364 ARCTURID2. 
wards and forwards, throwing about its long, inferior 
antenne, and ever and anon drawing them through its 
anterior fringed feet, for the purpose of cleaning them. 
It frequently darts from its branch with the rapidity of 
lightning, to seize with its long antennze some minute 
crustaceous animal, and returns to its resting-place to 
devour its prey at pleasure. In this manner the antennz 
are the only organs employed in seizing and enclosing 
the prey, which they drag to the anterior feet, which hold 
it while it is being devoured. The strong claws with 
which the inferior antenne are armed, seem also to be 
useful to the animal in the act of prehension, and in an 
Antarctic species we find this power increased by the 
presence of strong teeth. 
The formation of the fourth segment of the body, 
together with the antennz (especially the upper pair) 
and the peculiar sculpturation of the surface, afford the 
best specific characters, and will doubtless sufficiently 
separate the three species described by Mr. Goodsir 
from any others that may occur, 
Mr. Goodsir gives a series of details of the internal 
anatomy of these animals, the nervous system consisting 
of a supra-cesophageal ganglion, from which the nerves of 
sense proceed, followed by four ganglions, united by 
double cords, at the base of the four ciliated pairs of 
legs, with three similar ganglia at the basis of the three 
posterior pairs of feet, united to the preceding by a long 
double cord. Two highly developed and distinctly 
defined longitudinal muscles stretch along the dorsal 
aspect of the elongated fourth thoracic segment, their 
office being to enable the animals to erect the anterior 
part of the body on the true formed legs, and affording 
a purchase for the proper action of the powerful clawed 
antennee. 
