CRUSTACEA 171 



this tribe, as that of diving is of the Argyroncta. 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 different passages south of the Plata, I often 

 towed astern a net made of bunting, and thus caught, many 

 curious animals. Of Crustacea there were many strange and 

 undescribed genera. One, which in some respects is allied to 

 the Notopods (or those crabs which have their posterior 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 

 terminating in a simple claw, ends in three 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 float- 

 ing marine animals. 



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

 creatures is extremely small: south of the latitude 3 5°, I never 

 succeeded in catching anything besides some beroe, and a few 

 species of minute entomostracous Crustacea. In shoaler water, 

 at the distance of a few miles from the coast, very many kinds 

 of Crustacea and some other animals are numerous, but only 

 during the night. Between latitudes 56° and 57° south of 

 Cape Horn, the net was put astern several times ; it never, 

 however, brought up anything besides a few of two extremely 

 minute species of Entomostraca. Yet whales and seals, petrels 

 and albatross, are exceedingly abundant throughout this part 

 of the ocean. It has always been a mystery to me on what 

 the albatross, which lives far from the shore, can subsist ; I 

 presume that, like the condor, it is able to fast long ; and that 

 one good feast on the carcass of a putrid whale lasts for a long 



' Mr. Elackwall, in his Researches in Zoology, lias many excellent observations 

 on the habits of spiders. 



