4.96 GEOFFREY SMITH. 
We may describe, as a type, the general appearance of 
A. tasmanie, the mountain-shrimp of Tasmania, found in 
the pools of rivers and in tarns at a high elevation. The 
chitinous integument is soft and uncalcified, and of a straw- 
yellow colour ; beneath it in the skin are numerous branching 
black chromatophores, arranged in a similar pattern on each 
seoment. Along the dorsal middle line two dark lines are 
visible, which are caused by the pigmentation on the floor of 
the pericardium. 
In the natural position the body is held straight and un- 
TExT-FIG. 1. 
——s 
Pp: Th.8 -Ab/ 
Paranaspides lacustris, 9. Lateral view... x 4. a. First 
antenna. a?. Second antenna. md. Mandible. ep. Gills. 
Th. 8. Eighth thoracic segment. Ab. 1. First abdominal 
segment. Pl. 1. Hirst abdominal appendages. 1’. Telson. 
U. Uropod. 
flexed with the limbs disposed in the characteristic manner 
shown in Pl. 11, fig. 1. The normal habit of the animal is to 
walk or run upon the stones at the sides or bottom of the 
deep pools in which it lives ; this walking movement is effected 
by the endopodites of the eight thoracic limbs, but it is also 
assisted by the long exopodites of the abdominal appendages. 
‘he exopodites of the thoracic limbs are kept im a continual 
waving motion, and no doubt aid in respiration by agitating 
