. Bulletin of the British Museum (Natural History), Geology. . Fig. 27 Bohemopyge scutatrix (Salter 1859). Middle Arenig, Whitlandian (G. gibbsii Biozone), Penmaen Dewi Formation, slate quarry at Pwlluog, north of Whitesand Bay, St David's, Dyfed. a, external mould of imperfect dorsal exoskeleton, showing median suture and slightly truncate glabella, original of Salter 1867: pi. 25*, fig. 1 (as Ogygia peltata), x 2, SM A16729; b, glabella and part of thoracic axis, x 1, SM A33438. (allegedly female and male), recognizing the variability in this character. The largest specimens have axial width
. Bulletin of the British Museum (Natural History), Geology. . Fig. 27 Bohemopyge scutatrix (Salter 1859). Middle Arenig, Whitlandian (G. gibbsii Biozone), Penmaen Dewi Formation, slate quarry at Pwlluog, north of Whitesand Bay, St David's, Dyfed. a, external mould of imperfect dorsal exoskeleton, showing median suture and slightly truncate glabella, original of Salter 1867: pi. 25*, fig. 1 (as Ogygia peltata), x 2, SM A16729; b, glabella and part of thoracic axis, x 1, SM A33438. (allegedly female and male), recognizing the variability in this character. The largest specimens have axial width more closely approaching pleural width. Deep pleural furrows almost bisect the pleurae and run nearly to their tips. Tips of pleurae of anterior segment are bluntly rounded; posterior segments acquire short but distinct spines. Pygidium when undistorted always has a distinctly triangular outline, but a little transverse extension will destroy this (Fig. 28a). Pygidial length/width ratios fall in the range 0-51 to 0-75 for less distorted material; the smallest ratio belongs to the largest specimen. The narrow axis always occupies less than one-third, and on some specimens less than one-quarter anterior pygidial width, and continues gentle backwards thoracic taper to rounded tip at 08 of pygidial length. Eight axial rings are discernible, occasionally a faint ninth, and the less flattened material shows that the terminal piece was distinctly elevated above the border. Eight pairs of pleural furrows, with a short ninth pair adjacent to the terminal piece, deep and narrow and running to border. Interpleural furrows are much weaker, and correspond to the outer parts of the pleural furrows only; on some flattened specimens they may be almost obliterated. Trans- verse extension (Fig. 28a) tends to overdeepen them. Border not sharply defined, especially laterally, and may have been gently sloping behind the axis rather than horizontal. Doublure of slightly less width than that of pygi
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