Victorian Fvesh-ivater Amphipoda. 237 



Uropoda. — The first reaches beyond the second, and almost to 

 the ^\\& of the third ; the peduncle is long, extending as far as 

 the end of the peduncle of the second, and its inner and outer 

 upper margins bear about four spines ; the rami are subequal, 

 much shorter than the peduncle, and their upper margins and 

 apices are very spinulose. The second pair has the peduncle 

 short and of equal length to the rami ; in other respects they are 

 subequal to the first. The third pair and the telson have already 

 been described. 



Gen. 2. — Unimelita, gen. nov. 



Body much compressed, without any dorsal projections. Coxal 

 plates wide and deep, first pair not conspicuously widening 

 distally, fourth the largest, and deeply emarginated posteriorly. 

 Segments of metasome deep. Cephalon without any distinct 

 rostrum, lateral corners obtusely rounded. Eyes rather large. 

 Upper antennae longer than the lower, with small secondary 

 appendage. 



Oral parts normal. Inner plate of first maxillae very narrow, 

 and apically bearing only about three plumose setae. Outer 

 plate of maxillipedes with stout spine-teetli INIandible palp 

 having the ultimate joint not longer than the penultimate one. 

 Gnathopoda subequal, hands small, subchelate, the second 

 scarcely larger than the first, with no conspicuous sexual special- 

 ization. Peraeopoda normal, the three posterior paii-s with the 

 basal joint laminarly expanded. Branchial lamellae simple. 

 Incubatory lamellae rather narrow. The two anterior pairs of 

 uropoda with rami, subequal, the last pair projecting beyond the 

 others, and having the inner ramus minute and scale-like, the 

 outer one spinulose,, and tei'minating in a rudimentary joint. 

 Telson cleft about half way to the base, end of lobes spinulose. 



Remarks. — This new genus is introduced to receive a new 

 species described below, as well as G. M. Thomson's Niphargus 

 montanus from Tasmanian fresh-waters, which I have been 

 enabled to carefully examine through Mr. Thomson kindly 

 sending me co-types. In his original description of it^, he 

 pointed out divergencies from that genus. The present genus 



1 hoc. cit., p. 26. 



