Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . ,0 22,0(34,9) 17 17 PCZ5694 112,0 41,0(36,6) 43,0(38,4) 0,95 44,0(39,3) 19 19 H199/8 140,0 44,0(31,4) 50,0(35,7) 0,88 59,0(42,1) 25 25 Z967 145,0 48,0(33,1) 48,0(33,1) 1,0 65,0(44,8) 22 22 Z870 185,0 53,0(28,6) 65,0(35,1) 0,82 74,0(44,3) 11x2 llx Description Coiling is evolute with an umbilical width of 35 to 45 per cent, increasingwith diameter. Whorl overlap is very little and the dorsal zone of impressionconsequently extremely shallow. The whorl section is rounded subtriangular,with greatest costal and intercostal
Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . ,0 22,0(34,9) 17 17 PCZ5694 112,0 41,0(36,6) 43,0(38,4) 0,95 44,0(39,3) 19 19 H199/8 140,0 44,0(31,4) 50,0(35,7) 0,88 59,0(42,1) 25 25 Z967 145,0 48,0(33,1) 48,0(33,1) 1,0 65,0(44,8) 22 22 Z870 185,0 53,0(28,6) 65,0(35,1) 0,82 74,0(44,3) 11x2 llx Description Coiling is evolute with an umbilical width of 35 to 45 per cent, increasingwith diameter. Whorl overlap is very little and the dorsal zone of impressionconsequently extremely shallow. The whorl section is rounded subtriangular,with greatest costal and intercostal width at the umbilical tubercle, which issituated somewhat ventral of the umbilical edge (Figs. 21B-C). Details of the early ontogeny are illustrated in SAS-36/3238 (Fig. 22)where the smooth stage continues up to a diameter of 5 mm. Following that,weak ribs with pinched, radially elongated umbilical tubercles appear, bifur-cating occasionally. Ventrolateral tubercles become visible in the umbilicalseam at a diameter of 20 mm. In this specimen ornament remains weak up to a. Fig. 21. Paratexanites umkwelanense (Crick, 1907). A. Partial suture of Whorl sections of SAS-36/3239 and SAS-Z967. All x 1. CRETACEOUS FAUNAS FROM SOUTH AFRICA 35 jwy%^
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Keywords: ., bookcentury1800, bookdecade1890, booki, booksubjectnaturalhistory
