Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . -145),another gigantic species from the Aptian of Australia, has much sharper, andmore distantly spaced ribbing on the body chamber. Tropaeum obesum sp. a more inflated whorl section and more distantly spaced ribs on the bodychamber. Genus Australiceras Whitehouse, 1926 (= Colombiaticeras Royo y Gomez, 1945)Type species Crioceras jacki Ethridge Jun., 1880 from the Aptian of eastern Australiaby original designation Whitehouse (1926: 208). Diagnosis Coiling ancyloceratid or aspinoceratid in early Aptian species,
Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . -145),another gigantic species from the Aptian of Australia, has much sharper, andmore distantly spaced ribbing on the body chamber. Tropaeum obesum sp. a more inflated whorl section and more distantly spaced ribs on the bodychamber. Genus Australiceras Whitehouse, 1926 (= Colombiaticeras Royo y Gomez, 1945)Type species Crioceras jacki Ethridge Jun., 1880 from the Aptian of eastern Australiaby original designation Whitehouse (1926: 208). Diagnosis Coiling ancyloceratid or aspinoceratid in early Aptian species, butcrioceratitid in later ones. Early whorls not always in one plane; ornamented bytrituberculate ribs separated by a variable number of intermediaries. Tuber-culation ceases at variable diameters in middle stages of growth and may ormay not reappear on the body chamber. Discussion Whitehouse originally introduced Australiceras for crioceratitid forms only,a view followed by Wright (1957: L211). Latterly, the genus has been taken to 286 ANNALS OF THE SOUTH AFRICAN MUSEUM. Fig. 46. Tropaeum sp. indet. SAS Z804 from locality 151, Zululand, Aptian IV. Large body chamber fragment with last septum preserved and filled with numerous specimens of Tono- hamites? caseyi sp. nov. Photograph by courtesy of Tony Harris (Salisbury), x c. 0,24. CRETACEOUS FAUNAS FROM SOUTH AFRICA 287 include the early Aptian representatives of the lineage with ancyloceratidcoiling. The extent and variability of the early Aptian representatives of thegenus in the English Lower Greensand was exhaustively reviewed by Casey(1960, 1961), as was the scope of the Australian late Aptian representatives byDay (1974). Unfortunately, however, little or no work has been done on theCentral European or Soviet material since the beginning of the century. Spath (1931: 656) advocated that the name Australiceras be abandoned infavour of Tropaeum, due to the difficulty encountered in deciding whether or nottuberculation was p
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