Subgenus Thraulus Eaton, 1881

Diagnosis.

Identical to the generic diagnosis, except that gill I is always composed of one or two lanceolate and long lamellae.

Type species.

Thraulus bellus Eaton, 1881 by original designation.

Included species.

Thraulus (Thraulus) amravati Vasanth, Subramanian & Selvakumar, 2022 [southern India],

T. (T.) bellus Eaton, 1881 [Europe],

T. (T.) bishopi Peters & Tsui, 1972 [Peninsular Malaysia, Vietnam, southeastern China],

T. (T.) connubialis Grant, 2024 [east Malaysia Sabah],

T. (T.) cursus Grant, 2024 [Japan],

T. (T.) cuspidatus Vasanth, Subramanian & Selvakumar, 2022 [southern India],

T. (T.) demoulini Peters & Tsui, 1973 [Thailand],

Th. (Th.) eloisae sp. nov. [Papua New Guinea],

T. (T.) fatuus Kang & Yang, 1994 [Taiwan, Japan],

T. (T.) femoratus Li, Liu & Zhou, 2006 [southeastern China],

Th. (Th.) granti sp. nov. [Papua New Guinea],

T. (T.) ishiwatai Grant, 2024 [Japan Okinawa],

T. (T.) jacobusi Srinivasan, Sivaruban & Barathy, 2022 [southern India],

Th. (Th.) longinquus sp. nov. [Papua New Guinea],

T. (T.) macilentus Kang & Yang, 1994 [Taiwan, Japan],

T. (T.) madagasikarensis Grant, 2024 [Madagascar],

T. (T.) mudumalaiensis Soman, 1991 [southern India],

Th. (Th.) nabire sp. nov. [Indonesia, Papua],

T. (T.) nihonensis Grant, 2024 [Japan Okinawa],

Th. (Th.) noe sp. nov. [Papua New Guinea],

Th. (Th.) ogea sp. nov. [Papua New Guinea],

T. (T.) plumeus Selvakumar, Vasanth & Subramanian, 2022 [northern India],

Th. (Th.) timorensis sp. nov. [Indonesia, West Timor],

T. (T.) turbinatus (Ulmer, 1909) [Comoros],

T. (T.) umbrosus Kang & Yang, 1994 [Taiwan],

T. (T.) vellimalaiensis Vasanth, Subramanian & Selvakumar, 2022 [southern India],

Th. (Th.) wemale sp. nov. [Indonesia, Seram].

Distribution.

Mainly in the Oriental and Palaearctic regions, with only two species known from the Afrotropical area in the islands of Comoros and Madagascar; the subgenus seems absent from continental Africa south of the Sahara, as well as from Australia.