132 TECTIBRANCHIATA.—PLEUROBRANCHIDA. 
and the edges of the mantle being incurved on all 
sides around the foot—may have in some measure 
prevented the access of the water to the vital 
parts. At the end of that time I replaced it in 
sea-water, where it soon partially recovered its 
activity, relaxed its mantie, and contracted it 
dorsally so as to expose the groove between it and 
the foot, greatly protruding the tentacles and veil, 
and the branchial plume ; thus I was enabled to get 
a much better sight of these parts. As soon as it 
was replaced in the sea-water, a quantity of white 
mucus was discharged from the whole surface, 
most copiously from the foot, which as it lay on 
its back was uppermost. This mucus gradually, 
by the contractions of the animal, was accumulated 
in a knob at the posterior end of the foot, and then 
thrown off. The reticulate structure of the mantle 
integument was much more distinct than in health ; 
it was seen to form a delicate lacework of yellow 
fibres all over the surface, covering and enclosing 
a peliucid parenchyma. 
The animal evidently had been injured by its 
bath of fresh water; for it lay on its back, ex- 
panding and contracting its various parts, without 
the power of turning over to crawl, or even of 
adhering by the foot when turned, but rolling 
helplessly back. The form and appearance, too, 
were very different from those of health; the 
groove being widely exposed by the contraction of 
the mantle, in which state the animal resembled 
some published representations of it more closely 
than when in health. 
The student of nature, one who really delights 
to contemplate the wonderful works of God, as they 
appear in the conditions and under the circum- 
