Group 1. Radial sculpture predominant

Group 2. Spiral sculpture predominant, or radial and spiral sculpture about equally strong, or virtually no sculpture present

Group 1. Teleoconch whorl entirely detached

Group 2. Teleoconch whorls (almost) entirely attached. Supraperipheral usually cord present

Group 3. Teleoconch whorls (almost) entirely attached. Supraperipheral cord absent (check also D. tyloacron)

Group 1. Shell white

Group 2. Shell pale corneous, to yellowish green or brown

Group 1. Last whorl with 2 or more distinct spiral threads (rare specimens of P. tambunanensis and P. kusana have 1 spiral thread)

Group 2. Last whorl with 1 spiral thread, or without a spiral thread

Group 1. Protoconch with spaced spiral threads which are predominant over the radial sculpture

Group 2. Protoconch with fine spiral grooves, usually about as strong as the radial sculpture or weaker, or protoconch without spiral sculpture

Group 1a. Suture between the whorls coinciding with the periphery. Shell 13.5–24.5 mm wide in adult specimens

Geotrochus labuanensis-group (G. labuanensis, G. kinabaluensis, G. oedobasis)

Group 1b. Suture between the whorls coinciding with the periphery. Shell 10–12.5 mm wide in adult specimens (check also G. oedobasis)

Group 2. Suture slightly below the periphery in the last 4–5 whorls of adult specimens