Chilton. — The Fresh-ioater Amphipoda of Neio Zealand. 55 



the same time Mr. Laing also found the species in surface streams at Otautau, 

 in Southland, in company with the next species, P. cxndeus. The two 

 species were found together in two different streams in that locality, and 

 though very different in appearance, one being colourless — almost white — 

 and the other dark blue, they appeared to be living together under precisely 

 the same conditions. Mr. Laing thinks that probably the P. subterraneus 

 may have got into the surface streams from springs feeding the streams, 

 much in the same way as appears to have occurred at Castle Hill. 



Mr. 0. A. Sayce* has called attention to the occurrence of three blind 

 fresh-water Crustacea in the surface waters of Victoria, and has given many 

 interesting facts with regard to them and their surface allies. Other examples 

 of the same thing have been recorded from North America also. In the 

 present case we have P. subterraneus living side by side at Otautau with 

 P. cceruleus, to which it is so closely allied that we may consider it as a 

 subterranean modification of that species. 



Paraleptamphopus caeruleus (G. M. Thomson). 



Pherusa ccerulea, G. M. Thomson in N.Z. Journ. Sci., vol. ii, p. 576 (1885). 

 Parale-ptamphopus cceruleus, Hutton in Index Faunae N.Z., p. 259 (1904). 

 Paraleptamphopus cceruleus, Stebbing in " Das Tierreich Amphipoda," 

 p. 295 (1906). 



This species was originally described by Mr. Thomson from specimens 

 taken in a small stream at the top of the Old Man Eange, in Otago, at a 

 height of about 3,000 ft., and for many years afterwards no further specimens 

 were discovered. In 1904 Mr. Crosby Smith sent me one or two specimens 

 of Amphipoda from the bog-water at the top of Swampy Hill, near Dunedin. 

 These were not in a fit state for an exact determination, but appeared to 

 belong to this species. In the next year Mr. R. M. Laing brought me un- 

 doubted specimens from a stream at Otautau, in Otago, where it had been 

 found in surface streams along with P. subterraneus. Subsequently I found 

 a single specimen among Crustacea sent to me from Ruapuke Island by 

 Mr. T. Horan, and in 1907 I collected numerous specimens in pools and 

 streams near Drummond, in Southland, and afterwards in streams near 

 Invercargill. All of these specimens show the dark-blue colour described 

 by Mr. Thomson, and this colour does not fade even after the specimen 

 has been kept for a long time in spirit. 



As already stated, this species may be looked upon as the surface form 

 from which P. subterraneus has arisen. 



Paracalliope fluviatilis (G. M. Thomson). 



Calliope fluviatilis, G. M. Thomson in Trans. N.Z. Inst., vol. xi, p. 240, 

 pi. xc, figs. 4 a-c (1879). Paracalliope fluviatilis, Hutton in Index 

 Faunae N.Z., p. 259 (1904). Paracalliope fluviatilis, Chilton in P.Z.S. 

 London, 1906, p. 704 (1906). Paracalliope fluviatilis, Stebbing in " Das 

 Tierreich Amphipoda," p. 297. 



This species is extremely abundant in all the fresh-water streams of 

 New Zealand, and also in many of the ponds formed by them. I have 

 seldom failed to find it in such positions in the South Island, and, though 

 I have fewer specimens from the North Island, it doubtless occurs there 



* " On Three Blind Victorian Fresh-water Crustacea found in Svirfacs Water," Ann. 

 Nat. Hist., ser. 7, vol. viii, pp. 558-64. 



