The Collaborative International Dictionary of English v.0.48:

Mygale \Myg"a*le\, prop. n. [L., a field mouse, Gr. ?.] (Zool.)
   A genus of very large hairy spiders of the family
   Ctenizidae, having four lungs and only four spinnerets.
   They do not spin webs, but usually construct tubes in the
   earth, which are often furnished with a trapdoor. The South
   American bird spider (Mygale avicularia), and the crab
   spider, or matoutou (Mygale cancerides) are among the
   largest species. They are also called trapdoor spiders.
   Some of the species are erroneously called tarantulas, as the
   Texas tarantula (Mygale Hentzii).
   [1913 Webster +PJC]