32 THE DEPTHS OF THE SEA 



living animals, of volcanic and meteoric dust, and of 

 small pieces of water -logged pumice-stone.' On 

 whichever deposit we found ourselves, could we but 

 see the prospect, we should be struck with the 

 monotony of a scene as different as can well be 

 imagined from the variegated beauty of a rock-pool 

 or a coral island lagoon. 



There is, however, an abundance of animal life. 

 The dredge reveals a surprising variety and wealth 

 of form. Sir John Murray records ' at station 146 in 

 the Southern Ocean, at a depth of 1,375 fathoms, that 

 200 specimens captured belonged to 59 genera and 

 78 species.' He further states that this was ' probably 

 the most successful haul, as regards number, variety, 

 novelty, size, and beauty of the specimens,' up to the 

 date of the dredging; but even this was surpassed by 

 the captures from the depths at station 147. The 

 Southern Ocean is particularly well populated. The 

 same writer says : ' The deep-sea fauna of the Ant- 

 arctic has been shown by the Challenger to be excep- 

 tionally rich, a much larger number of species having 

 been obtained than in any other region visited by the 

 expedition; and the Valdivia's dredgings, in 1898, 

 confirm this.' There seems to be no record of such 

 a wealth of species in depths of less than 50 fathoms, 

 and we are justified in the belief that the great depths 

 are extremely rich in species. 



The peculiar conditions under which the Benthos 

 live have had a marked influence on their structure. 

 Representatives of nearly all the great divisions of 

 the animal kingdom which occur in the sea are found 

 in the depths. Protozoa, sponges, coelenterata, round- 

 worms, annehds, Crustacea, polyzoa, brachiopoda, 

 molluscs, echinoderms, ascidians, fishes, crowd the 

 sea-bottom. The Valdivia has brought home even 

 deep-sea ctenophores and sagittas, forms hitherto 

 associated only with life at the surface. The same 



