2-0 VERTEBRATA. 



quite destitute of suckers. Its gills or branchias are four in number instead 

 of two, the head is covered with a strong leathery hood, which, when the 

 animal retires into its shell, closes the orifice like a door. In place of the 

 eight sucker-bearing arms of the Poulpe, there are forty tentacular appendages, 

 which can be protruded or retracted at pleasure, and the mouth is surrounded 

 with a series of tentacles still more numerous. The nautilus is, moreover, 

 unprovided with an ink-bag ; its beak is thick and of stony hardness, appa- 

 rently adapted to crush shells or corals, which most probably constitute its 

 ordinary food. 



The Nautili are not found in any great depth of water, but principally in- 

 habit the reefs near which their food is most abundant. They creep about 

 these reefs, with their shell uppermost, like a snail, and devour crabs and 

 other Crustaceans that come in their way, or they return and remain in a chasm 

 of the rock, with their numerous tentacles spread out in all directions, wait- 

 ing for prey to approach near enough to be captured. The feelers are very 

 numerous, and evidently endowed with a keen sense of touch, but are quite 

 destitute of the sucking disks so remarkable in the cuttle-fish. When at the 

 surface of the water, the Nautilus Pompilius drifts with the current or breeze ; 

 its navigation is passive, or at most influenced by the jets of water expelled 

 occasionally through the funnel. The natives of the New Hebrides, New 

 Caledonia, and the Fiji groups of islands capture it and use it as an article 

 of food. When the water is smooth, so that the bottom at several fathoms 

 of depth can be distinctly seen, the fisherman in his canoe scrutinizes the 

 sands and the coral rocks to discover the animal in its favourite haunts. 



CHAPTER XXII. 

 VERTEBRATE ANIMALS. 



THE second grand division of the animal creation is com- 

 posed of four great classes, closely allied to each other in 

 the main features of their organization, and possessing in common 

 a general type of structure, clearly recognizable in every member 

 of the extensive series, although, of course, modified in accordance 

 with the endless diversity of circumstances under which particular 

 races are destined to exist. 



The immeasurable realms of the ocean, the rivers, the lakes 

 and streams, the fens and marshy places of the earth, the frozen 

 precincts of the poles, and the torrid regions of the equator, have 

 all appropriate occupants, more favoured as regards their capacity 

 tor enjoyment, and more largely endowed with strength and 

 intelligence, than any which have hitherto occupied our attention, 

 and gradually rising higher and higher in their attributes until 

 they conduct us at last to Man himself. 



Pishes, restricted by their mode of respiration to an aquatic 



