Chilton. — On new Isopods. 189 



Colour — dark brown, usually with a white median streak on the anterior 

 part of the thorax. 



Length, about •§• of an inch. 



Hab. Lyttelton Harbour. 



This species can be readily recognized by the peculiar character of the 

 terminal notch of the abdomen. This appears, however, to be subject to 

 some variation, for in one small specimen the median tooth was represented 

 only by a very small rounded projection, and in another of the ordinary size 

 the two lateral portions of the abdomen did not quite meet in the median line. 



Genus Jaera, Leach. 

 (Bate's and Westwood's Brit. Sessile-eyed Crust., ii., p. 314.) 



" Upper antenna very short. Lower antenna more than half the length 

 of the animal. Legs uniform slender. Pleon coalesced into one segment, 

 furnished with two minute subterminal uropoda. Pleopoda or branchial 

 appendages covered by a large plate occupying the entire under surface of 

 the pleon. Dactyla biunguiculate." 

 Jaera novce-zealandice, sp. nov. 



Body narrow elliptical, length about two and a half times the greatest 

 breadth. Head subrectangular, slightly more than twice as broad as long, 

 produced into a slight median lobe between the antennas. Eyes small, 

 situated near the middle of the lateral margins. Inner antenna reaching 

 to the third joint of the outer antenna, no flagellum distinguishable, basal 

 joint very much larger and broader than any of the others, second and fifth 

 joints equal and longer than the third and fourth, which are equal to one 

 another, sixth (terminal) joint small, setfe few and short. Peduncle of outer 

 antenna of five joints, first two equal and longer than the third, fourth and 

 fifth equal and longer than any of the others, flagellum a little longer than 

 the peduncle. Legs equal, all with propodos slender and longer than 

 carpus, dactylos short ending in three curved hooks. Segments of thorax 

 with short stout seta? on the lateral margins. Pleon nearly circular, lateral 

 margins with short setse, slightly emarginate at the base of the last pair of 

 pleopoda. These are lateral, being situated at some distance from one 

 another ; they are short, each consisting of a short peduncle bearing two 

 branches, inner one about as long as the peduncle and nearly twice as long 

 as the outer branch, both tipped with short setae. 



Length, about ^ of an inch. 



Hab. Lyttelton Harbour. 



This species resembles Janira and Asellus, and differs from Jaera in 

 having the two terminal pleopoda separated from one another and not 

 closely approximated in the centre as in Jaera ; in other respects, however, 

 it agrees well with Jaera. 



