Description
Ummidia species are small to large trapdoor spiders, usually black to very dark brown in color. The abdominal coloration is generally dark grey, occasionally with a bright white dorsal patch, pale opalescence, or light patches at the apodemes. The cephalothorax is longer than it is wide. The pars cephalica is highest behind the eyes and sloping posteriorly. The carapace is evenly sclerotized, and is rough in males and smooth in females. The fovea is procurved and deep. At least the median eyes are on the tubercle, with the eye diameter being variable. The anterior eye row is procurved, while the posterior eye row is relatively straight to slightly recurved or procurved. The sternum is usually approximately as wide as it is long.
Ummidia can be differentiated from all other halonoproctid genera except Conothele by the presence of a dorsal, glabrous, saddle-like depression on tibia III. Ummidia can be further distinguished from Bothriocyrtum, Cyclocosmia, and Hebestatis by the presence of clavate trichobothria and the absence of lateral sternal sigilla.
Distribution and habitat
Ummidia is a wide-ranging genus, found in the southwestern Mediterranean, Central Asia, and in the Americas from as far north as Ohio and Maryland west to Arizona and south to Brazil, including the Greater and Lesser Antilles. Ballooning, a peculiar behavior among most mygalomorphs, has been observed in a few species. This behavior explains the genus' presence on multiple islands in the Caribbean, including the volcanic island of St. Vincent and possibly Bermuda.
Ummidia spiders construct silk-lined burrows, usually with cork-type doors. These burrows are cryptic and difficult to find and are often covered in leaf litter.
