EXPLANATION OF PLATE XIL 



CATru'vci's \\■1LI.I.\^[SI Clark n. sp p. 292 



(Illustrations contributed by Dr. W. B. Clark.) 

 1-4. Ventral, dorsal, posterior and lateral \iews of a complete in- 

 dividual. 



Niii'csiiik marl: bluff cast of Atlantic Hi;^lilaiuii. 



C.\ssiDULUs AEQUOREus jMorton p. 293 



(All ligures after Clark.) 

 5-8. Posterior, lateral, ventral and dorsal views of tlie t\"pe speci- 

 men from Alaliania. 

 9. Anterior ambulacrum enlargeil. 



10. Sexeral ambulacral plates from the petaloid region, much 



enlarged. 



11. Se\'eral aminilacral plates from the oral region. 



12. .Vijical disk, jnuch enlarged. 



/ 'iiiccuf":ca liiucsaiul. 



904 



