Fig. 1 Characters of external morphology. a Gnathochilarium, showing detail of mentum, Poecilocricus singularis, character 4 (1); b second body ring in ventral view, Poecilocricus singularis, character 7 (1). Seventh body ring in ventral view: c showing opening of gonopod without constriction, Erythrocricus sanguineostria- tus, character 10 (0); d showing opening of gonopod constricted, Argentocricus nobilis, character 10 (1). Poecilocricus singularis: e coxae of leg pair 5, character 14 (2); f coxae of leg pair 6, character 15 (2); g coxae of leg pair 7, character 16 (2); h telson in ventral view, showing shape of opening of paraproct, character 20 (0). cx coxae, hp hypoproct, m mentum, pr paraproct, stp stipes. Scale = 1 mm