PLATE XXIX 



From iJie Upper and Lower Chalk. 



. 1 a. Glyph ocYPH us radiatus, Hmiinghaus, sp. Test, upper surface, magnified 



twice. (P. 121.) 

 1 ^- „ ,, Lateral view, magnified twice. 



1 c. „ „ Areal plates and zones, do. ten times. 



2 a. ^, Under surface, do. twice. 



2 6. „ „ Apical disc (from M. Cotteau's figure), magnified. 



2 c. Areal plates and zones (do. do.) do. 



2 d. „ „ Inter-ambulacrum (do. do.) do. 



2 e. „ ^, Ambulacrum (do. do.) do. 



3 a. EcHiNOTHVRiA YLORis, JFoodivard. Portion of test, natural size, in the British 



Museum. (P. 125). 



3 „ „ Poriferous zones, magnified four times, do. 



4 a. „ Do. do., do. do. 



4 ^- „ „ Portion of spine, do. six times. 



4 c. „ „ Do. do., do. do. 



4 d. „ Areal plates, do. four times. 



5 a. „ „ Ovarial plates, natural size. 



5 (j „ „ Jaws, forming " the Lantern of Aristotle," 



natural size. 



