On some West-Australian Entomostraca. ial 
algæ contained in the aquarium. More frequently it was 
seen to move about along the bottom, with the back always 
upwards, and burrowing the frontal part more or less deeply 
into the mud. During its passage, the loose muddy particles 
were whirled up by the violent swinging movements of the 
legs, and thereby, apparently, feeding matter brought within 
reach of the mouth. At times it was seen to ascend 
the walls of the aquarium or the stems of plants growing 
in it, clinging with great dexterity to the outmost ramifica- 
tions in search of food. It also not infrequently swam 
with great rapidity through the water, twisting about in all 
directions. The movements, which were extremely graceful, 
were chiefly effected by the rhythmical swinging of the legs, and 
generally constituted a rather even dart through the water; 
but this dart might be suddenly altered in any direction by 
the bending of the extremely flexible posterior part of the 
body. The epipodites and exopodites of the exposed legs 
were seen to be in uninterrupted rapid vibratory motion, 
apparently not coincident with the movements of the legs 
themselves; and by this means a constant renewal of the 
water beneath the carapace might be effected, to assist the 
respiratory process. The capacious intestinal tube was always 
filled with dark contents, and at times long coherent portions 
of the latter were seen to be expelled from the anal orifice. 
The animal casts its skin several times, and with each exu- 
viation it increased considerably in size. No less than 6 
more or less complete exuviæ were taken up from the aqua- 
rium, and preserved for subsequent examination. On the 
29th June the individual showed trace of disease, and I 
therefore hastened to take it up for examination while 
still living. It was found that a sharp splinter of some 
weedy matter had penetrated the mouth, and probably 
