The Descent of Man

Rhagium, and the Leptura testacea; the male of
the latter being testaceous, with a black thorax,
and the female of a dull red all over. These two
latter beetles belong to the family of Longicorns.
Messrs. R. Trimen and Waterhouse, jun.,
inform me of two Lamellicorns, viz., a Peritrichia
and Trichius, the male of the latter being
more obscurely coloured than the female. In
Tillus elongatus the male is black, and the female
always, as it is believed, of a dark blue
colour, with a red thorax. The male, also, of
Orsodacna atra, as I hear from Mr. Walsh, is
black, the female (the so- called O. ruficollis)
having a rufous thorax.), which I saw in Mr.
Bates's collection, are generally redder but rather
duller than the females, the latter being
coloured of a more or less splendid goldengreen.
On the other hand, in one species the
male is golden-green, the female being richly
tinted with red and purple. In the genus Esmeralda
the sexes differ so greatly in colour that
they have been ranked as distinct species; in