Skolomystax, a new genus for the Australian species formerly included in Centroptilum Eaton (Ephemeroptera: Baetidae) Author Suter, P. J. Author Webb, J. M. Author Gattolliat, J. - L. text Memoirs of Museum Victoria 2023 Mem. Mus. Vic. 2023-12-31 82 1 48 http://dx.doi.org/10.24199/j.mmv.2023.82.01 journal article 10.24199/j.mmv.2023.82.01 1447-2554 8065508 Skolomystax collendus ( Harker, 1957 ) n.comb. Discussion. We have found no specimens that match the description of the male subimago or nymph described by Harker (1957) , and we have been unable to locate the type material. Harker (1957) stated type material was deposited in the British Museum, but it has no record of the types and this material was not deposited in the Australian Museum where Harker placed material from earlier papers. Therefore, we consider this species of uncertain status until collections are made at the type locality. The hindwing illustrated by Harker (1957: 75 , fig. 59) shows three unforked longitudinal veins with several crossveins between them and a sharply pointed costal projection that differentiates it from the other adults we have seen. The nymphal description is not sufficiently detailed to be of diagnostic value. It is possible S. collendus is conspecific with S. dyarrbi , as suggested by Webb and Suter (2011) , because both are known from the area around Sydney, NSW. Consistent with this is the presence of teeth on the inner margin of the outer incisors of the left mandible and a rugose base of the inner incisors, as illustrated by Harker (1957: 75) . In addition, S. dyarrbi has a short second segment of the maxillary palp and the basal segment is nearly as long as the galealacinia, as noted by Harker (1957: 76) for S. collendus . However, the illustration of the left mandible by Harker (1957) shows distinct teeth on the outer margin of the outer incisor, a characteristic we have not observed in any specimens of Skolomystax .