544 lepadidjE. 



and the caudal appendages fill up a gap behind, between 

 the cirri of the sixth pair. I at first thought, with Mr. 

 Hancock, that these buttons served to catch the prey ; but, 

 reflecting on their convexity and hardness, they appear very 

 badly adapted for this purpose ; it would, in fact, be a mar- 

 vellous feat to secure, in the dark, any moving object between 

 four balls. On the other hand, this very convexity, the 

 hardness, and especially the crenated ridges, and the power- 

 ful muscles (which from the first surprised me), are all well 

 explained, if we suppose the prey, being secured by the 

 terminal segments, to be triturated between these four balls : 

 any part which escaped upwards would, moreover, be re- 

 tained in a sort of cage, formed by the inwardly inflected 

 terminal segments with their hooked spines. This view 

 of the very curious and unparalleled use made of a modified 

 portion, not of the haunch, but of an upper part of the two 

 posterior pairs of thoracic limbs, is in some degree con- 

 firmed by finding that Cryptophialus, which has apparently 

 analogous habits, requires its food to be triturated, though 

 in this case it is effected by very different means, namely, 

 by four beautifully toothed discs, with brushes of hairs, 

 developed within the lower end of the oesophagus. 



The prey, when caught, would probably at once be carried 

 by the movement of the articulated thorax to the mouth 

 (itself moveable), and being there secured by the mouth in 

 front, the caudal appendages behind, the tips of the cirri 

 above, and the broad pedicels of the first pair on the two 

 sides, it would be triturated by the four crenated buttons, 

 and would then be forced down the oesophagus by the 

 action of the simple jaws. I looked in vain in several 

 specimens for any object within the stomach. I believe, 

 that when the specimens are first taken, all half digested 

 food is ejected by the mouth. Whether we may thus 

 account for the extremely foul condition of the rami of 

 the first cirri in all the many specimens examined by me, 

 I know not ; but that these rami, which are thickly clothed 

 with fine plumose hairs, and are furnished with delicate 

 muscles, act as brushes, so as to clean the orifice of the 

 sack, I can hardly doubt. 



Homologies. — I have as yet, to a certain extent, assumed 



