126 LIFE AND HER CHILDREN. 
ing-gills (g). And as the Carinaria swims along 
he feeds on other and minute univalve animals, 
such as the sea-nymphs and wing-footed snails 
(Pteropods), which discolour the water for miles 
with their swarms, as they graze on the floating 
seaweed. 
Life then has spread her mantle-covered children 
far and wide over sea and land, where each by 
different devices finds food and shelter. But it is not 
with such tiny beings as these that we are to end 
the history of the mantle-covered animals ; for lurking 
in the holes and tide-pools of the sea, there are 
much larger creatures with sac -like bodies, green 
staring eyes, horny beaks, and waving arms, which, 
unlike as they are to the ordinary shell -animals, are 
nevertheless true mantle-bearers. 
Who would imagine, on seeing a cuttle-fish with 
its large pathetic eyes, thrown up on the sea-shore, or 
an octopus shooting across its tank, that these intelli- 
gent, active creatures had any connection with the 
helpless oyster or timid periwinkle ? Yet so it is ; 
only while the oyster is one of the lower and feebler 
forms, the cuttle-fish, the octopus, the argonaut, and 
the nautilus, are the monarchs of the mollusca, pro- 
vided with as powerful weapons for their work as 
the dragon-fly is among insects or the tiger among 
beasts. 
Go some day and look at an octopus in one of the 
aquariums. Its bag-like body appears to be a mere 
mass of flesh ; yet it has really a most complicated 
internal structure, and a gristly framework more like 
a true skeleton than any other animal without a back- 
