. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. Reports on the Marine Mollusca in the South African Museum. 161 F. parviforata Sow. was described from Port Elizabeth : the Museum has it from Mossel Bay and Kalk Bay. I have received it from Ascension Island, and the specimens from St. Helena identified doubtfully by Smith * as gibberula Lam. ? belong to parviforata. Gen. Macheochisma Swainson. The single South African species belonging to this genus (which Swainson spelt as above) has usually been assigned to M. producta A. Ad., and though Sow
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. Reports on the Marine Mollusca in the South African Museum. 161 F. parviforata Sow. was described from Port Elizabeth : the Museum has it from Mossel Bay and Kalk Bay. I have received it from Ascension Island, and the specimens from St. Helena identified doubtfully by Smith * as gibberula Lam. ? belong to parviforata. Gen. Macheochisma Swainson. The single South African species belonging to this genus (which Swainson spelt as above) has usually been assigned to M. producta A. Ad., and though Sowerby identified different specimens at various times as producta A. Ad. and compressa A. Ad., I have but little hesi- tation in thinking that all belonged to a single form. I fail to see, however, why it was ever identified with the Australian forms, and proceed to describe it as Machrochisma africana n. sp. The shell is rather broadly rectangular, the length being a little more than twice the breadth, and the two ends are almost similarly rounded ; the slit is half the total length of the shell, narrowing rather gradually from the margin, which is noticeably depressed and strongly thickened at the broad end of the slit ; in colour it is rather vaguely blotched and streaked with red on a light ground ; the sculpture consists of fine, regular ridges radiating downwards from the slit to the margin all round, with somewhat irregular concentric growth-lines which produce bead- ing where they cross the ridges. Long. 22 mm. ; diam. max. 10 mm. Hab. Port Alfred (Becker). A r n £ ii Fig. 3.—Machrochisma africana n. sp. A young shell from the same J v locality measures 10 x 4-5, thus maintaining practically the same proportions. The Museum has specimens from Scottburgh (Burnup). It. * Lond., 1890, p. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustra
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