Theridiosoma is a genus of ray spiders that was first described by Octavius Pickard-Cambridge in 1879. They use their web as a high speed slingshot to actively hunt for prey.
Anapidae is a family of rather small spiders with 232 described species in 58 genera. It includes the former family Micropholcommatidae as the subfamily Micropholcommatinae, and the former family Holarchaeidae. Most species are less than 2 millimetres (0.079 in) long.
Castianeira is a genus of ant-like corinnid sac spiders first described by Eugen von Keyserling in 1879. They are found in Eurasia, Africa, and the Americas, but are absent from Australia. Twenty-six species are native to North America, and at least twice as many are native to Mexico and Central America.
Theridion is a genus of tangle-web spiders with a worldwide distribution. Notable species are the Hawaiian happy face spider (T. grallator), named for the iconic symbol on its abdomen, and T. nigroannulatum, one of few spider species that lives in social groups, attacking prey en masse to overwhelm them as a team.
Kaira, sometimes called frilled orbweavers, is a mostly neotropical genus of orb-weaver spiders first described by O. Pickard-Cambridge in 1889. It includes sixteen described species that occur from South America up to the southern and eastern USA. It is presumably related to Aculepeira, Amazonepeira and Metepeira.
Mallos is a genus of cribellate araneomorph spiders in the family Dictynidae, and was first described by O. Pickard-Cambridge in 1902. Among the genus, Mallos gregalis is known to be a social spider species, living in groups and signaling each other by vibrating their web.
Cryptachaea is a genus of spiders in the Theridiidae family.
Metepeira is a genus of orb-weaver spiders first described by F. O. Pickard-Cambridge in 1903. The name is derived from the Ancient Greek μετά and the obsolete genus name Epeira, denoting a genus similar to Epeira.
Dictyna is a genus of cribellate araneomorph spiders in the family Dictynidae, and was first described by Carl Jakob Sundevall in 1833.
Euryopis is a genus of comb-footed spiders that was first described by Anton Menge in 1868.
Herpyllus is a genus of ground spiders first described by Nicholas Marcellus Hentz in 1832.
Glenognatha is a genus of long-jawed orb-weavers that was first described by Eugène Louis Simon in 1887. It was considerably revised in 2016.
Linyphia is a genus of dwarf spiders that was first described by Pierre André Latreille in 1804. The name is Greek, and means "thread-weaver" or "linen maker".
Segestrioides is a genus of South American coneweb spiders that was first described by Eugen von Keyserling in 1883. Originally placed with the recluse spiders, it was moved to the coneweb spiders in 1983.
Micaria is a genus of ground spiders that was first described by Niklas Westring in 1851. They are 1.3 to 6.5 millimetres long.
Trachelas is a genus of araneomorph spiders originally placed with the Trachelidae, and later moved to the Corinnidae.
Scopoides is a genus of ground spiders that was first described by Norman I. Platnick in 1989.
