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. Bulletin of the British Museum (Natural History), Geology. 256 R. A. FORTEY & R. M. OWENS â¢v- : »*** ^ym i1". ? â ®r"1'" ». Fig. 110 Didymograptus (Didymograptus) spinulosus Perner 1895. a, early Llanvirn, D. artus Biozone, Llanfallteg Formation, loc. 55, whole rhabdosome, x 4, Q5163; b, Lower Llanvirn, cast of holotype, C. retroflexus Biozone, Sarka Formation, Osek, Bohemia, x 4, Nat. Mus. Prague NM-L 7564 (cast supplied by Dr R. Prokop); c, as last, latex cast of proximal end (showing probable isograptid development in obverse view, sicula incomplete), x 15, Nat. Mus
. Bulletin of the British Museum (Natural History), Geology. 256 R. A. FORTEY & R. M. OWENS â¢v- : »*** ^ym i1". ? â ®r"1'" ». Fig. 110 Didymograptus (Didymograptus) spinulosus Perner 1895. a, early Llanvirn, D. artus Biozone, Llanfallteg Formation, loc. 55, whole rhabdosome, x 4, Q5163; b, Lower Llanvirn, cast of holotype, C. retroflexus Biozone, Sarka Formation, Osek, Bohemia, x 4, Nat. Mus. Prague NM-L 7564 (cast supplied by Dr R. Prokop); c, as last, latex cast of proximal end (showing probable isograptid development in obverse view, sicula incomplete), x 15, Nat. Mus. Prague NM-L 7562, specimen figured by Boucek (1973: pi. 13, fig. 1). number is clearly an error for By8205âwhich is the specimen number for Skevington's figured slab. Fig. 111 shows the identical stipe expansion diagrams for one of the fully grown specimens from the Llanfallteg Formation and the holotype of D. pluto. However, the description also matches the type specimen of D. spinulosus Perner 1895 from the early Llanvirn Corymbograptus retroflexus Biozone of Bohemia; the stipe expansion diagrams completely overlap. Furthermore, Boucek (1973: pi. 13, fig. 1, lower left; Fig. 110c herein) has figured a specimen in relief which shows a good isograptid arch in obverse view, and another (ibid., fig. 4) which shows a narrow sicula. On the basis of comparison with these specimens we are obliged to refer the Llanfallteg material, and D. pluto, to the senior species D. spinulosus Perner, a form. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original British Museum (Natural History). London : BM(NH)
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