149 
ON A NEW AND PECULIAR FRESHWATER ISOPOD 
FROM MOUNT KOSCIUSKO. 
By Ciias. Chilton, M.A., B.Sc. 
[With Plates XXIII. -XXVI.] 
Towards the end of 1889 I received from the Trustees of the 
Australian Museum, Sydney, a small collection of Australian 
Crustacea, containing among others, some terrestrial and fresh- 
water species collected by Mr. R. Helms while on an expedition 
to Mount Kosciusko on behalf of the Museum.* Among these I 
at once saw that one was quite different from any of the terrestrial 
and fresh-water Crustacea previously described from Australia, 
and that it belonged to a genus Phreatoicus established by myself 
in 1882, for a peculiar blind subterranean Isopod found in wells 
in Canterbury, New Zealand. This genus was of special interest 
both because of the situation in which the original species was 
found, and because it combined characters belonging to several 
different families, and was also, to some extent, intermediate 
between the Isopoda and the Amphipoda The discovery of a 
species belonging to the same genus in such a widely remote situ- 
ation as Mount Kosciusko, and living under such different con- 
ditions is therefore of peculiar interest, and will probably have an 
important bearing on the difficult question of the origin of the 
blind subterranean forms. In the present paper, however, I do 
not propose to enter upon this question, as I hope to be able to 
do that on a future occasion when describing more fully the sub- 
terranean forms from New Zealand. For the present I shall 
content myself with describing the new species as fully as possible 
and with discussing the position of the genus among the Isopoda. 
It will be well, however, first to give the circumstances under 
which the species was taken, as they are given by the finder, Mr. 
R. Helms, a collector of whose zeal and accuracy I had had experi- 
ence before he left New Zealand. 
The specimens were, he says, taken at a place ‘ locally known 
£ as “ Piper’s Creek,” at an elevation of 5,700 feet or perhaps 
‘rather more, on the track from “Pretty Point” towards the 
6 “Ram’s Head.” The creek (or a least a branch of it) runs here 
‘through a, in damp weather, boggy fiat, and at the time (early 
‘in March 1889) was slowly trickling along forming puddles here 
‘ and there. In one of these puddles where there was only a little 
# A short account of this expedition is given by Mr. Helms in the 
“Records of the Australian Museum,” Vol, I., No. 1, p. 11. 
A — July, 1891. 
