Cyclocosmia Ausserer, 1871

Yu, Kun & Zhang, Zhi-Sheng, 2018, On three species of the trapdoor spider Genus Cyclocosmia from China (Araneae, Halonoproctidae), Zootaxa 4532 (2), pp. 248-256 : 249

Genus Cyclocosmia Ausserer, 1871

Diagnosis. Cyclocosmia can be distinguished from other halonoproctid genera by the combined presence of a truncated opisthosomal disc bearing ribs and grooves and an eye group arranged in two rows. The opisthosomal disc is also present in two genera of Idiopidae : Galeosoma from Africa and Idiosoma from Australia ( Rix et al. 2017), but Cyclocosmia can be easily distinguished from both by the grouped eye arrangement.

Description. See Gertsch & Platnick (1975) and Schwendinger (2005).

Distribution. China, Thailand, Vietnam, Laos, United States of America, Mexico.

Remarks. The identification of species of Cyclocosmia is difficult due to the homogeneous morphology. The diagnosis of each species must be integrated, using both the copulatory structures and somatic structures. Examination of type specimens or specimens from the type locality are highly valuable for delimiting species. Identification using limited material or rough comparisons can also lead to misidentification. For example, Gertsch & Platnick (1975) misidentified specimens from Ban Khok of Thailand as C. ricketti from Guadun, Fujian of China ( Schwendinger 2005). And the new species described here, C. subricketti sp. nov. found in Chongqing (between Sichuan and Hunan), shows that Chinese Cyclocosmia female specimens from Taishun of Zhejiang (Zhu, Zhang & Zhang 2007), Zhangjiajie of Hunan (Song, Zhu & Chen 1999) and Lushan of Sichuan ( Zhang, Li & Gao 2007), identified as C. ricketti need to be re-evaluated when more material of both sexes is available.