V A GLIMPSE INTO THE PAST 145 



landulosum) and the deciduous Beech (J^. Gunnii), 

 which are unknown on the mainland. Many 

 characters of the invertebrate fauna are also note- 

 worthy. The freshwater Crustacea, for instance, 

 are represented by numerous peculiar forms such 

 as the two Mountain Shrimps, Anaspides and 

 Paranaspides, the species of Phreatoicus and Neoni- 

 phargus, which certainly cannot be looked upon 

 as the impoverished remnants of the Australian 

 continental types. All these facts are, of course, 

 quite consistent with the view that Tasmania was 

 on the high road of migration from the Antarctic 

 country whence these forms finally reached the 

 mainland. 



Tasmania itself, regarded from the zoogeograph- 

 ical point of view, is not a single homogeneous unit. 

 Although a very extended research into the dis- 

 tributional limits of the various animals and plants 

 would be necessary before a definite scheme could 

 be worked out, it seems that there are three chief 

 areas characterized by special forms. There is, 

 first of all, the central greenstone plateau with 

 its outliers on Ben Lomond and the broken and 

 greatly sunken south-eastern coast. This area is 

 characterized by the Eucalpyts and the common 

 Alpine forms of plants, which again crop out in 

 the highlands of southern Gippsland and western 

 Victoria, themselves perhaps geologically continua- 

 tions of the diabasic plateau. To this region 

 belong the Mountain Shrimps and the members 

 of the genus Phreatoicus, while it is also sharply 



SMITH; N.T. -^ 



