THE MANTLE -COVERED ANIMALS. 
125 
And now that the sea-shore, the ponds, and the 
rivers are overrun with stomach-footed animals, there 
remains but the wide ocean. And even there they 
have made their way, for sailors in the Atlantic Ocean 
meet with the ocean-snail (Ianthina), with its float 
of air-cells, floating in myriads over the sea and 
feeding on the small jelly-fish, and with the lovely 
Oceanic Mollusca. 
I, Ianthina, the ocean- snail. /, Foot ; r, raft of air-bubbles, with 
egg-bags hanging down. C, Carinaria.*/; Foot ; s, shell covering the 
breathing-gills, g, both these forms float upside down. P, Pteropod 
or wing-footed snail. 
Carinaria, whose foot has been moulded into fins 
(/, C, Fig. 48) with which it swims upside down in the 
water, its delicate shell serving to protect its breath- 
* Carinaria atlantica. 
