13-t 



and thr()ii»2,li the foriiiation of coarse cysts. No true tabiila3 

 are known ; the polypites in some of the species apparently 

 remained connected throughout the life of the colony, 

 while in others the cavities of the corallites are sejiarated 

 by a spicular partition. Sui-face formed by a wrinkled 

 epitheca. 



Ceratopoka .lACKsoNi. Grabau. (Fii;-. 17.) (1899: Proc. 

 Boston Soc. Nat. History, Vol. XXVlll, p. 415, Pis. I., IT.) 



Distinguishiii<>' (liaracters. — Erect, irregular, and fre- 

 ([uently-branching coralluni; cylindrical or trumpet-shaped 

 corallites; coarsely wrinkled epitheca with costal ridges; 

 coarse, irreguhir internal cysts, arranged semi-concentric- 

 ally, with fre(|uent projecting spine-like ])i-ocesses. 



Fig. 18. Cevdtopora dichotoma. (a-d) Specimens viewed from different positions, sliow- 

 ing the flattened under side, the calyx, carination, and lines of growth, x 3 ; (e) specimen 

 seen from below, showing the characteristic mode of branching — natural size; (/) longi- 

 tudinal section of the |)r<)cuMil)ent portion of a corallite, showing the living chamber and 

 the cysts, x 5; ((/) transverse section of procumbent tube, showing central cavity, cysts, 

 and hollow carina, x 7. (( trigiiial.i 



