PLATE XII. 



Metopaster Parkinson!, Forbes, sp. (Page 31.) 



From the Upper GhalJc. 

 Fig. 



1«. Abactiiaal aspect ; natural size. (Coll. Brit. Mus.) 

 h. Lateral view of the margin ; natural size. 



c. A supero-marginal plate ; magnified. 



d. The madreporiform body ; magnified. 



e. Abactinal intermediate plates ; magnified. 



Metopaster zonatuj;, Sladen. (Page 45.) 



From the Tipper Ghall\ 



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

 h. Lateral view of tlie margin ; natural size. 

 c. The madreporiform bod}^ ; magnified. 



MiTRASTER HuNTEKi, Fm'bes, sp. (Page 59.) 

 From the Upper Chalk. 



3fl. Actinal aspect; natural size. (Coll. Brit. Mus.) 



b. Lateral view of the margin ; natural size. 



c. A supero-marginal plate ; magnified. 



d. An infero-marginal plate ; magnified. 



e. Actinal intermediate plates ; magnified. 



Callidekma mosaicum, Forbes, sp. (Page 9.) 

 From the Lower Chalk. 



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



b. Lateral view of the margin ; natural size. 



c. Mouth-plates ; magnified. 



d. An infero-marginal plate ; magnified. 



