CRUSTACEA. 207 



the lines, renders it probable that the habit of sail- 

 ing through the air is as characteristic of this tribe, as 

 that of diving is of the Argyroneta. We may then 

 reject Latreille's supposition that the gossamer 

 owes its origin indifferently to the young of several 

 genera of spiders ; although, as we have seen, the 

 young of other spiders do possess the power of 

 performing aerial voyages.* 



During our difierent passages south of the Pla- 

 ta, I often towed astern a net made of bunting, 

 and thus caught many curious animals. Of Crus- 

 tacea there were inany strange and undescribed 

 genera. One, which in some respects is allied to 

 the Notopods (or those crabs which have their pos- 

 terior legs placed almost on their backs, for the 

 purpose of adhering to the under side of rocks), is 

 very remarkable from the structure of its hind pair 

 of legs. The penultimate joint, instead of termi- 

 nating in a simple claw, ends in thi'ee bristle-like 

 appendages of dissimilar lengths — the longest 

 equalling that of the entire leg. These claws are 

 very thin, and are serrated with the finest teeth, 

 directed backwards : their curved extremities are 

 flattened, and on this part five most minute cups 

 are placed, which seem to act in the same manner 

 as the suckers on the arms of the cuttle-fish. As 

 the animal lives in the open sea, and probably 

 wants a place of rest, I suppose this beautiful and 

 most anomalous structure is adapted to take hold 

 of floating marine animals. 



In deep water, far from the land, the number of 

 living creatures is extremely small : south of the 

 latitude 35°, I never succeeded in catching any- 

 thing besides some beroe, and a few species of 

 minute entomostracous Crustacea. In shoaler wa- 



* Mr. Blackwall, in his Researches in Zoology, has many ex- 

 cellent observations on the habits of spiders. 



