64 



University of California Publications in Zoology. L^"l. 4 



If still larger crabs or other animals come against the star- 

 fish they quickly withdraw after being seized by a few score of 

 the pedicellariae. Often, of course, the animal carries away a 

 number of the jaws. 



It is clear therefore that in this species of starfish the pedi- 

 cellariae are important defensive organs, playing the chief part 



*>=?■??«'' 



Fig. 2. — Starfish holding six crabs which have been caught by the pedicel- 

 lariae. (The five white Hippas are easily seen; the other crab is dark in 

 color, and is on the disk of the starfish.) Photograph. 



in protecting the starfish from predatory enemies. They are 

 specially serviceable in protecting the delicate gills ; through 

 their prompt and effective action it is almost impossible for the 

 gills to be disturbed in their important functions. 



Detailed Behavior of the Pedicellariae. 



It will be worth while to study more carefully the behavior 

 of these remarkable protective organs. The pedicellariae make 

 almost the impression of independent animals; indeed, it was at_ 

 one time held that they were parasites on the starfish. They have 

 a system of behavior as complete as that of many of the lower 



