Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . The band is bisected by a continuousmedian groove, and the surface is covered by fine, longitudinal striae whichconverge slightly when traced in an apical direction from one suture to the some cases, concave transverse striae are present in the area enclosed by thesiphonal lobe, giving rise to a distinctive reticulate pattern (Schleppstreifen ofHolder 1955: 374), whilst the ventral band in some juveniles is ornamented by CRETACEOUS FAUNAS FROM SOUTH AFRICA 175 a curious chevron-like striation. The interpretati
Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . The band is bisected by a continuousmedian groove, and the surface is covered by fine, longitudinal striae whichconverge slightly when traced in an apical direction from one suture to the some cases, concave transverse striae are present in the area enclosed by thesiphonal lobe, giving rise to a distinctive reticulate pattern (Schleppstreifen ofHolder 1955: 374), whilst the ventral band in some juveniles is ornamented by CRETACEOUS FAUNAS FROM SOUTH AFRICA 175 a curious chevron-like striation. The interpretation of these structures is far fromclear; Jordan (1968) suggested that the ventral ridge represents the trace of amuscle system controlling a pre-septal gas and fluid-filled space, but it is difficultto reconcile this with the extension of the band throughout the length of thebody chamber. The striations of the siphonal band on the phragmocone aretypically interpreted as the site of muscle or ligament insertion associated with pITi. V •? fyf\ fc t I1 I J, - d r in *v t. Fig. 14. Saghalinites cala (Forbes). BMNH C78855, from the St Lucia Formation, Maastrich-tian I, at locality 132 near Charters Creek Rest Camp, Lake St Lucia, Zululand. A and Dshow details of ventral structures; B and F the internal suture. A-D, x 2; E-F, x 1 > 176 ANNALS OF THE SOUTH AFRICAN MUSEUM
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Keywords: ., bookcentury1800, bookdecade1890, booki, booksubjectnaturalhistory
