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III. On a Freshwater ScUzopod from Tasmania. By George M. Thomson, F.L.S. 



Eead 2nd ?\"ovember, 1893. 



(Plates XXIV.-XXVI.) 



In a paper read before the Royal Society of Tasmania on November 14th, 1892, I have 

 given a brief account of the discovery of this interesting Crustacean, Anaspides tasmanke*, 

 and have described it as the type, not only of a new genus, but of a new family of 

 Schizopoda. In some respects, indeed, the structure of this animal is so unique 

 as to entitle it to even higher specific rank ; but in many of its characters it is found 

 to be allied, though somewhat remotely, to the Euphausiidce of Sars {Thysanopodidce 

 of Bronn's ' Thierreich ' ). Owing to long isolation it has undergone very profound 

 modification. 



I found this species in a pool near the summit of Mt. Wellington, Tasmania — that is, 

 at a height of over iOOO feet. The pool was in a small crevice only two or three feet 

 deep, but seemed to have somewhat extensive ramifications among the rocky masses of 

 which the upper part of the mountain is composed. The shrimps which came into the 

 more open part were mostly small ; the larger ones appeared to hide in the deeper 

 crevices of the j)Ool and would not come out while anyone was near. 



I obtained only a few specimens at the time of my visit (January, 1892), but Mr. L. 

 Rodway, of Hol^art, was kind enough to make an expedition to the top of the mountain 

 at my request on May 24th, and obtained a further supply from under the thick coat of 

 ice which then covered the pool. He secured them by setting a small baited muslin 

 net, but found the larger specimens very shy, as they tried to get the bait through the 

 meshes of the net without venturing inside. Still he was enabled to obtain both 

 males and females, the former of which were not included in my own collection. 

 Unfortunately, none of the specimens in my possession are well preserved, so that it 

 has been very diflicult to make out their anatomical structure, and impossible to arrive 

 at several important details. 



In the pools and swampy ground round the spot where these were taken, Mr. Rodway, 

 and subsequently Mr. Morton, F.L.S. , of Hobart, obtained specimens of a small 

 Amphipod which I have described in the paper referred to as Niphargus montanus. 

 This species, like Anaspides, is evidently a very old type, belonging, apparently, 

 to a genus hitherto described only from Europe and composed chiefly of underground 



* This form, was originally described by me under the name of Aaaspis, but as my friend the Rev. T. E. E. 

 Stebbing informs me that this name is pre-occupied, I have altered it to Anaspides, at his suggestion, so that 

 the name of the new order may not have to be changed. 



SECOND SERIES. — ZOOLOGY, VOL. VI. 38 



