II HOBART AND THE MIDLANDS 69 



was not until Mr. Rodway pointed it out to a 

 New Zealand naturalist, Mr. Thomson, in 1893, 

 that anything was known of it in the scientific 

 world. It is now recognized as one of those 

 survivals of a bygone age of which the Australian 

 continent has furnished so many and such interest- 

 ing examples. The nearest allies of this animal 

 appear to be some marine shrimps which have 

 come down to us as fairly common fossils in the 

 sand deposited round the Permian and Carboni- 

 ferous seas of Europe and North America ; sub- 

 sequent to this very remote period they do not 

 seem to have existed in the seas, at any rate of 

 the northern hemisphere, so that an enormous 

 passage of the earth's history has occurred between 

 their peopling the northern seas and their survival 

 solely on the mountain tops of Tasmania. And 

 yet to judge by external appearance there is very 

 little difference in organization between the primi- 

 tive forms of the Carboniferous period and the 

 present-day Anaspides tasmaniae (Fig. 18). 



The Tasmanian Mountain Shrimp is sometimes 

 as much as two inches in length, of a dark brown 

 colour, and walks about on the stones and among 

 the weeds at the bottom of the pools, in the position 

 shown in the figure, browsing on the mosses and 

 Liver- worts and any small creatures it can catch ; 

 it very rarely swims, but when frightened it darts 

 forwards by flicking its tail and takes cover under 

 a stone. It differs from the ordinary Sea-shrimp 

 or Prawn in having all the segments of the front 



