Phycosoma O. Pickard-Cambridge 1880

GenusPhycosomaO. Pickard-Cambridge, 1880 Type species. Phycosoma oecobioides O. Pickard-Cambridge, 1880 from New Zealand. Diagnosis. Phycosoma can be distinguished from other Hadrotarsinae genera by the following combination of characteristics: 1. male with high carapace (cylindrical in many species) and slightly raised cephalic region, 2. median apophysis large, with S-shaped sperm duct (except Phycosoma corrugum Gao & Li, 2014, Phycosoma ripa (Zhu, 1998), and Phycosoma turriceps (Schenkel, 1936)), 3. embolus with a wide base situated anterior position of tegulum, embolic spire small, 4. theridiid tegular apophysis and conductor small, situated anterior distal part of bulb, 5. posterior part of epigyne with a scape, copulatory opening posteriorly situated (except Phycosoma turriceps) (Gao and Li 2014; Liu et al. 2025). Distribution. Worldwide. Comments. Phycosoma stigmosum Yin, 2012 was originally described based on a male specimen from Hunan, China. The morphology of the palp shows that the embolus lacks a wide base, a characteristic feature of the genus Lasaeola Simon, 1881, especially of the castrata group (Liu et al. 2025). However, as the holotype of this species appears to be lost, we were unable to study its detailed morphology. Nevertheless, based on the available evidence, we transfer Phycosoma stigmosum to Lasaeola as a new combination: L. stigmosum (Yin, 2012), comb. nov. Yoshida reported two species from Japan, Pholcomma japonicum Yoshida, 1985 and Pho. amamiense Yoshida, 1985, and subsequently transferred both species to Dipoena Thorell, 1869 (Yoshida 1985, 1991). Paik (1996) described D. kayaensis Paik, 1996 from Korea. Yoshida and Ono (2000) considered D. kayaensis to be a junior synonym of D. japonica (now Phycosoma japonicum), and Marusik and Koponen (2000) regarded D. kayaensis as a junior synonym of D. amamiensis (now Phycosoma amamiense). Yoshida and Ono (2000) proposed that the distinction between the two species lies only in habitus length. Basen on morphological comparison, we found that the two species share a same sclerotized plate on the anterior dorsal opisthosoma of the male, the identical sperm duct configuration inside the tegulum, median apophysis, and embolic base, and congruent structures of the embolus and vulva (Yoshida 1985, 1989, 1991, 2002, 2003, 2009; Zhu 1992, 1998; Paik 1995, 1996; Kim and Kim 1997; Song et al. 1999; Marusik and Koponen 2000; Yoshida and Ono 2000; Fitzgerald and Sirvid 2004; Zhu and Zhang 2011; Yin et al. 2012; Kim 2021; Xie et al. 2021; Suzuki et al. 2023, 2025; Hino 2024; Suzuki and Hisasue 2024; Hidaka and Eto 2025). Accordingly, we consider Phycosoma amamiense (Yoshida, 1985), syn. nov. to be a junior synonym of Phycosoma japonicum (Yoshida, 1985).