PLATE XXX. 



From ihe Neocomian or Lower Greensand. 



Fig. 1 ft. Pkltastes Wrightii, i)e5or. Test, natural size. British Museum. (P. 150.) 



b. „ „ Upper surface, showing disc magnified twice. 



c. „ „ Under surface, mouth opening and peristome, 



magnified twice. 



ri- „ „ Lateral view of the same, magnified twice. 



p- „ „ Upper portion of an inter-ambulacral and ambu- 



lacral area, magnified four times. 



/■ ,, ,, Inter-ambulacral tubercle, magnified four times. 



Fig- 2. „ „ Abnormal disc, suranal absent, do. twice. 



