A ROCK-POOL BY TTTE SEA 



169 



of various shades and tints of red, 

 orange, purple and brown. What 

 rough, horny backs they have, and yet 

 they can bend their rays into so many 

 different positions, and the delicate 

 white tentacles on the under side wave, 

 as the rays are lifted, almost as grace- 

 fully as those of the anemone. 



I once saw one swallow a small 

 snail, shell and all. The star-fish was 

 clinging to the side of the glass jar 

 which was its temporary home, and 

 had spread itself over the small, nearly 

 round shell of the littorina, which 



of its tentacles. In this way it can 

 eat even mussels and oysters, covering 

 its victim with a poisonous fluid, thus 

 causing the shell to open, when the 

 star-fish quickly devours the contents. 

 I have seen one during this process, the 

 thin membrane which forms the stom- 

 ach appearing like a large white bubble. 

 Oystermen consider the star-fish an 

 enemy, it makes such havoc in the 

 oyster-beds. 



The sea-urchins or sea-chestnuts are 

 not beautiful creatures. They look 

 much like chestnut burrs, but are 



A GEM IX SEA ALGAE FROM A ROCK-POOL 



(Callithamnion corybosum) 

 One hundred and fifty varieties 



looked much larger than the star-fish's 

 mouth. When I left the room, the 

 poor littorina was gradually disappear- 

 ing, only a small part of the shell being 

 visible, and, on returning, I hunted 

 through the jar in vain for the bright 

 yellow shell. But the star-fish became 

 the liveliest of its kind in the aquarium, 

 and never showed any sign of indiges- 

 tion. 



The • asterias inverts its stomach 

 upon whatever of its prey is too large 

 to be drawn into its mouth by means 



darker in color ; and the burrs in the 

 woods do not have the power to send 

 out long tentacles from their spines, 

 and work themselves slowly around, 

 using the little suckers at the end of 

 these tentacles as feet. The digestive 

 system of the sea-urchin is remarkable. 

 Its skeleton consists of no less than 

 thirty pieces. The teeth, which form 

 part of this wonderfully jointed skele- 

 ton, are five in number, long, sharp, 

 curved, and very hard. They can cut 

 the hardest substances, and would soon 



