THE MANTLE - CO VERED ANIMALS. 1 33 
of the Nautilus, which, it must be remembered, is 
totally different from the Argonaut shell, being the 
animal's real home and not a mere nest. The 
Nautilus is different in many ways from the octopus 
and the cuttle. He has four breathing gills instead 
of two ; his eyes are much less perfect than those of 
the other head-footed animals ; he has no ink-bag, for 
having a strong protecting shell he has less need for 
it ; and he has no suckers on his feet. He is the last 
remnant of a once great family, that of the huge 
Ammonites and Nautiluses, which we find buried in 
the rocks of ages past ; and, like many a remnant 
of a once noble race, living retired in their own 
domain while younger and less sensitive branches 
are fighting their way to eminence in the world, the 
nautilus creeps in the shallow waters of the Indian 
Ocean, or floats about when all is still, but hides 
himself persistently from view, and has very rarely 
been seen alive. He builds his beautiful and refined 
house chamber by chamber, deserting one after 
another as he grows too large for them, and leaving 
only a thin tube through the middle, by which he is 
supposed to fill the shell with air when he wishes 
to float. 
' ' Year after year beheld the silent toil 
That spread his lustrous coil ; 
Still, as the spiral grew 
He left the past year's dwelling for the new, 
Stole with soft step its shining archway through, 
Built up its idle door, 
Stretched in his last-found home, and knew the old no more." 
He allows very few, however, to investigate his 
habits : wrapped in his proud reserve he lives his 
solitary life, and it is only after his death that his 
