CHEMNITZIA. 43] 
discovery of the species I neglected to enlarge them; I have 
now repaired the omission, by presenting above more correct 
diagnoses. Believing our shell to be the true Turbo Sand- 
vicensis, I of course adopt, as a matter of right and justice, 
Mr, Walker’s specific appellation. I think no other shell will 
ever be found to represent Mr. Walker’s object. 
Since the above was written, we have had the good fortune 
to capture several lively animals. 
Animal inhabiting a white spirally striated subglobose shell 
of four volutions, with a reflexed apex and strong fold on the 
pular. The colour throughout is hyaline pale azure. Mantle 
even with the apertural margin, except a slight canaliculation 
at the upper angle of the right side. The rostrum, which 
some call the mentum, is of the exact characteristic essential 
shape of the tribe ; m quietude it scarcely extends to the ante- 
rior margin of the foot, but on the march it considerably pre- 
cedes that organ. The tentacula are proportionately longer 
than in its congeners, not so triangular, nor furnished with 
such broad lateral membranes, nor do they coalesce so de- 
cidedly as in some species to form a veil; nevertheless they 
are bevelled and subtriangular, with the eyes at the internal 
bases. The tip of each tentaculum has a point of flake-white, 
giving, I think, only the appearance of a slight inflation ; or it 
may be real for a limited period, caused by the contraction of 
the muscle of the tentaculum. 
The foot is a singular deviation from that organ in the 
typical species; it is short, broad and blunt, truncate ante- 
riorly, there often twisting itself into acute angles, which, 
when they happen to fall in a line with the true tentacula, 
give the appearance of a pair on each side, but a change of 
position instantly makes that appearance disappear ; the ante- 
rior third portion of the foot is somewhat contracted ; at this 
point a transverse groove appears, from the centre of which 
another longitudinal one proceeds to the posterior end, dividing 
the foot below the transverse portion into two suboval lobes, 
each rounded at its termination and separated by an emargi- 
nation: whether these grooves are only depressions or solu- 
tions of continuity, I could not in so minute a creature satis- 
