A new genus and species, Carinocryptus semenyukae, new genus, new species, is described from southern Vietnam, differing from other genera of the family, including the apparently most similar genus Circulocryptus Golovatch, 2016, primarily by the peculiar mid-dorsal rib on postcollum metaterga, the presence of a cerotegument crust on the collum, following metaterga and epiproct, and of bipartite, stout, non-circular gonopodal telopodites, in which a separate, anterior, solenophorous branch shows, just opposite a retrorse spiniform solenomere on the main, basal branch, an underdeveloped accessory seminal chamber and a long seminal duct ending up apically. These two genera form the new tribe Circulocryptini, tribus nova, characterised by a biramous gonopodal telopodite, in which the seminal groove runs along the basal, posterior branch to end up on a distinct, retrorse, spiniform solenomere, whereas the anterior branch is a solenophore supplied with both an accessory seminal chamber or its anlage and an accessory seminal duct lying or starting opposite the solenomere tip. A new species of Circulocryptus is described from Cambodia: C. kompantsevi, new species, distinguished from both other known congeners by the conspicuously swollen anterior half of the collum and certain minor details of the gonopodal structure, i.e., the shapes of the prefemoral process and basal branch. All three presently known species of Circulocryptus are keyed. Ophrydesmus anichkini Golovatch, 2015 is put on record for a second time, again from southern Vietnam where the species shows peculiar, likely population-level variations in body colouration. Descriptive notes and the first meaningful illustrations are presented for Ophrydesmus kedahensis (Wang & Tang, 1965), a species known from continental Western Malaysia and Singapore. Based on the male holotype, the assignment of O. kedahensis to Ophrydesmus is confirmed, and a group of congeners it joins through sharing inflated male femora 3 and evident sternal cones outlined.

A new genus and species, Carinocryptus semenyukae, new genus, new species, is described from southern Vietnam, differing from other genera of the family, including the apparently most similar genus CirculocryptusGolovatch, 2016, primarily by the peculiar mid-dorsal rib on postcollum metaterga, the presence of a cerotegument crust on the collum, following metaterga and epiproct, and of bipartite, stout, non-circular gonopodal telopodites, in which a separate, anterior, solenophorous branch shows, just opposite a retrorse spiniform solenomere on the main, basal branch, an underdeveloped accessory seminal chamber and a long seminal duct ending up apically. These two genera form the new tribe Circulocryptini, tribus nova, characterised by a biramous gonopodal telopodite, in which the seminal groove runs along the basal, posterior branch to end up on a distinct, retrorse, spiniform solenomere, whereas the anterior branch is a solenophore supplied with both an accessory seminal chamber or its anlage and an accessory seminal duct lying or starting opposite the solenomere tip. A new species of Circulocryptusis described from Cambodia: C. kompantsevi, new species, distinguished from both other known congeners by the conspicuously swollen anterior half of the collum and certain minor details of the gonopodal structure, i.e., the shapes of the prefemoral process and basal branch. All three presently known species of Circulocryptus are keyed. Ophrydesmus anichkini Golovatch, 2015 is put on record for a second time, again from southern Vietnam where the species shows peculiar, likely population-level variations in body colouration. Descriptive notes and the first meaningful illustrations are presented for Ophrydesmus kedahensis (Wang & Tang, 1965), a species known from continental Western Malaysia and Singapore. Based on the male holotype, the assignment of O. kedahensis to Ophrydesmus is confirmed, and a group of congeners it joins through sharing inflated male femora 3 and evident sternal cones outlined.

Opinions and declarations Rendered by the International Commission on Zoological Nomenclature

Opinions and declarations Rendered by the International Commission on Zoological Nomenclature