ad Dr. R. O. Cunningham on the Zoology of 
with whose curious form I had long been familiar from figures. 
This animal occurs plentifully about Sandy Point, all Was 
taken in hundreds in our seine. When on the ground, it crawls 
along very sluggishly ; but I have seen it paddling rapidly on 
its back along the surface of shallow pools. The same day I 
found numerous fragments of a large spiny Lithodes, very 
closely resembling our L. arcticus, about which we had some 
correspondence a year or two ago. This and another species 
of the same genus, which is not nearly so spiny, the spines 
being replaced in great part by tubercles, appear to be two of 
the most abundant Crustacea in the eastern part of the Strait. 
In both, as in all the other foreign species of Lithodes which 
I have had an opportunity.of examining, the pleon is formed 
on the same plan as that of our British one; ¢. e. in the male 
the plates are symmetrical, while in the female they are pro- 
minently. asymmetrical. I got a small male specimen of what 
I think may be a third species, at Port Famme, one day we 
spent there. I procured several other Decapoda in the Strait, 
a small Munida [App., [V.] among the number, and a variet 
of sessile-eyed Crustacea, though not so many as I satire ited. 
I got one or two Nymphons and a species of Hyperia [App., V.]. 
We left the Strait about the middle of February for the Falk- 
land Islands, to get fresh supplies of provision and coal, and 
reached Stanley Harbour in the course of three days. While 
we were there, the weather was very broken, so that I could 
not accomplish any long excursions; but, as far as I could 
judge, there appears to be a very great similarity between the 
fauna and flora of the Falklands and those of the Strait. We 
left Stanley on the 2nd of March, and on the following day, 
in the forenoon, we noticed several brilliant scarlet-coloured 
patches in the water floating past the ship. We investigated 
their nature by means of a bucket let down over the side, 
and found they were composed of multitudes of a small ma- 
crurous decapod which swam rapidly about by rapid flexions — 
and extensions of the tail, the movement being backwards, as — 
in our common lobster. I preserved several specimens of the — 
animal, besides making a sketch of it [App., VI.; Pl. XXI. — 
fig.2|,which I send to you. The entire length of the crustacean, — 
when the tail, which was ordinarily curved underneath the 
body, was extended, was about three-fourths of an inch; and 
the limbs bearing the chele were nearly an inch long. The- 
general colour was scarlet, the eyes, a large patch on the — 
carapace, and a line extending along the abdominal segments — 
bluish black. I have not been able to identify the animal from the ~ 
descriptions I have with me. I ought, however, to state that — 
I have a very small stock of books at hand. Captain Mayne — 
‘| 
