Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . Fig. 242. Menabites (AustralieHa) falloti (CoWignon, 1932). SAS-Z843. x 1. Differences between M. (A.) falloti and M. (A.) australis, described above,are to be found mainly in the longer retention of the trituberculate stage andin the depressed rectangular whorl section of the latter species in the earlystages. Although sufficient precise stratigraphic data are not available, it appearspossible to derive M. {A.) australis from M. {A.) falloti caenogenetically asdiscussed above. Specimen SAM-PCZ5870 differs from the re
Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . Fig. 242. Menabites (AustralieHa) falloti (CoWignon, 1932). SAS-Z843. x 1. Differences between M. (A.) falloti and M. (A.) australis, described above,are to be found mainly in the longer retention of the trituberculate stage andin the depressed rectangular whorl section of the latter species in the earlystages. Although sufficient precise stratigraphic data are not available, it appearspossible to derive M. {A.) australis from M. {A.) falloti caenogenetically asdiscussed above. Specimen SAM-PCZ5870 differs from the rest of the material in beingmuch larger and in having a much more compressed section on the inner whorls,though the latter may be partially due to secondary crushing. Ornament onthis specimen also weakens on the outer whorls, and may possibly connect CRETACEOUS FAUNAS FROM SOUTH AFRICA 319 ^r^5 t ^f. Fig. 243. Menabites (Australiella) falloti (CoWigaon, 1932). SAS-Z843. X 1. 320 ANNALS OF THE SOUTH AFRICAN MUSEUM with M. (Delawarella) gigas sp. nov., described below. SAM-PCZ5685 (Fig. 241) has inner whorls typical of M. {A.) fallotU butat a diameter of c. 180 mm, has an octagonal whorl section, very similar to thatof M. {A.) besairiei. It is easily distinguished from the latter, however, onaccount of the early appearance of the pentatuberculate stage. M. {A.) tintanti is a similar, large species, and was compared to M. {A.)falloti by Collignon (1970: 58); it differs mainly in retaining a quadrituberculatestage to a large diameter. SAS-Z2097 appears transitional to M. {A) tintantiin having a very weakly developed lateral tubercle throughout and robustribbing on the outer whorl. As discussed earlier, M. {A.) tintanti is intermediatebetween M. {A.) falloti and M. {A.) australis, and, given more material, mayprobably be synonymized with either of the two species. The inner whorls of M
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Keywords: ., bookcentury1800, bookdecade1890, booki, booksubjectnaturalhistory
