. Bulletin of the British Museum (Natural History), Geology. ZULULAND AND NATAL 357 Description. The coiling is very involute, with a tiny, funnel-shaped umbiHcus (6-9% of diameter). The whorl section is a compressed oval, the whorl breadth to height ratio varying from 0-55 to 0-71, the greatest breadth being typically at or just below mid-flank. The umbilical shoulder slopes gently outwards, producing a funnel-shaped umbilical depression, the flanks being gently inflated, converging to a narrow rounded venter. The surface of the shell is ornamented by low, flat, radial folds which arise at th
. Bulletin of the British Museum (Natural History), Geology. ZULULAND AND NATAL 357 Description. The coiling is very involute, with a tiny, funnel-shaped umbiHcus (6-9% of diameter). The whorl section is a compressed oval, the whorl breadth to height ratio varying from 0-55 to 0-71, the greatest breadth being typically at or just below mid-flank. The umbilical shoulder slopes gently outwards, producing a funnel-shaped umbilical depression, the flanks being gently inflated, converging to a narrow rounded venter. The surface of the shell is ornamented by low, flat, radial folds which arise at the umbilical seam as mere striae, but strengthen across the lower flank, flexing faintly forwards as they do so, to flex faintly back at mid- flank and pass almost straight across the upper flank and venter. The internal mould is smooth, or bears only faint, low folds. The suture is moderately subdivided with triphylloid saddles (Figs 2-3). Discussion. Ornament and whorl section clearly place our specimens close to P. {Hypophylloceras) subalpinum ellipticum ; specimens figured as PI. 5, figs 3a-c and PI. 6, figs 2a-b have the identical weak fold-like ribs and elliptical whorl section clearly shown in Kossmat's figures and in material illustrated recently by Wiedmann (1964). Other specimens, more compressed than previously-described material referred to this species (whorl breadth to height ratio as low as 0-55) but otherwise identical, we also place within the range of subalpinum ellipticum. None of our specimens show the constrictions described by Kossmat, nor the fine striations developed on well-preserved material ( Wiedmann 1964 : pi. 15, fig. 3c). The dimensions of ellipticum overlap those of P. {H.) subalpinum subalpinum, and involution and sculpture are identical. These similarities led Stoliczka to refer his Indian material to P. (H.) subalpinum Kossmat, however, separated the Indian material on the basis of the elliptical whorl section with the greatest breadth
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