PLATE LXXV. 



Echinospatagus Renevieri, Wright. 

 From, the Lower Greensand, Shanklin Isle of Wight. 



Fig. 1 a. Upper surface, natural size. Monsieur De Loriol's collection. (P. 285.) 



b. Under do. do. 



c. Lateral view do. 



d. Primary tubercles, under surface. 



e. Do. upper do. 



Echinospatagus Quenstedtii, Wright. 

 From the Tipper Greensand, Wiltshire. 



Fig. 2 a. Upper surface, natural size. My collection. (P. 286.) 



b. Under do. do. 



c. Lateral view do. 



Micraster brevis, Desor. 

 From the Chalk of Corbieres and Craie a Hippurites. 



Fig. 3 a. Upper surface, natural size. My collection. 



b. Under do. do. 



c. Lateral view do. 



e. Apical disc, and terminations of the ambulacra much enlarged. 

 /. Primary tubercles from the under surface, enlarged to show the deep areola; 



and circles of granules. 

 g. Ambulacral area, poriferous zones, and interambulacral plates, enlarged three 

 diameters, to show the structure of the surface sculpture of the test. 

 Fig. 2 d. Non-petaloid portion of the ambulacra. 



