13° FIRST LESSONS IN ZOOLOGY 



and darkness. On the under side the mouth is in 

 tlie eenter, antl from it along each ray runs a groove. 

 In each groove may be seen two double rows of soft, 

 tubular processes with sucker-like tips called the tube- 

 feet. These are the organs of locomotion. If live star- 



Fig. 07. — Starfishes of various kinds in a tide-pool on the Bay of Monterey. 

 California; note two with five rays, three pentagonal, and two with 

 many rays; also see larcje sea-urcjiins. (Photograph by author, from 

 living spccinii-ns /// si'/j/.) 



fishes can be watched the slow locomotion by means 

 of the tube-feet may be seen, and perhaps also the 

 peculiar mode of taking food. Starfishes are carnivo- 

 rous, feeding on crabs, snails, and the like. If the live 

 ])rey is too large to be taken into the mouth it is stir- 

 rounded by the stomach, which is pushed outward for 

 this purpose. It secretes fluids which kill the prey, after 

 which the soft parts are digested. 



