The erroneous citation of Gualtieri (a misprint for 88. f. Q.) was not
in the copy, and, as the figure represents the _D. trunculus_ in the
page opposite, I suspect was carelessly placed here by the printer, when
our author had inserted it in his revised proof. I suspect this error
often occurred, as for instance in _Tellina planata_ and _radiata_,
where Gualtieri's figure (added during revision) was attached to the
former instead of to the latter. "Margo interne crenulatus," and nearly
the entire account of the teeth, were emendations.