506 PROFESSOR CHARLES CHILTON ON THE 
acute, those of both the first and second perseopoda being acutely produced in front ; 
the eye is large, showing a little colour in the spirit specimens and probably having 
been red in the living animal, but it is not so large as in the Saldanha Bay specimen. 
The terminal joints of the perzeopoda are rather wide distally, as shown in STEBBING’S 
figure. . 
It seemed possible, therefore, that after all we might perhaps be dealing with two 
species: one P. antarctica, with side plates more or less acutely produced in front, the 
other P. tenuipes (including P. osborni and P. atollr), in which some of the side plates 
were rounded in front, although, as already shown, the differences did not appear to be 
constant. Considerable interest was therefore attached to the examination of the 
specimens from Ceylon referred by WaLKER to T'riteta antarctica, to see if they were 
really distinct from P. atolla. It was found that in some points they are a little 
nearer to P. antarctica than the type specimen of P. atollc is; thus, for example, the 
side plates of the first gnathopod are acutely produced in front as in P. antarctica; the 
side plates of the second gnathopod, however, are rounded below. ‘The side plates of 
the first and second perezeopoda cannot be very clearly made out, but they appear to 
be fairly acute in front, though projecting rather more posteriorly than shown in 
STEBBING’S figure. In other points, however, these Ceylon specimens were clearly the 
same as P. atolli, and the eye is large and shows little colour in the spirit specimens. 
Consequently, after considerable hesitation, I was forced to remain at the conclusion at 
which [ had previously arrived, that it is impossible to separate the various forms into 
two species. ‘The species has more recently been recorded from the east coast of Africa 
by Mr Waker under the name of P. atolli, and it was some confirmation of the 
conclusion I arrived at to find that specimens in the Museum from this locality, 
though recorded under the name P. atolli, were in the separate tube labelled by him 
P. antarctica. 
It seems clear that here, as in other cases, we have one widely distributed species, 
most abundant in Antarctic and sub-Antarctic seas, but extending far to the north 
both in the Indian seas and in the Pacific, and that, although it is impossible to 
find constant characters for the separation of it into two distinct species, there are 
slight local differences, some showing one combination of characters, others another 
combination. 
A small specimen of this species was among some undetermined Amphipoda, 
collected at South Georgia in 1882-83, that were submitted to me by the authorities of 
the Hamburg Museum. 
[After the whole discussion of this species as given above had been written, I found 
further specimens from South Orkneys in a bottle of “residues” received in May 1912 
from various collections made at Scotia Bay in 1908. Some of these specimens were 
larger than those from the South Orkneys mentioned above, the largest being about 
5 mm. long. In the largest specimens the eye was very large, and red in colour, as in 
the Saldanha Bay and other specimens already referred to; in smaller specimens the 
