Euctenizidae

The Euctenizidae (formerly Cyrtaucheniidae subfamily Euctenizinae) are a family of mygalomorph spiders. They are now considered to be more closely related to Idiopidae.

Etymology
The name comes from the Greek prefix εὖ- (eu-), meaning "valuable" or "good", which had been thought that the family Ctenizidae possess these traits.

Biology
Many, but not all, make wafer-like doors to their burrows, while others build the cork-like doors found commonly in the true trapdoor spiders. The biology of nearly all of the species is poorly known.

Distribution
The family occurs almost exclusively in the United States and Mexico. Common U.S. genera include Myrmekiaphila, Aptostichus and Promyrmekiaphila.

Genera
, the World Spider Catalog accepts the following genera:


 * Apomastus Bond & Opell, 2002 — United States
 * Aptostichus Simon, 1891 — United States, Mexico
 * Cryptocteniza Bond & Hamilton, 2020 — United States
 * Entychides Simon, 1888 — United States, Mexico
 * Eucteniza Ausserer, 1875 — Mexico, United States
 * Myrmekiaphila Atkinson, 1886 — United States
 * Neoapachella Bond & Opell, 2002 — United States
 * Promyrmekiaphila Schenkel, 1950 — United States