CHEMNITZIA. 427 
rather opake white. The mantle is even with the shell, 
scarcely showing a fold at the upper angle of the aperture. 
The rostrum is very slender, not cloven, but truncate at the 
end, and, as usual, on the march precedes the foot. The ten- 
tacula are rather long, slender, not particularly divergent, 
and have but narrow margins for the auriform folds; they 
are taper, bevelled, and terminate in prominent white tips; 
the eyes are not very close together at the internal bases. 
Foot short, narrowish, rarely extending when fully deployed 
much beyond the body volution, truncate in front or very 
little concave, with short auricles, and a little contracted 
below them, carrying on a simple upper lobe, at the junction 
of the foot with the body, a thin, pear-shaped, light corneous, 
obliquely striated operculum; the foot has a rather obtuse, 
though lanceolate, termination. 
T have reproduced this species, partly with the view of cor- 
recting some slight errors, but principally to place it in imme- 
diate view, for comparison with its tumid variety, and with 
the next species, the Chemnitzia indistincta, and its variety 
that has been named C. clathrata, all of which have been 
strangely jumbled together; but very large series of both 
species and their varieties have, I think, enabled me to unravel 
various misapprehensions. With respect to the shell of the 
present species, it has only one well-marked tumid variety, 
which, as regards the animal, differs in no respect from its 
chief, as the posterior volutions of both, in the shell, are of a 
dark lead-colour ; but the variety is invariably of larger size ; 
the whorls, though the same in number, are more tumid, and 
the body volution is more than half the whole length of the 
shell ; there is rarely on the body and next turn more than 
one well-pronounced row of crenz, and a tooth is always 
visible in the aperture. I have a fine series of more than 
twenty examples of the variety, and 100 of the type, all of 
which have been examined alive. 
It is difficult to say whether Montagu’s figure represents 
the shell with the flat or tumid volutions, but as far as the 
indifferent engraving will allow one to judge, I should guess 
it to be the tumid variety. I believe, however, all collectors 
