CONCEALMENT AND COLORS IN CRUSTACEA—MINKIEWICZ. 467 
Of this entire group I personally know in life 14 species belong- 
ing to the genera Stenorynchus, Inachus, Acanthonyx, Maja, Pisa, 
and Lambrus. But although I have made observations on several 
different species, I shall speak in this article of only two, both 
belonging to the genus Maja Lamarck (d/. verrucosa Milne-Edwards 
and MW. squinado Uatreille), species very closely 
allied and with identical habits. 
Il. THE SELF-CONCEALMENT OF THE CRABS. 
With reference to Hyas araneus Linneus, a 
species of the family Majid, the process of con- 
cealment has been very accurately described by 
Carl Aurivillius. It is almost identical with that 
of the species of J/aja, which is described below: 
Having found an alga (of any kind, red, brown, 
or green, depending upon circumstances), the crab 
seizes it with its long, slender claws, puts it first 
Fie. 5.—Left claw 
recurved on the 
into its mouth, and, while holding it by one end 
with its maxillipeds, begins to tear it to pieces 
with its two claws, one drawing it toward its cara- 
pace, the other pushing it away. 
back of the animal 
and scraping the 
hooks of the last 
group of the upper 
left line. (Hyas 
araneus L.) 
When a piece, the size and form of which may 
vary indefinitely, has once been cut off, the crab pushes it with 
one of its claws between its maxillipeds and whirls it around 
several times, acting as if it were its prey—a mussel or a piece of 
fish. 
After having rumpled it, it takes it again with one of its claws 
(indifferently with the left or the right), then extends the claw 
forward as far as possible, and, 
after making a rotary motion, 
bends it around over its back¢ 
and proceeds to affix the alba upon 
a group of dorsal hooks, rostral, 
branchial, ete., moving the claw 
slightly back and forth until the 
alga hooks on. Sometimes it at- 
taches it on the outer surface of 
the ambulatory feet, which are 
similarly provided with hooks, by flexing the foot and bending it 
under the ventral face of the carapace. 
I have more than once shown this operation to my fellow-laborers 
in the laboratories of Villefranche-sur-Mer and of Roscoff. 
Fie. 6.—Right claw curved under the 
ventral surface of the animal toward 
the branchial hooks of the left side. 
(H. araneus L.) 
“This movement is seen only in the crabs under consideration. 
