Two gnaphosid species, Heser infumatus (O. Pickard-Cambridge 1872) and Hongkongia reptrix Deeleman-Reinhold 2001, are reported as new records from Japan. The genera Heser Tuneva 2004 and Hongkongia Song & Zhu 1998 are recorded from Japan for the first time. Heser infumatus is distinguished from the other Japanese species of the subfamily Zelotinae by the epigyne with a pair of transvers furrows (copulatory openings) in median part. Hongkongia reptrix is separated from the other Japanese gnaphosids by having the posterior eyes closely situated to one another, the posterior eye row distinctly procurved, and the long spinnerets.
A new scytodid species of the genus Stedocys is described as Stedocys amamiensis sp. nov. from Amami-Ôshima, Japan. This species is similar to S. gaolingensis Wu & Li 2017 from China, but can be distinguished from it by having stouter embolus and abdominal markings on the midline. The genus Stedocys is newly recorded from Japan, and this record is the northeasternmost area for the genus. For future study, partial sequence data of mt-COI gene of the new species is docu mented.
Morphological information on mandible, forcipular segment, ultimate leg-bearing and postpedal segments of the holotype of Arrup ishiianus Uliana, Bonato & Minelli 2007 are supplemented to the original description. The newly provided information might be useful for species delimitation when similar species will be further discovered.
Two salticid species, Irura yueluensis (Peng & Yin 1991) and Synageles hilarulus (C. L. Koch
1846) are newly recorded from Japan. The genus Irura is also new to Japan, and I. yueluensis is the single Japanese species at the present. This genus can be distinguished from other salticid genera by having wide flat
body and male long fang.
The web of Phoroncidia altiventris (Araneae: Theridiidae), which had been unknown since its taxonomic description, was recently discovered and confirmed to form an orb-web structure. This result supports the thought that this species should be reassessed and placed in the family Araneidae.