149 



ON A NEW AND PECULIAR FRESHWATER ISOPOD 

 FROM BLOUNT KOSCIUSKO. 



By Chas. Chilton, M.A., B.Sc. 

 [With Plates XXIII. - XXVI.] 



Towards the end of 1889 I received fi'om 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 oi'igin 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 

 ' "Ram's Head." The creek (or a least a branch of it) runs here 

 'through a, in damp weather, boggy flat, 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., jSTo. 1, p. 11. 



A— July, 189!. 



