Bathytoma viabrunnea

Bathytoma viabrunnea, common name the brown-banded turrid, is a species of sea snail, a marine gastropod mollusc in the family Borsoniidae.

The transverse sculpture in the earlier whorls (which are pure white) consists of rather crowded flutings depending transversely forward from the sutural margin for a third of the width of the (visible) whorl, which then swells outward, marked by strong growth lines, to a series of peripheral angular nodulations which mark the course of the anal fasciole.

The last three and a half whorls take on a warm brownish tint, the fasciole being a still darker and somewhat livid madder brown.

The columella is slightly twisted, swollen, white, smooth, attenuated in front, with no callus, as long as the canal.

The shell is closely allied to † Bathytoma cataphracta Brocchi 1814, of the Miocene of the Paris and Vienna Basins.

The several varieties even, so beautifully figured by Hoernes in his monograph of the Vienna Tertiary mollusks, are reproduced in the recent form.

The verge is very large, recurved, flattened cylindrical, bluntly pointed; gills two, the lamellae rather short, the organs themselves rather long and of a dark greenish color.

Bathytoma viabrunnea (specimen in MNHN, Paris)