FEESHWATEK CRUSTACEA OF TASMANIA. 



7:5 



Phkeatoictjs brevicatjdatus, sp. n. (PI. 12. fig. 5.) 



The head is shorter than the two following segments. 



The hody is markedly sculptured as in P. spinosus, but is not spinous, only a few 

 inconspicuous seta? being present on the dorsum. The segments of the pleon are rather 

 broader than usual. 



The second antenna? are not very long ; the whole of the peduncle and most of the 

 flagellum has a serrated margin (PI. 12. fig. 10). 



The telson has the form shown in PI. 12. fig. 6 ; the uropods do not project much beyond 

 the end of the telson and are poorly furnished with stout spines. 



The colour is straw-yellow. 



Length 15 mm. 



Occurrence. In the deeper littoral of the Great Lake, where the bottom is chiefly 

 composed of a fine yellowish mud. 



Order AMPHIPODA. 



Family Gamiaeib*. 



Genus Neoniphargus. 



Neoniphargus, Stebbing, Trans. Linn. Soc. Lond. ser. 2, vol. vii. (1899) p. 424. 

 Niphargus, Thomson, Proc. Roy. Soc. Tasmania, 1892 (1893), p. 67. 

 Unimelita, Sayce, Proc. Roy. Soc. Victoria, vol. xiii. (1901) p. 238. 



Diagnosis (see also PI. 13). — Body much compressed, without dorsal projections and 

 with few setae. Coxal plates wide and deep, the fifth very wide and emarginated. 



First antenna? longer than second, with a small secondary appendage of one or two 

 joints. 



Inner plate of first maxilla? very narrow, bearing apically two or three plumose seta? 

 (PI. 13. fig. 5). Outer plate of maxillipeds with stout spine-teeth (PL 13. fig. 8). 



Gnathopoda subequal ; hands small, quadrate, and subchelate, with no conspicuous 

 sexual differences. Pereiopods normal, the three posterior pairs with coxal joints much 

 expanded. The two anterior pairs of uropoda with rami subequal ; the third pair only 

 just projects beyond the others posteriorly and has the inner ramus very small and 

 scale-like tipped with a single seta, the outer ramus one-jointed or with an additional 

 rudimentary joint at tip. Telson cleft, but not entirely to the base. 



c?V os vi 



Neoniphargus yuli, sp. n. (PL 13. fig. 1.) 



Head not longer than first segment. Eyes large, crescent-shaped. 



First antenna? not half as long as body, the three segments of the peduncle subequal, 

 with a few bunches of seta? ; secondary appendage two-jointed, not distinctly longer than 

 first joint of flagellum (PL 13. fig. 2). 



Pereiopods armed with bunches of very stout seta? ; terminal joint not much elongated 

 (PL 13. fig. 10). 



The three pairs of uropods reach to approximately the same point posteriorly and do 



