trapdoor spider

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of various insect-eating spiders of the family Ctenizidae, found in warm climates, that construct a silk-lined burrow concealed by a hinged lid.

Wiktionary

1. n. any spider, of the family Ctenizidae, that constructs a silk-lined burrow with a hinged lid

GNU Webster's 1913

1. n. (Zoöl.) any one of several species of large spiders which make a nest consisting of a vertical hole in the earth, lined with a hinged lid, like a trapdoor. Most of the species belong to the genus Cteniza, as the California species (Cteniza Californica).