Schematic of shell morphology and terminology of the Rhiostoma A apertural view with shell terminology and measurements of coiled-whorl height B breathing device types as recognised in this revision: knob, incomplete tube, notch, canal and tubular C inner peristomal lip variation as recognised in this revision: incision and hole.

 
 
  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