CRINOIDS. 



241 



tail. They are found on nearly all coasts, and are at 

 once distinguished by a small disk or central portion 

 from which the rays start off very abruptly, instead of 

 the gradual passage of the central part into the arms, 

 as seen in the true Starfishes. They move about by 

 bending their arms, whose hold is aided by their spine. 

 Nearly all have the arms simple. Figure 469 ; but some 

 have the arms much branched, Figure 470. 



CRINOIDS. 



The word Crinoid means lily-like in form, and is 

 given to a large number of Echinoderms on account of 

 their lily-like or plant-like appearance. Only a small 



Fig. 471. — Living Crinoid — Pentacrinus caput-medusae. West Indies. 



number of these animals are now living. Of the few 

 living ones, some kinds have a stem, in the adult state. 



NAT. HIST. AN. — 16 



