“Recalls in form several of the Bornean species, but the apex is much depressed, the shell is not so pyramidal, and the whorls very conic.” (Sykes, 1902)
Sykes (1902) original descriptions on Opisthostoma laidlawi – “Shell ovate-conic, pale reddish horn-colour, apex obtuse; whorls 6-6 ½, strongly convex, the lower ones being regularly, but finely and somewhat distantly, marked with lamellae. The last whorl is solute, rounded, and bent backwards nearly to the suture of the fourth whorl.”
Opisthostoma laidlawi – “Alt. 2; diam. max. 2.5; diam. Min. 1.5 millim.” (Sykes, 1902)
Type locality – “Kelantan, Malay Peninsula” leg. J. Waterstradt (Sykes, 1902)
In Waterstradt (1902)'s itinerary, he visited one of the limestone hill at Kampung Pulai. The Pulai Princess cave (name in mandarin 紫霞洞 Zi Xian Tong) 4°47'38.18"N 101°56'31.45"E (http://pulai.org/cave.html) fits perfectly with Waterstradt's descriptions on the local population, temples and hill's topography (page 9-10). More importantly, he and his collectors sampled shell from here (Page 10). Thus, Pulai Princess cave is the type locality of Plectostoma laidlawi.
Waterstradt, J.1902 'Kelantan and my trip to Gunong Tahan', Journal of the Straits Branch of the Royal Asiatic Society 37, Pt. 4: 1-27.
other location: Kelantan, Malaysia.; Bukit Ciku 4, Felda Ciku, Gua Musang, Kelantan, Malaysia.