PLATE LXIIa. 



MiciiASTER coR-BOVis, Forbes. 



From the Upper White Chalk. 



Fig. 1. Base of large test, natural size. British Museum. (P. 276.) 

 2 a. Upper surface do. 



b. Lateral view do. do. 



c. Anterior border, anteal sulcus, and mouth opening. 



d. Posterior border, with vent and periprocte. 



MiCRASTER BREVIPORUS, AffttSSh. 



From the Upper White Chalk. 



Fig. 3 a. Upper surface, natural size. My collection. (P. 27S.) 

 b. Under do. do. 



