Synonyms and other taxonomic changes
Explanation of Names
Perhaps named for a famous Roman Woman
(dead link), Ummidia Quadratilla
Saddle-like depression on tibia of third leg characteristic of this genus:
Species-level identification seems to be very difficult. Females, in general, cannot be keyed to species. Males can perhaps be keyed with a specimen and reference to keys. See Godwin and Bond (2021) for discussion.
Virginia south to Florida, west to Arizona, also neotropics.
Predatory on terrestrial invertebrates
Dig tunnel in ground and seal with a silk-hinged lid. They hide under this lid and make forays out when prey is sensed, presumably by vibration. Males are often found wandering in late spring, presumably looking for mates.
Chamberlin, R. V. & Ivie, W. (1945a). On some Nearctic mygalomorph spiders. Annals of the Entomological Society of America 38: 549-558.
Godwin RL, Bond JE (2021) Taxonomic revision of the New World members of the trapdoor spider genus Ummidia Thorell (Araneae, Mygalomorphae, Halonoproctidae). ZooKeys 1027: 1-165. https://doi.org/10.3897/zookeys.1027.54888
Roddy, L. R. (1957). Some spiders from southeastern Louisiana. Transactions of the American Microscopical Society 76: 285-295.
Photo from Baja California
--the well-concealed trapdoor