Ummidia Thorell, 1875

Godwin, Rebecca L. & Bond, Jason E., 2021, Taxonomic revision of the New World members of the trapdoor spider genus Ummidia Thorell (Araneae, Mygalomorphae, Halonoproctidae), ZooKeys 1027, pp. 1-165 : 1

Genus Ummidia Thorell, 1875

Ummidia Thorell, 1875.

Pachylomerus Ausserer, 1871.

Diagnosis.

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.

General description.

Small to large trapdoor spiders. Cephalothorax longer than wide. Pars cephalica highest behind the eyes and sloping posteriorly. Carapace evenly sclerotized; rough/rugose in males, smooth/shiny in females. Fovea procurved, and deep. At least median eyes on tubercle, eye diameter variable. Anterior eye row procurved, posterior eye row relatively straight to slightly recurved or procurved. Carapace of ethanol preserved specimens yellow, reddish, or dark brown. Living spiders usually black to very dark brown. Abdominal coloration generally dark grey, occasionally with a bright white dorsal patch, pale opalescence, or light patches at apodemes.

Sternum usually approximately as wide as long. Lacking lateral sigilla, posterior sigilla large, central, and indistinct. Palpal endites and labium usually with cuspules, size and number of cuspules variable. Palpal endites longer than wide and without anterior lobe. Chelicerae biserially dentate, cheliceral rastellum generally consisting of large spines on a mound.

With two pairs of spinnerets. Posterior median spinnerets (PMS) short and unsegmented. Posterior lateral spinnerets (PLS) relatively short and three segmented with apical segment shortest and domed. Females with single-lobed spermathecae, which are lightly sclerotized with apical bulb. Male palpal bulb with thin embolus.

Females lacking scopulae, but palps, legs I & II with numerous curved, thorn-like spines laterally. Males with scopulae on legs I & II, tarsi cylindrical to proximally enlarged. Anterior legs with few to many prominent spines on the tibia, metatarsus, and tarsus. Posterior legs stouter with heavy spines. Tibia III with dorsal, glabrous, saddle-like depression. Tarsi with mix of clavate and filiform trichobothria arranged in wide band.

Distribution.

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.

Keys to males by region.

As with many members of Mygalomorphae , the highly conserved morphology of Ummidia makes identification non-trivial. In addition, females in particular frequently lack reliably identifiable characters of any sort. The authors have provided keys to the males of species divided by region with notes on females where appropriate, but it should be noted that the keys should be used in combination with other information, to include species descriptions, knowledge of the specimen’s locality, and, for males, the season in which it was collected. In addition, for the reasons mentioned above, there is no key to Ummidia of South America and the Caribbean due to the lack of male material for all species except Ummidia asperula .