by William Swainson, Zoological Illustrations Series II… (1829)
“ A species not conspicuous for its beauty, but by no means of common occurrence: its close resemblance to the next has induced us to illustrate both by figures. C. fumigatus seldom exceeds the size here represented; it may at once be known from franciscanus (which is a much smaller shell,) by the spiral whorls being concave, instead of convex: this species occurs in the Indian Ocean. ”
