species M. fasciolalus, Arrib., arribålzagæ 
Theob., and perlurbans Walk., do not differ very much in shape, 
arrangement, and manner of disposal from eggs of typical Culeæ. 
The egg-boats fløat upon the surface of the water, one end usually 
resting against an aquatic plant; still there is some difference in 
the arrangement of the eggs of the three species. The eggs of 
M. titillans found by Moore, are of quite another type; they 
are placed on the under-surface of the leaves of Pistia and deposited 
in a mass, generally between ribs of the leaves. They are attached 
to the leaves with their bases very closely crowded together and 
apparently kept by a cement secreted by the female. The number 
of eggs in a cluster exceeds 150. Moore has observed directly, 
that at least the abdomen was submersed when ovipositing. "The 
lower half of her abdomen was submerged and bent or curved 
back, the segment somewhat extended, and was being moved slowly 
from side to side the eggs seeming to issue forth in rapid succession 
and to be as rapidly set up each in its place . . . air bubbles 
were entangled in the abdominal scales and on the leaf itself. 
According as the cluster enlarged in her direction she drew her 
abdomen more and more up, so that when she finished at 6,35 
not much more than the tip of it was curved under the leaf. When 
she first started more than half of her abdomen would have been 
under the water. The freshly laid cluster was white". Dyar and 
Knab call attention to the fact, that the abdomen of the female 
of M. titillans is unusually hairy, the hairs being well distributed 
and coarse. This is no doubt an adaptation that, by entangling, 
the air between the hairs prevents the body itself from becoming 
wet while immersed. Moore supposes that the female, when at 
work on Pistia, really works in a globule of air, for, owing 10 
the dense pilosity of the leaf, the under-surface is simply aglow 
with air-bubbles, so that the leaf probably rests more on air than 
