THE TASMANIAN NATURALIST 
9 
ally, according to the kind of pond or lake it lived in — those kinds that 
inhabit small ponds, frequently liable to dry up, producing ‘resting’ eggs 
at more frequent intervals than those inhabiting large lakes. But to go 
fuller into that question would lead us into very deep waters, so deep 
that no Crustacea would be found in them but only abstract ideas and 
metaphysical speculations. 
Mr. Smith has since sent us an account of his work in Tasmania 
which appeared in the proceedings of the Royal Society, from which 
Figs, i and 3 are taken ; and also the following concerning Paranaspides 
lacustris : This type of a new genus of the Anaspididae was found by 
me in the Great Lake, on 
the central plateau of Tas¬ 
mania, at an elevation of 
3,700 feet. It inhabits the 
littoral zone of the lake, 
living among the rocks and 
water weeds, rather after 
the manner of a prawn. 
It is totally different in 
external appearance to An- 
aspides, being of a green 
transparent colour sparcely 
powdered with black dots, and the body exhibits a marked dorsal flexure 
very much as in Mysis, to which it bears an extraordinary superficial 
resemblance. The largest specimen obtained was about an inch in 
length. It pursues a swimming habit, with which is correlated the 
flexure of the body, the elongation of the abdomen, the enlarged tail fan, 
and the enlarged scales on the second antenna? The extremely abun¬ 
dant developement of this Crustacean fauna in the littoral zone of the 
Great Lake was very striking, and it seems probable that it furnishes an 
important part of the food for the imported English brown trout, which 
in this lake may attain to the enormous weight of 25 lbs. A dissection 
of the stomachs of several trout revealed the fact that they had been 
feeding upon these creatures. The Anaspidacea and Phreatoicidae of 
Southern Australia and Tasmania really stand in much the same relation 
to other Crustacea as the Monotremata do to normal mammals, and it is 
of interest to enquire whence these peculiar Crustacea have been derived, 
and how it comes about that they are now restricted to this isolated 
corner of the Antipodes. The most striking thing about their distribu¬ 
tion at the present time is the fact that not only are they absolutely 
confined to the temperate parts of the Australasian region, but also to 
the coldest parts of the temporate zone, the majority of the Anaspidacea 
and Phreatoicida? being found at considerable elevations on mountain 
ranges which are covered with snow for at any rate a great part of the 
'winter. They are absolutely unknown from Australia north of the 
Dividing Range. 
Pig:. 3-PARANASPIDES lacustris. 
