A Pterocyclos subalatus Sykes, 1903, holotype UMZC 1032 from Gunong Inas, Perak, Malay Peninsula B Pterocyclos spelaeotes (Tomlin, 1931), lectotype NMW 1955.158.01107 from Batu Cave, Kula Lumpur, Selangor C Pterocyclos umbraticus (Benthem Jutting, 1949), holotype ZMA 135622 from Maxwell’s Hill, Perak, Malaysia D Cyclotus boxalli syntype NHMUK 1894.5.23.1 from Kina Balu E Opisthoporus battambangensis holotype MNHN-IM-2000-35506 from Battambang, Cambodia F Opisthoporus grohi holotype MNHN-IM-2000-35507 from Dak Nong, Vietnam. Photograph: H Wood, NMW (B), M Caballer, A Lardeur and V Heros, MNHN (E, F).

 
 
  Part of: Tongkerd P, Tumpeesuwan S, Inkhavilay K, Prasankok P, Jeratthitikul E, Panha S, Sutcharit C (2023) Systematic revision of the snorkel snail genus Rhiostoma Benson, 1860 (Gastropoda, Caenogastropoda, Cyclophoridae) with descriptions of new species. ZooKeys 1142: 1-144. https://doi.org/10.3897/zookeys.1142.90097