Holarctic spiders

Sittisax is a genus of spiders in the family Salticidae (jumping spiders).

Spiracme is a genus of crab spiders erected by Anton Menge in 1876 to contain S. striata, transferred from Xysticus.

species of arachnid

Leptorhoptrum is a monotypic genus of dwarf spiders containing the single species, Leptorhoptrum robustum. It was first described by C. Chyzer & Władysław Kulczyński in 1894, and has only been found in Japan, and Russia.

Estrandia is a monotypic genus of dwarf spiders containing the single species, Estrandia grandaeva. It was first described by H. H. Blauvelt in 1936, and has only been found in China, Japan, and Russia.

Canalidion is a monotypic genus of tangle-web spiders containing the single species, Canalidion montanum. The species was first described by James Emerton in 1882 under the name Theridion montanum. J. Wunderlich moved it to its own genus in 2018, because it had more teeth on the anterior margin of the cheliceral furrow, a basal depression of the cymbium, and an embolus positioned dorsally. It has a holarctic distribution.

Arctobius is a genus of tangled nest spiders containing the single species, Arctobius agelenoides. It was first described by Pekka T. Lehtinen in 1967, with a holarctic distribution.