424 Dr. C. Cliilton on a new 



Antennae subequal ; peduncle of upper antenna as long as 

 the flagellura, reaching to the middle of the last joint of the 

 peduncle of the lower, which is slightly longer than its 

 flagellum. First gnathopoda with the carpus as long as the 

 propodos, its posterior margin bearing a regular row of about 

 fifteen long setae, which increase in length distally ; propodos 

 subrectangular, widening distally, palm nearly transverse, 

 well defined by a knob formed by a projection of the posterior 

 margin. Second gnathopoda with the ischium, meros, and 

 carpus all small, subequal, the carpus not produced into a 

 lobe ; the propodos very large, about as long as the basos, 

 rectangular, attachment to carpus narrow, both margins 

 straight and free from setae; palm nearly transverse, defined 

 as in the first gnathopod, slightly convex, bordered by one 

 or two irregular rows of short setse of varying lengths ; 

 dactylos stout, with a slight projection on the inner margin 

 near the base. Last three pairs of pereiopoda with the basos 

 very broad, its posterior margin very convex, minutely 

 serrate. Third uropoda very minute, peduncle indistinct, 

 apparently fused with its segment, the single ramus pear- 

 shaped and bearing a few minute setse. 



Female. Difi'ers from the male in the second gnathopoda, 

 which are like the first in shape and size, but have the carpus 

 shorter, subtriangular, with the row of setse more oblique and 

 containing only about five or six setse. 



Colour. Greyish or nearly white. 



Size. Largest specimens about |^ of an inch (5 millim.). 



Habitat. Mountain streams near Port Chalmers, up to 

 about 1500 feet above sea-level {Chilton). In hillside stream 

 at Rast Taieri ; from spongy moss at top of Mount Cargill, 

 2200 feet, and on Swampy Hill, 2400 feet (G. M. Thomson). 



Bemarks. This species appears to be very distinct and 

 easily distinguished from the other species of the same genus 

 of which I have descriptions at my command. The chief 

 distinguishing points seem to be : — 



(1) The body is stout and broad and the side-plates deep. 



(2) The lower antennae are only slightly longer than the 



upper ; usually they are much longer. 



(3) The gnathopoda are very characteristic, especially in 



the regular row of setae on the carpus of the first and 

 in the very large rectangular propodos of the second. 

 In neither is the carpus produced into a lobe lying 

 alongside the base of the propodos. 



(4) The third uropoda appear more rudimentary than in 



most of the species. 

 In addition to the description given above, I add the 



