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Page:Popular Science Monthly Volume 54.djvu/628

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POPULAR SCIENCE MONTHLY.

plate), and not infrequently are the same in number as the legs. Not a few are fitted with poison sacs and fangs, and in the case of some of the larger true spiders and scorpions the venom is very virulent, and in some instances has proved fatal to human life.

As this is hardly the place for a technical description of my Thelyphonus—a female—I shall content myself with a few facts and measurements. Those who are curious as to her personal appearance can consult the accompanying photograph. Most persons will conclude that her beauty is not even "skin deep."

The following post-mortem data will perhaps aid in giving a clearer idea of this curious little creature. The length of the body from the front of the cephalo-thorax to the end of the last post-abdominal segment was fifty-two millimetres—a little more than two inches; the length of the tail was fifty millimetres, thus making the total length about four inches. The width of the abdomen in its widest part, near the center, was thirteen millimetres, or approximately half an inch. The claw-bearing palpi, or "feelers," which are large and very powerful, have an extreme expansion of fifty-eight millimetres, nearly two and a half inches. The tail is a curious organ, and consists of forty-four short, jointed sections of a pale wine color, with a light yellow ring at the base; a few short, scattered pointed hairs are found on each segment. It is about two thirds of a millimetre in thickness at the base and tapers to about half this diameter at the end. When alarmed, the Thelyphonus holds it curved over forward after the manner of the true scorpions; a habit that probably points to some common ancestor. Its true function appears to be that of an extra palpus or "feeler."

The Thelyphonus is generally of a wine color. In some places, as on the cephalo-thorax, this color is black; around the mouth parts, the legs, the sternal plate, and the under side of the abdomen, this wine color is very pronounced.

The eyes are eight in number. Two of them are close together, on opposite sides of a slightly elevated ridge at the front of the cephalo-thorax. These eyes are bright, black, and beadlike, and about two thirds of a millimetre in diameter. A little farther back,