PLATE XIII. 



Pentagonastee megaloplaXj Sladen. (Page 27.) 



From the Upper Chalk. 

 Fig. 



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

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



Metopaster Mantelli, Forhes, sp. (Page 38.) 

 From the Tipper Ghalli. 



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



h. A supero-marginal plate (much weathered) ; magnified 3 diameters. 



c. The madreporiform body and surrounding plates ; magnified. 



d. Abactinal intermediate plates ; magnified 6 diameters. 



3 a. Abactinal aspect of the example figured by Forbes ; natural size. (Coll. 



Brit. Mus.) 

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



4 a. Actinal aspect of another example figured by Forbes ; natural size. (Coll. 



Brit. Mus.) 

 h. An infero-marginal plate ; magnified 3 diameters. 



