DERMATODIADEMA HORKIDUM. 



7 3 ram. 



Fig. 117. D. horridum. 



advanced stages of growth (Pis. 26, fig. 1 ; 28, fig. / ; 29, figs. 3, 4)- In a 

 young specimen of 7.3 inm., Fig. 117, the primordial plates have been 

 resorbed, and the first pair of interambiilacral plates are in contact with 

 the actinal system. There are twelve to thirteen ambulacral plates, six 



2) 



10.5 mm. 

 Fig. 118. D, HORBIDUM. 



