• Webster's Revised Unabridged Dictionary
    • n. pl Linguatulina (Zoöl) An order of wormlike, degraded, parasitic arachnids. They have two pairs of retractile hooks, near the mouth. Called also Pentastomida.☞ The adults of some species inhabit the nostrils and nasal sinuses of dogs and other carnivores. The young, after being swallowed by sheep, rabbits, etc., find their way to the lungs and liver and become encysted. These, when eaten by carnivores, develop into the adult forms.
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Century Dictionary and Cyclopedia
    • linguatulina A group, ordinal or other, of entoparasitic vermiform arachnidans, represented by the family Linguatulidæ, related to the mites or acarids, bear-animalcules or Arctisca, and Pycnogonida; the tonguelets, tongueworms, or fivemouths. In their mode of parasitism they singularly resemble cestoid worms, being found in the sexless or larval state in the lungs and liver of herbivorous animals, whence they are imported by carnivores, including man, in whose digestive and other passages they develop. The tonguelets are worm-shaped, ringed, and flattened; in the young state, when they resemble acarids, they have four legs, but when matured they have no external organs excepting two pairs of small hooks on the head, and a mouth. These hooks can be retracted into sheaths, the four openings of which, with the mouth, make five holes in the head, whence the alternative name of the creatures, fivemouths or Pentastomum. Another name is Acanthotheca, from the sheathing of the hooks. See cut under Pentastomida.
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Webster's Revised Unabridged Dictionary
NL., fr. L. lingua, tongue