364 ARCTURID;^. 



wards and forwards, tlirowing about its long, inferior 

 antennee, 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 antennae some minute 

 criistaceous animal, and returns to its resting-place to 

 devour its prey at pleasure. In this manner the antennae 

 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 antennee 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 antenna (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-oesophageal 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 

 antennae. 



