PLATE I. 

 Calliderma Smithi^, Forbes, sp. (P. 6.) 



From the Loiver Chalk. 



Fis. 



la. Actinal aspect; natural size. (Coll. Brit. Mus.) 



b. Lateral view of the margin ; natural size. 



c. Infero-marginal plates ; magnified 2 diameters . 



d. Lateral view of the marginal plates ; magnified. 



e. Adambulacral plates ; magnified. 



/. Actinal intermediate plates ; magnified 3 diameters. 



