298 POPULAR SCRIPTURE ZOOLOGY.

Emperors, it was so expensive, that under Tiberias it was
forbidden to be used by men: one of the most extravagant
charges brought against Heliogabalus is, that he was the
first man who wore a robe made entirely of silk; and the
Emperor Aurelian refused a silk dress to his consort on
account of the extravagant price.

Of course the moth Bombyx mori, and its larva, from
which all our silk is derived, was entirely unknown to the
Israelites. It is a whitish moth, with a broad pale brown
band across the upper wings. The larva is of a yellowish-
grey colour, and when full-grown about three inches long.
It feeds principally on the mulberry.

Orprk DIPTERA.

Cou1rex.—The Gnat.

The family Cudicida, to which this insect belongs, is dis-
tinguished by the length of the proboscis and by the beauti-
fully tufted antenne ; the larvee are inhabitants of the water,
in which element they move with great rapidity, coming to
the surface in order to breathe, which they do with the.
head downwards, as the respiratory apparatus is situated at