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A minute arachnid, of the order Acarina, of which there are many species; as, the cheese mite, sugar mite, harvest mite, etc. See Acarina.

Same as Arachnida.

ler; especially, one of the jointed sense organs attached to the mouth organs of insects, arachnids, crustaceans, and annelids; as, the mandibular palpi, maxillary palpi, and labial palpi. The palpi of male spiders serve as sexual organs. Called also palp. See Illust. of Arthrogastra and Orthoptera.…

A division of Arachnida, including the whip scorpions (Thelyphonus) and allied forms. Sometimes used in a wider sense to include also the true scorpions.

One of the second pair of mouth organs of arachnids. In some they are leglike, but in others, as the scorpion, they terminate in a claw.

Any arachnid that breathes by lunglike organs, as the spiders and scorpions. Also used adjectively.

Any one of numerous species of pulmonate arachnids of the order scorpiones, having a suctorial mouth, large claw-bearing palpi, and a caudal sting.

A division of arachnids comprising the scorpions.

A division of arachnids having large, powerful fangs and a segmented abdomen; -- called also Solpugidea, and Solpugides.

Any one of numerous species of arachnids comprising the order Araneina. Spiders have the mandibles converted into poison fangs, or falcers. The abdomen is large and not segmented, with two or three pairs of spinnerets near the end, by means of which they spin threads of silk to form cocoons, or nests, to protect their…

external openings communicating with the air tubes or tracheæ of insects, myriapods, and arachnids. They are variable in number, and are usually situated on the sides of the thorax and abdomen, a pair to a segment. These openings are usually elliptical, and capable of being closed. See Illust. under Coleoptera.…

One of the apertures of the pulmonary sacs of arachnids. See Illust. of Scorpion.

A small scarlet arachnid.

An order of minute aquatic arachnids; -- called also bear animalcules, sloth animalcules, and water bears.

A division of Arachnida including those spiders which have four lungs, or pulmonary sacs. It includes the bird spiders (Mygale) and the trapdoor spiders. See Mygale.

The second, or middle, region of the body of a crustacean, arachnid, or other articulate animal. In the case of decapod Crustacea, some writers include under the term thorax only the three segments bearing the maxillipeds; others include also the five segments bearing the legs. See Illust. in Appendix.…

One of the respiratory tubes of insects and arachnids.

A division of Arachnida including those that breathe only by means of tracheæ. It includes the mites, ticks, false scorpions, and harvestmen.

on which the warp threads rest. -- Whip scorpion (Zoöl.), any one of numerous species of arachnids belonging to Thelyphonus and allied genera. They somewhat resemble true scorpions, but have a long, slender bristle, or lashlike organ, at the end of the body, instead of a sting. -- Whip snake (Zoöl.), any one of vario…