The Thyropygus induratus subgroup of the T. allevatus group is revised. Three new species are described from Thailand:
T. dormiens n. sp., T. laterolobatus n. sp. and T. macrosiamensis n. sp. The following species are redescribed and re-elevated
from subspecies status under T. allevatus (Karsch, 1881): Thyropygus induratus Attems, 1936 (= T. punctatus Attems,
1938, new synonym), Thyropygus quietus Attems, 1938, Thyropygus resimus Attems, 1938, and Thyropygus uncinatus (Demange, 1961). Thyropygus siamensis Verhoeff, 1938 (= Thyropisthus ligulus Demange, 1961, new synonym), is re-described. A case of species with identical gonopods but very different body size (T. induratus and T. quietus) is discussed.