482 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1962 



Figure 14. — A, biserial crinoid. B, cross se tion of pinnules in A. C, Platasterias, and D, 

 cross section of metapinnules of same; E, developing pinnule and tentacle in young 

 crinoid; F, tentacles (tube-feet) in Platasterias, G, tube-feet in Luidia. H, optical section 

 of developing pentacrinoid stage of young crinoid; I, similar aspect of young asterozoan. 

 Abbreviations: 1, centrodorsal; 2, radial plate; 3, proximal brachial (ambulacral) ele- 

 ment(s); 4, stomach; 5, caecum of stomach; 6, perivisceral coelom; 7, tube-foot (tentacle). 



