58 



ZOOLOGY. 



Classes op Bchinodbrmata. 



1. Body mounted on a stalk Crinoidea. 



2. Body with five arms; free Asteroidea. 



3. Body spherical, with long spines Echinoi<ka. 



4. Body elongated; skin soft, hardened hy Ta.iu\i\,ex>\aXea.IIoloihuroidea, 



Fio. 63. — a, PentacHnus caput-Tned^isoE, half natural size; fc, calyz-dlst seen 

 from above, natural size. 



The existing Crinoids live in very deep water. Penta- 

 crimis cap ut-med usee (Fig. C3) lives attached to rocks in 

 the West Indies; otliers live in the Atlantic Ocean, some- 

 times at the great depth of neaidy three miles. A free 

 Crinoid {Antedoii, Fig. G4) lives in rather shallow water, 



