388 Prof. C. Clultou on a 



XLIV. — A new Freshwater Gammarid from Neio Zealand. 

 By Charles Chilton, M.A., D.Sc, JF.L.S., Professor of 

 Biology, Canterbury College, New Zealand. 



[Plate XL] 



''J'hrOUGH the kindness of Mr. J. Crosby Smith, of Invercargill, 

 I am able to describe a new Gammarid from the surface 

 freshwaters of New Zealand. He obtained it from a small 

 pool near the top of Mt. Anglem in Stewart Island at a 

 height of about 2800 feet above sea-level. Unfortunately 

 only one specimen was obtained ; however, this is quite 

 sufficient for me to identify the animal satisfactorily, and 

 as it is undoubtedly different from any Grammarid hitherto 

 described from the freshwaters of New Zealand, I venture to 

 describe it as a new species. It is evidently pretty closely 

 allied to the subterranean species Phreatoganimarus fragilis, 

 and I am referring it to that genus, though it differs from 

 the definition of the genus as given by Mr. Stebbing in 

 having the first gnathopod distinctly smaller than the second 

 and of distinctly different form, for in his generic diagnosis 

 Mr. Stebbing says " First and second gnatliopods equal " *. 

 His diagnosis was, however, drawn up from the single type 

 species, and where a genus is based on minute points of 

 difference as exhibited by a single species it is easy to restrict 

 the characters of a genus too narrowly. I give a brief 

 .specific diagnosis and a fuller description of some points in 

 the single specimen I have examined. 



Phreatoqammarus propinquus, sp. n. 

 '(PI. XI. figs. 1-6.) 



In general appearance, antennge, perasopoda, and uropoda 

 closely resembling P. fragilis, but differing in the gnathopoda. 

 First gnathopod smaller than second and of different form, 

 having carpus longer than propod, the latter widening distally 

 and with palm transverse. Second gnathopod with carpus 

 short, subtriangular ; propod twice as long as carpus, ovoid ; 

 palm very oblique. 



Colour " nearly white." 



Length of body 5 ram. 



Hah. Small pool near top of Mt. Anglem, 2800 ft. above 

 sea, Stewart Island, New Zealand. 



* ' Das Tierreich,' Amphipoda, I. Gammaridea, p. 453. 



