Pvn H,i I'UitlS

tantalizing
LIMOPSIS. 163
not to see the enclosed treasure as a reward
for my patience. I was more fortunate, however, in
the specimens which I obtained the following year.
One of them came out during the night and displayed
itself. The foot was the only part visible outside. The
mantle appeared to have no tube, although
I saw dis-
tinctly through its open folds the gills regularly napping.
The alimentary and branchial orifice was in front. The
excretal orifice was at the broader end, where faecal
pellets were occasionally ejected. The Limopsis extended
the foot beyond the narrower end of the shell,
and after attaching the extremity to the side of the
glass vessel, and contracting the foot above, it drew
itself up to the further point, like warping a vessel to
the anchor when moored; it then again
the foot, using
gated disk or sole,
stretched out
on each occasion the whole of the elon-
in the same manner as a Planaria.
Repeating this operation, it contrived by slow degrees
to crawl up the side, and travelled four inches in two
hours, being
at the rate of a mile in little less than three
years and eight months. On reaching the top it spun
with its foot a very fine and almost transparent but tena-
cious thread, the end of which it fixed to the inside rim
of the vessel; and it remained for twelve hours thus
with the beaks of its shell downwards. When
suspended,
I emptied the bottle, and put in fresh water, the byssal
thread still continued fixed, and the Limopsis kept its
former place. It only loosed its hold after having a slight
degree of force used. In this respect the strength and
duration of the attachment differed from that by which
Sphcerium lacustre orKellia suborbicularis suspends itself.
The process, however, is the same in all cases, whether
it be the occasional secretion by the last-mentioned bi-
valves of a slight gossamer filament or the production