Go to National Library of New Zealand Te Puna Mātauranga o Aotearoa
Volume 68, 1938-39
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Notocallista (Fossacallista) opima n.sp. Plate 13, figs. 13–15.

Shell small, greatly inflated, beaks broad and prominent. Surface shining, with a few irregular grooves persisting across it from the distal parts, where they are well spaced and fairly regular. Hinge-plate narrow, left posterior lateral bounded dorsally by a groove. Left anterior lateral relatively slender, sharply pointed.

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Right anterior lateral pit small, median cardinal low down on the hinge. Ligament deeply sunk. Pedal retractor confluent. Pallial sinus ascending, very wide, tapering rapidly, broadly rounded at the end.

Holotype in Melbourne National Museum Collection.

Length, 13.3 mm.; height, 11.2 mm.; inflation (1 valve), 4.4 mm.

Oligocene-Miocene: Balcombe Bay, Victoria (Balcombian).

N. opima is easily distinguished from eburnea by its much greater inflation, more oval outline and broader, more prominent beaks. The sculpture is not so obsolete as that of eburnea and the lunule is relatively shorter and broader. Internally the species agree well, so they must be closely related.

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