68 NOTES ON TASMANIAN CRUSTACEA, ETC. 



placed in this genus, though they are somewhat different in 

 appearance, and diverge somewhat from the generic character 

 ot Niphargus, as defined by Spence Bate. On the other hand, 

 neither is sufficiently distinct to justify the institution of a 

 new genus for its reception, especially as the classification of 

 the whole group is in want of revision. I accordingly place 

 these forms here, pointing out under each species the features 

 in which they differ from the generic character. 



20. Ni^jharyus mortoni* n. sp. (PI. iv., figs. 11 and 12 ; PI. v., 

 figs. 1-5 ) 



The specimens described here were first found by me in a 

 small stream above Franklin, on the Huon Eiver, at an. 

 elevation of 200 to 300 feet above tide-marks The stream at 

 the time of my visit was a minute runnel of water, which had 

 cut a subterranean channel in many parts, and only here and 

 there showed itself above ground. The little Crustacea were 

 somewhat difficult of capture. They were mostly found 

 creeping about under the little stones and bits of wood in the 

 stream ; but, as soon as their hiding-places were disturbed, 

 they abandoned themselves to the current, and were swept 

 at once into darkness. 



About the same time Mr. Laing, of Christchurch, N.Z., 

 obtained one specimen (handed to me by my friend, Mr. 

 Chilton) from the under side of a stone in a stream near The 

 Springs, Mt. Wellington, that is is at an elevation of some 

 2000fc. More recently I have received a considerable number 

 of specimens from Mr. Morton, who obtained them from the 

 same locality. These were found clinging to the undersides of 

 stones, pieces of wood, etc. There is some slight diversity 

 amongst the different specimens from Franklin and Mt. 

 Wellington, chiefly, however, in the relative number of hairs, 

 setae, etc., occurring on the different organs. Such variations 

 are probably only individual or sexual. 



The gnathopoda in this species, have not the propoda as 

 broad as is usual in the genus. This, however, is not a feature 

 of such importance as the fact that the telson is cleft into two 

 distinct divisions, while in Nipliargus it is a single telson, 

 though deeply cleft. This, along with various other characters, 

 induced me at first to place the species in the genus Melita, to 

 which it approximates in many respects. But the latter genus 

 is characterised infer alia by the great diversity of the gnatho- 

 poda in the two sexes, a feature which is quite wanting in the 

 present form. The following are the specific characters : — 



Body (PI. v., fig. 5) greatly compressed; Coxsb of four 



*In honour of Mr. Alex. Morton, F.L.S., Secretary of the^ Royal Society of 

 Tasmania. 



