PLATE XXIX. 
Figs. 1-6. THORACASTER CYLINDRATUS, 0. sp. 
Fig. 1. Abactinal aspect; natural size. 
Actinal aspect ; natural size. 
Profile view ; natural size. 
A portion of the abactinal surface ; magnified 10 diameters. / 
. Mouth-plates ; ‘magnified. 
A portion of the actinal surface of a ray, showing adambulacral plates” 
and infero-marginal plates ; magnified 10 diameters. 
