xlv Illustrations 



PAGE 



Nereis, the sand worm, attacking; a smaller individual . . 218 



Jaws of the sand worm 219 



An ancient animal of the seashore (trilobite fossil) . . . 222 



Sow bugs 223 



Limulus ; the horseshoe crab 226 



Trilobitelike larva of the horseshoe crab 236 



Horseshoe crab molting 237 



1^'iddler crabs. The male, who is readily distinguished hy his 

 large claw, is toward the left of the picture sitting in the 

 ovenlike entrance to his burrow. The other individual is 

 the female. Pellets of excavated sand can be seen in the 



foreground 241 



Female fiddler crab. The dark mass on her abdomen is a 



brood of eggs and is known as the "sponge" .... 247 



Zoea of the fiddler crab (greatly enlarged) 251 



Greenland whale 260 



Rorqual 263 



Sperm whale 264 



Man-eating shark 272 



Basking shark 273 



Noctiluca (greatly enlarged) 279 



Globigerina; a protozoan. The shell of this minute animal is 

 in the center, and from it radiate stiff spines of lime. En- 

 closing the shell is a frothy mass of living substance from 



which extend numerous fine threads 283 



Shells of radiolarians (greatly enlarged) 285 



Gorgonia; a sea fan 289 



Spicules of Gorgonia (greatly enlarged) 290 



Pennatula; a sea pen 291 



The stone lily; a fossil crinoid which lived in an ancient sea 298 



The sea lily; a living crinoid 299 



