Article: Trilobites from the Sholeshook Limestone (Ashgill) of South Wales

Eight trilobite species based on type material from the Sholeshook Limestone are redescribed and two new species erected. For the first time a topotype pygidium is illustrated for Stenopareia bowmanni (Salter). Tretaspis moeldenensis Cave is retained as a distinct species; a topotype pygidium of this form is also figured for the first time and histograms given of selected fringe characters. The previously undescribed pygidium of Lehua? princeps (Reed), is very similar to that of the type species L. vincula (Barrande) and supports the assignment of the species to Lehua made previously on the basis of cranidia only. Topotype material of Pseudosphaerexochus (Pseudosphaerexochus) juvenis (Salter) is distinguished from P. (P.) octolobatus (M'Coy) and a pygidium tentatively referred to the species. It is not evident that the two syntypes of Sphaerexochusl hoops Salter are specimens of the same species; that from Sholeshook is not a sufficient basis for the recognition of a distinct species. Flexicalymene cavei sp. nov. and Kloucekia extensa sp. nov. are distinguished from other Ashgill species of those genera. Lectotypes are selected for K. robertsi (Reed) and 'Acidaspis' turnbulli Reed. The latter species is tentatively referred to Diacanthaspis; it shows great similarity to D. decacantha (Angelin) of which it may ultimately prove a junior synonym.