PLATE X. 



Metopastek Paekinsoni, Forbes, sp. (Page 31.) 



From the Upper Chalk. 

 Pig. 

 1. Abactinal aspect; natural size. (Coll. Brit. Mus.) 



2 a. Abactinal aspect of another example; natural size. (Coll. Brit. Mus.) 



b. A supero-marginal plate ; magnified 3 diameters. 



c. The madreporiform body ; magnified. 



d. An abactinal intermediate plate, with pedicellarian apparatus ; magnified. 



3 a. Actinal aspect of another example; natural size. (Coll. Brit. Mus.) 



b. Lateral view of the margin ; natural size. 

 0. Adambulacral plates ; magnified. 



4a. Actinal aspect of another example; natural size. (Coll. Brit. Mus.) 

 h. An inf'ero-marginal plate ; magnified. 



c. An actinal intermediate plate ; magnified. 



5 a. Abactinal aspect of a young (?) example ; natural size. 



b. A supero-marginal plate of the same ; magnified 4 diameters. 



c. Abactinal intermediate plates ; magnified. 



