PLATE XXI». 



Echinobrissus receus, /. 1, 2. 



1. Seen from the actinal side, Jj5-. 



2. Same, from tlie abactinal pole, ^^. 



Platybrissus Roemeri,/. 3, 4- 



3. From the abactinal side, nat. size. 



4. From the actinal side, nat. size. 



liintbia australis, /. 5-7. 



5. Seen from the abactinal side, nat. size. 



6. Same, from the actinal side, nat. size. 



7. Same, seen in profile, nat. size. 



Metalia maculosa,/. S, 9. 



8. Seen from the actinal side, f nat. size. 



9. From the abactinal pole, f nat. size. 



