What is "pentastomida"

Linguatulina \Lin*guat`u*li"na\ (l[i^][ng]*gw[a^]t`[-u]*l[imac]"n[.a]), n. pl. [NL., fr. L. lingua tongue.] (Zo["o]l.) An order of wormlike, degraded, parasitic arachnids. They have two pairs of retractile hooks, near the mouth. Called also Pentastomida.

Note: 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.

Pentastomida \Pen`ta*stom"i*da\, n. pl. [NL., fr. ? (see Penta-) + ? a mouth.] (Zo["o]l.) Same as Linguatulina.

Pentastomida are an enigmatic group of parasitic invertebrates commonly known as tongue worms due to the resemblance of the species of the genus Linguatula to a vertebrate tongue.

There are about 130 extant species of pentastomids; all are obligate parasites with correspondingly degenerate anatomy. Adult tongue worms vary from about in length, and parasitise the respiratory tracts of vertebrates. They have five anterior appendages. One is the mouth; the others are two pairs of hooks which they use to attach to the host. This arrangement led to their scientific name, meaning "five openings", but although the appendages are similar in some species, only one is a mouth.

Alternative names for the Pentastomida include Pentastoma (strictly a genus name), Linguatulida, and Acanthotheca.