274 Transactions. 



Art. XXXII. — Description of a Species of Phreatoicus from the 

 Surface Waters of Xeiv Zealand. 



Bv Charles Chilton, M.A., D.Sc, F.L.S., Professor of Biology, 



Canterbury College, New Zealand. 

 [Read before the Philosophical Institute of Canterbury, 6th December, 1905.] 

 In my paper on the subterranean Crustacea of New Zealand 

 published in 1894 (Trans. Linn. Soc, vi), when discussing 

 various questions in connection with the three species of Phrea- 

 toicus known at that time, I said, " The questions suggested 

 mav perhaps be some day solved by the discovery of species 

 of Phreatoicus still living above ground in the mountain-streams 

 of the Southern Alps, places where very little search of the kind 

 required has hitherto been made" (I.e., p. 202). I am not sure 

 that the questions under consideration are very much nearer 

 solution now than they were then, and certainly no species 

 of Phreatoicus has yet been found among our Southern Alps ; 

 but in making the statement quoted I little anticipated that 

 within the next twelve years so many species would be found 

 in other places. 



At that time there was known only the one genus, with three 

 species — two found underground in New Zealand, and the third 

 on the Mount Kosciusko plateau, in Australia. Now, thanks 

 to the researches of Mr. G. M. Thomson, Professor Baldwin 

 Spencer, Mr. T. S. Hall, and particularly of Mr. 0. A. Sayce, 

 we are acquainted with five species of the genus Phreatoicus, 

 and with no less than three other closely allied genera, each with 

 one species. All these additional forms, however, were from 

 Australia and Tasmania, and up to 1902 no surface form had 

 been recorded from New Zealand. In that year, however, 

 Mr. (now Professor) H. B. Kirk brought me specimens of a 

 Phreatoicus found in a fresh-water lagoon in Ruapuke Island, 

 in Foveaux Strait. These were exhibited at a meeting of the 

 Philosophical Institute of Canterbury on the 26th November, 

 1902 (see Proc. N.Z. Inst., xxxv, p. 564), but no description has 

 as yet been published. In the present year (1905) specimens 

 of the same genus were found at Mosgiel, and afterwards at 

 Woodhaugh, both places being near Dunedin. These have 

 been very kindly handed over to me for examination by Mr. 

 G. M. Thomson. 



The occurrence of the species at Woodhaugh reminds us how 

 little we really know of the smaller animals even of places that 

 have been fairly well searched, for Mr. Thomson and myself, 

 and probably many others, have made many collections from 

 this locality without coming across the species in question, 

 although it is by no means a particularly small one, some of 



