PLATE XXV. 



ECHINOBRISSl FROM THE GrEAT OoLITE, AND CoRNBRASH. 



Great Oolite Species. 



J a. EcHiNoBRissus GiaESBACiiii, lFri(/ht, p. 340. Upper surface, natural size. 

 h. Up])er surface of the same, magnified twice. 



c. Under svnface, natural size. 



d. Ditto, magnified twice. 



e. Lateral view of the test, natural size. 



/. Ambulacra] area, poriferous zones, and inter-arabulacral plates, magnified four times. 



Cornbrash Species. 



2 a. EcHiNOBRissus ORBICULARIS, Phillips, p. 341. Upper surface, natural size. 

 h. Under surface of the same test, natural size. 



c. Lateral view of ditto, showing the poriferous zones. 



d. Apical disc, with its internal complementary plates, magnified five times. 



e. Ambulacral area, poriferous zones, and inter-ambulacral plates, magnified thrice. 

 /. Lateral view of a couoidal variety of this species, from Northamptonshire. 



y. Upper surface of another specimen, showing a greater eccentricity of the apical disc, 

 a wider anal valley, and a larger vent. 



