Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . compressedwhorl section than the Zululand species. Bevahites sp. A gr. ex. B. subquadratus Collignon, 1948Fig. 215 Material NMB-D1185A and D1185B from an unknown locality in the Morrisvalearea, probably the authors (Kennedy & Klinger 1975) locality 147 of SantonianAge. Description The two specimens differ considerably in terms of strength of ornament,but are both characterized by a compressed whorl section with maximumwhorl breadth at the lateral tubercle. NMB-D1185A (Fig. 215A) has smooth inner whorls up to a diamete
Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . compressedwhorl section than the Zululand species. Bevahites sp. A gr. ex. B. subquadratus Collignon, 1948Fig. 215 Material NMB-D1185A and D1185B from an unknown locality in the Morrisvalearea, probably the authors (Kennedy & Klinger 1975) locality 147 of SantonianAge. Description The two specimens differ considerably in terms of strength of ornament,but are both characterized by a compressed whorl section with maximumwhorl breadth at the lateral tubercle. NMB-D1185A (Fig. 215A) has smooth inner whorls up to a diameter ofc. 15 mm. At a diameter of c. 30 mm virtually complete Bevahites ornament ispresent, though very weak, but the submarginal (3) tubercle appears absent atthat stage. With increasing diameter, however, the ornament becomes stronger,especially the lateral (2) and external (5) tubercles. NMB-D1185B (Fig. 215B-D), on the other hand, already has a distinctlateral ornament at 15 mm diameter, consisting of an umbilical (1) tubercle, CRETACEOUS FAUNAS FROM SOUTH AFRICA 279. Fig. 215. Bevahites sp. A. gr. ex. B. subquadratus Collignon, 1948. A. NMB-D1185B. X 1. 280 ANNALS OF THE SOUTH AFRICAN MUSEUM connected by a stout rib to a prominent ventrolateral spine leaning against theumbilical wall. At 30 mm diameter the total ornament is visible, showing thetypical joined submarginal (3) and marginal (4) tubercles and proliferation ofthe external (5) tubercles. The lateral (2) tubercle has apparently just appearedat this diameter, and is still weakly developed. Ornament strengthens withincreasing diameter, and at a diameter of 50 mm the submarginal (3) andmarginal (4) tubercles are completely separated. Ornament at this stage consistsof radially elongated umbilical (1), very strong lateral (2), weak clavate sub-marginal (3) and marginal (4), and strong clavate external (5) tubercles. Unfortunately the outer whorl of NMB-D1185B is crushed and eroded,but it shows the adult or
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Keywords: ., bookcentury1800, bookdecade1890, booki, booksubjectnaturalhistory
