. Bulletin of the British Museum (Natural History), Geology. 250 R. A. FORTEY & R. M. OWENS Selenopeltis buchi macrophthalma (Kloucek 1916) (Fig. 105) (For synonymy see Bruton 1968: 65. Also Bruton, in Bruton & Henry 1978: 895 896; pi. 1, figs 2, 3, 5, 7). Lectotype (selected Prantl & Pfibyl, 19494*, as 'holotype'). National Museum, Prague, L 843; figured Bruton (1968: pi. 11, fig. 13). Sarka Formation, Llanvirn, Bohemia. Occurrence in Wales. The earliest occurrence of S. buchi macrophthalma is in the late Arenig (Fennian, biozone of Bergamia rushtoni), type locality of the Pontyfe
. Bulletin of the British Museum (Natural History), Geology. 250 R. A. FORTEY & R. M. OWENS Selenopeltis buchi macrophthalma (Kloucek 1916) (Fig. 105) (For synonymy see Bruton 1968: 65. Also Bruton, in Bruton & Henry 1978: 895 896; pi. 1, figs 2, 3, 5, 7). Lectotype (selected Prantl & Pfibyl, 19494*, as 'holotype'). National Museum, Prague, L 843; figured Bruton (1968: pi. 11, fig. 13). Sarka Formation, Llanvirn, Bohemia. Occurrence in Wales. The earliest occurrence of S. buchi macrophthalma is in the late Arenig (Fennian, biozone of Bergamia rushtoni), type locality of the Pontyfenni Formation; it is also recorded from the latest Arenig (biozone of Dionide levigena) and the earliest Llanvirn (D. artus Biozone) of the Llanfallteg Formation, type section, and at Scolton. Whittard (1961b) records two Llanvirn occurrences in Dyfed, at Abergwili and St Clear's. Material. More or less complete exoskeletons: It. 19704, , NMW ; crani- dium and pygidium: ; also , b, NMW Discussion. As noted above, the difference between buchi buchi and buchi macrophthalma is a sculptural one, and most reliably determined on the pygidium. A series of specimens from the Pontyfenni Formation shows the fine granulation typical of the subspecies macrophthalma, and there is no difference between these specimens and one from the early Llanvirn. Whittard (19616) also drew attention to the more rapid backward curvature of the pygidial pleural ribs on buchi buchi compared with buchi macrophthalma; in effect the ribs on macrophthalma run out horizontally for a short distance before commencing their backward curve. Whether this subtle difference is consistent is difficult to say on the basis of a few specimens, but it does apply to the material we have collected (compare Fig. 104 with Fig. 105). Whittard reported macrophthalma from the Shelve Church Beds, which we would regard as probably equivalent in age to the Pontyfenni specimens. There may p
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