655 
1 882.] Colouration of Animals . 
Next, perhaps, in beauty to the Buprestidse — and if gifted 
with less command of wing, yet haunting flowers, and thus 
of necessity much exposed to the sun — come the Cetoniadse, 
of which our common rose-beetle ( Cetonia aurata) serves as 
a familiar type. Here also there are very numerous in- 
stances of a colouration on the lower surface of the insert 
rivalling or surpassing that of the upper. Among the ex- 
ceptions rank Doryscelis calcarata (Madagascar), where the 
under surface is black, whilst the elytra and pronotum are 
bright orange. Upon the whole it may be said that the 
results of an examination of this family tell in favour of 
Mr. Lewis, the upper and the lower surfaces being about 
equal in beauty. We have not, in the necessarily restricted 
survey we have been able to make, met with any distinct 
case of a Cetonian displaying iridescent colours above, and 
being of a black, a deep brown, or grey underneath. 
Mr. Lewis does not seem to have mentioned the interest- 
ing faCt that both among the Buprestidse and the Cetoniadse 
a few species have deep violet, bronze-green, &c., wings, 
though in the vast majority of beetles these organs are as 
colourless as those of a house-fly or a wasp. Careful ob- 
servation of the habits of these species may perhaps throw 
light on the cause of this anomaly. It will be remembered 
that in warm climates a great number of the Hymenoptera 
have beautifully coloured wings. 
Mr. Lewis, if we did not mistake him, referred also to the 
Phyllophaga, or, as they might be familiarly called, the 
cockchafer group, as being instances favourable to his views. 
This is strictly correct. Many of these inseCts, which are 
good flyers, are given to swarming over the tops of the trees 
and bushes on which they prey. Many of them have not 
only brilliant colours, but in such forms as Catalpa , Euchlora, 
Macraspis, &c., the lower surface is often equal, and often 
even superior to the upper in colouration. 
Other groups of the Coleoptera, however, supply much 
less favourable, or at least less decisive, evidence. If we 
turn to the common large dung-beetles of Britain, belonging 
to the genus Geotrupes, we find them black above, and richly 
coloured with violet, blue, deep green, and bronze under- 
neath. But this, according to the principles laid down by 
Mr. Lewis, is what we could scarcely expeCt. The inseCts 
in question fly little, save in the twilight. Much of their 
life is spent in underground burrows, or concealed under- 
neath the cakes of dung upon which they feed. Hence there 
is little opportunity for either of their surfaces to be exposed 
to the adtion of the light. As, further, we find them passing 
