133 



Fig. 17. Ceratopora jacksoni. (a) The type specimen natural size; (/o longitudinal 

 section of a calyx, showing bud, and absence of cysts in the upper part. x2}^ ; (c) cross- 

 section of calyx, and bud, x 2^ ; (d, e) cross-sections of corallites, showing the cysts and the 

 central living chamber, also the spines or trabeculae, x 5 ; (/) longitudinal section of a cor- 

 allite, x5. The dark shading indicates cavities filled with mud, the light shading those rilled 

 by crystalline calcite. (Original.) 



