254 THE ZOOLOGIST. 
In the insect world we find that many Lepidoptera for which 
birds have a liking gradually adapt themselves, by the survival 
of the least conspicuous, to their surrounding conditions as 
regards colour and markings, so that they are not readily dis- 
covered by their enemies, and therefore escape extermination, 
which would certainly ensue did they combine the qualifications 
of being easily seen and being attractive also as a dainty morsel. 
On the other hand, some insects, owing to their bitter or other- 
wise disagreeable flavour, are not sought for by birds, and these 
are consequently enabled to develop brilliant colours, as in the 
case of the common Garden Tiger moth, Arctia caja. 
Now it is curious that this theory does not hold good with 
the crustacean Nephrops norvegicus, for although an animal of a 
striking colour living in a dull region, and a region, moreover, 
swarming with crustacean-eating fish, it is one of the most palat- 
able and favourite foods of these fish, as it is also a recognised 
and rather valuable article of human food. It is possible that 
there may be conditions of which we are ignorant that enable this 
species to reproduce itself to a greater extent than is the case 
with others, but whatever these conditions may be, it is certain 
that a species which is a favourite food for fishes, and one readily 
distinguished on account of its prominent colour by its enemies, 
is able to hold its own in the struggle for existence under the, 
apparently, most disadvantageous circumstances. 
The carapace of the Norway Lobster differs considerably 
from the common or marketable lobster; it is slender and 
elongated, pink in colour, and flattened at the sides in the 
cephalo-thoracic region; the abdominal somites are barred with 
a darker colour, and the tail-plates are rather broad and fan- 
shaped. The anterior pair of legs, or claws, are unusually long, 
deeply furrowed, and the ridge armed with spines; the difference 
in size between the right and left claw is not so marked as in the 
common lobster; the pincers are also elongated, the inner edges 
being tuberculated in the larger claw and more finely toothed in 
the smaller. The second and third pairs of legs are armed with 
small pincers, but the fourth and fifth pairs terminate in a simple 
claw. The rostrum is long and strongly toothed, the antenne 
long and slender, and the eyes are unusually large and kidney- 
shaped,—another rather striking peculiarity, considering that 
Nephrops norvegicus is a somewhat deep-water species, under 
