22 THE LIVING WORLD. 
oars. Thus it was likened to the fabled Argo and her precious cargo. The 
latter name, nautilus , was applied because of the frailty of the shell. This little 
animal is both dainty and exquisitely beautiful, on account of which it has 
been made the theme of many poets, who liken it unto an animated ocean idyl. 
SPECIMENS OE SEA-URCHINS TAKEN FROM THE CHALK FORMATION. 
