Five-Fingered Jack on the Oyster. 47 



confounded with them, for their arms are found to radiate from 

 a clearly defined central disk, and there is no prolongation of 

 their stomachs and ovaries into their interiors. The tube- 

 feet pass out from the plates along the sides of the arms, 

 instead of from the under surface as in the Star-fishes proper, 

 and probably serve merely as a help for breathing, locomo- 

 tion over the sands being effected by their long flexible arms. 

 Their home is chiefly among the tangle and eel-grass, where 

 their protecting covering affords them security from their 

 many enemies. 



