PLATE LXIII. 



Epiaster gibbus, Lamarck. 



From the Upper White Chalk. 



Fig. 1 a. Upper surface, natural size. My collection. (P. 267.) 

 h. Under do. do. 



c. Lateral do. do. 



d. Posterior do. do. 



e. Anterior do. do. 



/. Apical disc, magnified four diameters. 



g. Ambulacral and inter-ambulacral plates, magnified three times. 



h. Structure of the poriferous zones, magnified. 



i. Primary tubercles on upper surface do. 



k. Do. do. from basal do. do. 



