Description of larvae of Allomatus nannup Watts is presented including a detailed chaetotaxic analysis of the cephalic capsule, head appendages, legs, last abdominal segment and urogomphi. Larvae of A. nannup are compared with those of the closely related species, Batrachomatus daemeli (Sharp) from which it differs by: (1) the lack of additional setae on the parietale, (2) the primary seta CO7 inserted distally on the procoxa, (3) the absence of additional pores and (4) the proximal insertion of the primary pore ANg on antennomere 4, and (5) the presence of several additional spines on each segment of legs. Within the Matinae, both Batrachomatus and Allomatus are postulated to share a monophyletic origin by the presence a several additional primary setae on legs.