Illustrations xiii 



PACE 



Prickh- wort; a floweriivj; plant of the seashore .... 138 



Salt wort; a flowering plant of the seashore I39 



Footprints of a herring gull I44 



A staphylinid, or scavenger beetle. This insect lives on the 



decaying matter at the high-tide mark 147 



Robber fly attacking its prey 148 



Larva of the tiger beetle I55 



Cicindela; the tiger beetle . . 158 



Tube sponge. A non-calcareous sponge 167 



Clava; a colony of tubularian hydroids (enlarged) . . . 179 



Hydractinia; a colony of tubularian hydroids (photograph 

 made of the living animals growing on a shell occupied by 



a hermit crab; greatly enlarged) 180 



Rock crab concealing itself in the sand. The animal is in 

 the center of the picture. The fore part of its body and 



the ends of its claws are the only portions exposed . . 188 



Lady crab 196 



Loligo ; a squid (photograph taken on the bottom of a tide 



pool) 200 



Eggs of the squid, attached to a clump of red seaweed. Each 

 of the cylindrical objects is composed of a group of eggs 



numbering many hundreds 202 



Baby squid; just hatched (greatly enlarged) 203 



Octopus, or devilfish 204 



Cuttlefish 207 



Meckelia; the ribbon worm, wnth proboscis partly extruded 211 



Eggs of a flatworm laid on the glass side of an aquarium 



(enlarged) ^ 212 



The mason w^orm 213 



Serpula; a tube-building worm. This creature has built its 



tube on the dead shell of a whelk 214 



Polycirrus; the blood worm 215 



