AUSTRALIAN MALACOSTRACA. 275 



The female differs from the male in the smaller size of the 

 posterior gnathopoda, which have an undefined hairy palm, and 

 a very small dactylos. 



Port Jackson, 2 10 fathoms. 



Genus Ictlius, Dana. 



Body much compressed. Antenna? elongate, and having long 

 flagella ; the inferior pair longest. Gnathopoda not prehensile, 

 vergiforin and unguiculate. Posterior pair of pleopoda furcate. 

 [2).] 



477. Icilius Australis. Plate iv., fig. 4. A.M. 



Icilius Australis, Haswell, 1. c, p. 274, pi. xii., fig. 2. 

 Icilius pwnctatus, 1. c, p. 343, pi. xii., fig. 2. 



Pereion ovate, first two segments very short. Eyes red, very 

 prominent. Superior antenna? much smaller than the inferior 

 pair, nearly as long as the body, with a uni-articulate appendage ; 

 third joint of the peduncle shorter than the others ; flagellum 

 longer than the peduncle. Peduncle of inferior antenna? very 

 stout, as long as the superior pair. Maxillipedes unguiculate, 

 hairy, provided with squamiform plates. Gnathopoda subequal, 

 slender, unguiculate, provided with long hairs ; the carpus rather 

 longer than the propodos. Two first pairs of pereiopoda large 

 and prehensile in the male, the propodos being short and broad, 

 with a deeply excavated, spine-armed palm, and the dactylos 

 stout and long. Last pair of pereiopoda longer than the others. 

 Pifth pleopoda with the inner ramus larger than the outer. 

 Inner ramus of sixth pleopoda foliaceous, outer small, long- 

 ovate. Length about 3 lines. 



Port Jackson (dredged). 



An examination of a series of specimens has made it appear 

 probable that I. australis and /. punctatus are to be regarded as 

 varieties of one species. 



Tribe ISOPODA. 



Body dorso-ventrally compressed. The thoracic legs consisting 

 of an anterior series of three, and a posterior series of four pairs. 

 Segments of the abdomen short, and often more or less coalescent. 

 Terminal segment well-developed. Abdominal appendages of two 



