Fig. 435. A diagram of the 

 apical nervous system of 

 Antedon. From Sedgwick, 

 after Ludwig. a. axial cords 

 of the arms; B i, first 

 brachial ossicle ; CD, centro- 

 dorsal ;Ri,R2,R3, radials . 



B 



VN 



amb— 



por. 



Fig. 436 Pelmatozoa. A, Rhizocrinus, x about zh From Sars. B, Thecal 

 plates of a cystoid with diplopores. C, Plates with pore-rhombs. D Edrio- 

 aster bigsbyi. After Bather, amb. ambulacra on which the covering plates 

 reniam; An. anus; ftp. flooring plates of ambulacra; ia. interambulacrum • 

 mad. madreponte; penst. peristome; por. pores (for tube feet.?) 



