PLATE II. 



Callidebma latum, Forbes, sp. (P. 12.) 



From the Lotver Chalk. 



Fig. 



1 a. Actinal aspect ; natural size. (Coll. Brit. Mus.) 



b. Infero-marginal plates ; magnified 2 diameters. 



c. Actinal intermediate plates ; magnified 3 diameters. 



d. Adambulacral plates ; magnified. 



e. A moutli-plate ; magnified. 



a. Actinal aspect of another example, with a portion of the actinal floor removed, 



showing the stellate bases of the abactinal plates or paxillse ; natural size. 

 (Coll. Brit. Mus.) 



b. Actinal surface of part of the ray ; magnified 1^ diameters. 



c. Infero-marginal plates ; magnified 3 diameters. 



d. Stellate bases of the abactinal plates or paxillee; magnified 4 diameters. 



