“Cyamiomactra problematica, Bernard, 1897. Plate 52, figs. 10, a, b.
Shell small, inequilateral to subequilateral, of very variable outline, thin and fragile, smooth, deep orange and white. Beaks contiguous, with the prodissoconch large, convex, and shining, slightly elevated. Anterior end attenuated, the dorsal margin sloping and straight, narrowly arched towards the slightly convex basal margin; posterior end higher, subtruncated or broadly rounded, the dorsal margin horizontal, very slightly descending. There is no sculpture, except very fine concentric growth-lines. Epidermis smooth, lightly shining. Colour bright orange from the beaks down over the posterior part of the valves, anteriorly white. Interior of the same colour as the outside, polished. Margins smooth, sharp. Hinge straight, with all the characters described for the genus. Resilifer very oblique. Pallial line simple not interrupted.
Length, 4.5 mm.; height, 3 mm.; diameter, 1.8 mm.
Type in the Mus. Hist. Nat., Paris.
Hab. – Stewart Island, in 35 fathoms, type (Filhol); Foveaux Straight, in 15 fathoms (A. Hamilton); Bounty Islands, in 50 fathoms (Captain Bollons); twenty-one miles and a half north-east of Wreck Reef, in 50 fathoms; twenty-four miles south-east of Long Point, in 120 fathoms (E.R. Waite).”
(Suter, 1913)
