THE SENTINEL-CRAB. 
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limbs held in such an attitude that they offer scarcely any resistance to the element in which - 
the creature lives. 
This species has a very wide range, and is found throughout the warmer seas. It is 
common around India, Australia, and the Philippines, and from its bird-like fleetness and 
activity, has never failed to attract attention. Like others of its family, it feeds upon living 
prey, and chases its victims through the water with a speed as rapid, an aim as certain, and a 
voracity as unfailing as are exhibited by the shark itself. The species is notable for the shape 
of the carapace, and the sharp spine into which each side is developed. 
The Edible Crab of America {Neptunus hastatus) forms a somewhat important item of 
commerce in certain portions of our coast. In New England, north of Cape Cod, it is prac- 
tically unknown as an edible. When in the soft state, after moulting, it is highly prized, and 
ranks even higher than the best oysters. They are not produced in sufficient numbers to 
render them common in markets, excepting those of the Middle States. The region of 
Hampton Koads is the central point of this luxury. This species is also consumed largely 
in its hard-shell state. It extends southward to the Gulf of Mexico, where it is abundant on 
the reef. 
Another strange-looking creature is nearly as good a swimmer as the oceanic crab, 
and has many of the same habits. Like that crustacean, the Forceps-ckab roams the ocean 
as freely as the bird roams the air, shooting through the waves with arrowy swiftness in chase 
of prey, gliding easily along just below the surface, hanging suspended in the water while 
reposing, or occasionally lying across some floating sea- weed. The chief peculiarity of the 
Forceps-crab is the structure Horn which its name is derived, the wonderful length of the first 
pair of limbs, and the attenuated forceps with which they are armed. Though not possessing . 
the formidable power with which some crabs are armed, the Forceps-crab is yet as terrible an 
enemy to the inhabitants of the sea, for it can dart out these long claws with a quick rapidity 
that almost eludes the eye, and grasp its prey with unerring aim. 
No one who has not watched the crabs in their full vigor and while enjoying their 
freedom, can form any conception of the many uses to which the claws are put and the 
wonderful address with which they are used. Their bony armor, with its powerful joints, 
appears to preclude all delicacy of touch or range of distinction, and yet, the claws are 
to the crab what the proboscis is to the elephant. With these apparently inadequate 
members the crab can pick up the smallest object with perfect precision, can tear in pieces 
the toughest animal substances, or crack the shell of other crustaceans as a parrot cracks a 
nut in its beak. It can direct them to almost every part of its body, can snap with them like 
the quick, sharp bite of a wolf, or can strike with their edges as a boxer strikes with his fists. 
The paddle-legs are broad and well developed, so as to ensure speed, the front of the cara- 
pace is sharply and deeply serrated, and the sides are drawn out into long pointed spines. It 
is a native of the West Indian seas, and is represented about the dimensions of an ordinary 
specimen. 
The Nipper-ceab {Polybius henslowii) is a better swimmer than the fiddler-crab, being 
able, according to Mr. Couch’s account, to ascend to the surface of the sea, and to pursue its 
prey through the waters. So well does this creature swim, and so voracious is its appetite, 
that it captures and eats even the swiftest sea-fish, having been known to pounce upon the 
mackerel and the pollack. Its method of proceeding seems to be to dart upon its prey, grasp 
it firmly with its sharply -pointed and powerful claws, and retain its hold until the unfor- 
tunate victim is quite fatigued and falls an easy prey. It is not so handsome as the velvet 
fiddler, having none of the beautiful scarlet and azure tints which decorate that species, and 
being mostly colored with different shades of brown. 
Our last example of this interesting family is the Sentinel-crab, so called from its 
extreme watchfulness, and the wonderful manner in which its eyes are arranged so as to 
explore objects in every direction, without needing to move, or even to raise itself from its 
flat and crouching attitude. The generic name of this creature is of Greek origin, being- 
composed of two words, the former signifying a foot, and the latter an eye, and is given to it 
on account of the strangely long footstalks on which the eyes are set. When the creature is 
