PLATE XI. 
Page 
Figs. 1-4. PLuronaster Birrons, Wyville Thomson, sp. . 84 
. Abactinal aspect ; magnified 2 diameters. 
. Actinal aspect ; magnified 2 diameters. 
. A young example, abactinal aspect ; magnified 6 diameters. 
. A young example, actinal aspect ; magnified 6 diameters. 
[For magnified details of this species see Pl. XIII. figs. 9, 10. | 
Figs, 5, 6. PLUTONASTER AMBIGUUS, 0. sp. . ‘ : 95 
. Abactinal aspect ; magnified 3 diameters. 
. Actinal aspect; magnified 3 diameters. 
[For magnified details of this species see Pl. XIII. figs. 11, 12.] 
