Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . .^/. B Fig. 253. Menabites (Delawarella) sp. aff. jeanneti Collignon, 1948. SAM~PCZ5691. X 0,85. CRETACEOUS FAUNAS FROM SOUTH AFRICA 333 elongated and point strongly inward. With increasing diameter ribbing remainsweak and prorsiradiate with barely perceptible lateral (2) and submarginal (3),and slightly stronger marginal (4), but progressively stronger umbilical (1) andexternal (5) tubercles. Numerous intercalations and bifurcations occur, generallyat the site of the submarginal tubercle, but also occasionally a
Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . .^/. B Fig. 253. Menabites (Delawarella) sp. aff. jeanneti Collignon, 1948. SAM~PCZ5691. X 0,85. CRETACEOUS FAUNAS FROM SOUTH AFRICA 333 elongated and point strongly inward. With increasing diameter ribbing remainsweak and prorsiradiate with barely perceptible lateral (2) and submarginal (3),and slightly stronger marginal (4), but progressively stronger umbilical (1) andexternal (5) tubercles. Numerous intercalations and bifurcations occur, generallyat the site of the submarginal tubercle, but also occasionally at the umbilicaltubercle. This results in there being about twice as many external as internaltubercles. Specimen SAM-PCZ5691 (Figs 252-253) has part of the early bodychamber preserved. Here tuberculation weakens even more, and the ribsbecome wider spaced. The suture is only partially exposed in the present material. The keel, asfar as can be seen, is never very prominent.
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Keywords: ., bookcentury1800, bookdecade1890, booki, booksubjectnaturalhistory
