v ANASPIDACEA Tae 
the anterior thoracic region, The auditory organ is at the base 
of the first antennae. 
Order. Anaspidacea. 
Fam. 1. Anaspididae.—The mountain-shrimp of Tasmania, 
Anaspides tasmaniae, was first described by Thomson! in 1893 
from specimens taken in a little pool near the summit of Mount 
Wellington ; it was redescribed by Calman,’ who drew attention 
to its remarkable resemblance to certain Carboniferous fossils of 
Europe and N. America (Gampsonyx, Palaeocaris, ete.). 
The creature appears to be confined to the deep pools of the 
rivers and tarns on the mountains of the southern and western 
portions of Tasmania.’ The waters in which it occurs are always 
cold and absolutely clear, and there is no record of its living at 
altitudes much below 2000 feet, while it frequently occurs at 
4000 feet. The body may attain upwards of two inches in 
length ; it is deeply pigmented with black chromatophores, and 
it is held perfectly horizontal without any flexure. The animal 
rarely swims unless disturbed, usually walking about on stones 
and water-plants at the bottom of deep pools. In walking the 
endopodites of the thoracic limbs are chiefly instrumental, but 
they are assisted by the exopodites of the abdominal limbs. 
When frightened the shrimp can dart rapidly forwards 
or sideways by the strokes of its powerful tail-fan, but it never 
jumps backwards as do the other Malacostraca. It appears to 
browse upon the aigal slime covering the rocks and on the 
submerged liver-worts and mosses, but it does not refuse animal 
food, even feeding on the dead bodies of members of its own 
species. The thoracic limbs, which are all biramous except the 
last pair, carry a double series of remarkable plate-lke gills on 
their coxopodites. The slender and setose exopodites of the 
thoracic limbs are respiratory in function, being kept im continual 
motion even when the animal is at rest, and serving to keep up a 
current of fresh water round the gills. 
Anaspides shows a remarkable combination of structural 
characters, some of which are peculiar, while others are possessed 
in common with the Peracarida or Eucarida. The chief peculiar 
1 Trans. Linn. Soc. (2), vi., 1894-1897, p. 285. 
‘ 
2 Trans. Roy. Soc. Edinburgh, xxxviii., 1897, p. 787. 
3G. Smith, Proc. Roy. Soc. 1908. 
