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Cyrtocapsella japonica (Nakaseko, 1963)

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Shell relatively large, spindle-shaped in general form, composed of three parts, with the apical horn, divided by three strictures into four joints or segments; apical horn short, conical, triangular in section; The first part ceohalis, globular, with the columellar at the internal hollow; its columellar very thin, rodlike, connected with the apical horn; its pores tiny, circular, few in number; its wall thinner than that of second part; the second part containing thorax and first abdomen, subconical, the widest diameter near the lower part, each segment nearly similar in length; its pores rather large, circular, similar in size and form, as broad as the bars, hexagonally distributed, deeply set into the wall, with the hexagonal frames, about 12 in number across the maximum diameter; the stricture between thorax and first abdomen distinct, horizontal, marked by the internal transverse septum; the stricture which lies between the first and second abdomen thicker than the other strictures, connected with the wall of the first abdomen of the similar nature as that of the wall, and with the large pore in the centre of the basal pole; the third part the second abdomen, anti-conical, the widest diameter at the base; its pores dissimilar in size and form, subcircular or subelliptical, fairly well spaced, irregularly arranged; its wall thinner than that of the second part, and with smooth surface; aperture small in diameter, with rough margin, with the spines, but not the teeth.
Length of apical horn, 18µ; of the thorax, 50µ; of the first abdomen, 70µ; of the second abdomen, 80µ; breadth of the widest diameter, 108µ; diameter of the pores of the second part, 6µ; of the pores of the third part, 2-8µ.
(Nakaseko) 1963











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