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Have you a desire for a more intimate knowledge of the animal, take him up by the big claw, and you can now examine him without the least fear of incurring the proofs of his displeasure. Two bead-like, compound eyes, supported on long stalks, which can be readily withdrawn into the protecting shield of the carapace, will be observed. From the manner of this support, which allows of vision in almost every direction, the name of stalk-eyed crustaceans has been given to the group in which this structure is found. The two pairs of feelers, which you see in front of the eyes, are known as antennæ and antennules. They are of peculiar interest, for, aside from acting as feelers, they subserve the functions of smelling and hearing, the auditory apparatus being lodged in the base of the smaller pair. There are ten feet, and this is a character of importance, as it is a feature distinctive of the ten-footed, or decapod, crustaceans. At first sight it appears that the animal is devoid of a tail, but if you turn him over upon his back you will find a very short one tucked safely under the body. A comparison of our study of this crab with that of the lobster or cray-fish will show that the tail, or, more properly, the abdomen, is stretched out beyond the body proper, and that the elongation is in proportion to the length of the animal. Two distinct groups of ten-legged, stalk-eyed crustaceans are thus recognized, namely: the short-tailed forms, or crabs, and the opposite, or long-tailed forms, to which the lobster and shrimp belong, the hermit-crabs constituting an intermediate type.