It was not thicker than the thinnest wafer.

The back was marked with curved lines, exactly in the manner I have represented.

It shrank instantly when touched.

The two last joints of the long legs were furnished with thorn-like spikes.
Length of tail 0.37 inches.
of the body 0.2 inches.
of the thorax and head 0.3 inches.
of the entire animal 1.4 inches.
Breadth of body 0.62 inches.
Ditto of thorax 0.51 inches.
Length of third leg 1.9 inches.
Length of second leg 1.7 inches.
Length of hindermost leg 0.6 inches.
Length of eyes, peduncles 0.4 inches.
We caught a second animal of exactly the same size as the one figured, but apparently much more perfect.

Each of its tentacula terminates in a small feathering tip when it is in the water, like the little figures at the side, and by the help of which they swim; these have a horny feel to the touch, are destitute of smell, and look like a transparent scale when they lie in your hand.
We also caught this day some little transparent shells (Cuvieria) of a cylindrical form, and blunt at the end; they put out two little fins with which they swam.
I was unfortunately too unwell this day to describe all the other specimens we caught, which were numerous.