. Bulletin of the British Museum (Natural History), Geology. ARENIG IN SOUTH WALES 215 Stapeleyella aff. abyfrons sp. nov. (Figs 80a, b) 1909 Trinucleus sp.; Thomas, in Strahan et al.\ 18. Material. Disarranged dorsal exoskeleton, and several cephalic fragments. Horizon and locality. Fennian, Pontyfenni Formation, ?B. rushtoni Biozone; cutting on A40, Castell-y-waun, west of Bancyfelin (loc. 21). Description. Glabella and genal lobes with fine reticulate sculpture, occipital ring without spine. Sixteen radii per half-arc. El9 E2 complete, very close together anteriorly, more widely separated p
. Bulletin of the British Museum (Natural History), Geology. ARENIG IN SOUTH WALES 215 Stapeleyella aff. abyfrons sp. nov. (Figs 80a, b) 1909 Trinucleus sp.; Thomas, in Strahan et al.\ 18. Material. Disarranged dorsal exoskeleton, and several cephalic fragments. Horizon and locality. Fennian, Pontyfenni Formation, ?B. rushtoni Biozone; cutting on A40, Castell-y-waun, west of Bancyfelin (loc. 21). Description. Glabella and genal lobes with fine reticulate sculpture, occipital ring without spine. Sixteen radii per half-arc. El9 E2 complete, very close together anteriorly, more widely separated posteriorly. A few interradii with el and e2 present towards anterior. In and Il5 like the E series, very close together anteriorly, and more widely separated posteriorly. Both appar- ently complete; I2 in fifteenth and possibly sixteenth radius. Remarks. The presence of interradii in the E series invites comparison with such species as Bergamia rhodesi Whittard, B. matura Whittard and B. inquilina (Whittard), although there are apparently fewer than in any of these species. Unlike those, there is an (apparently) complete It (note that Whittard 1955, 1966 used a different I series terminology from that used here) and some I2. The presence of incomplete Ex and E2, together with (apparently) complete In and I,, immediately invites comparison with Stapeleyella abyfrons, although there are fewer radii, larger pits and greater regularity, with only a few interradii in the E series and no paired In. Although there are virtually no characteristic Y-shaped interradial ridges, we on balance prefer to associate these specimens with Stapeleyella, for other fringe characters are more similar to contemporaneous members of this genus than they are to those of 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 Briti
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