PLATE 18. 



Fig. 1. 421. 1. Cannapora jctnciformis. (Pag. 43.; 



1 a. A portion of a liemisplieric mass, showing the mode of growth, 



1 b. A small fragment where tlie tubes are parallel. 



1 c. Showing the tubes surroundhig and radiating from some foreign cylindrical body, upon which the polyps 



have grown . 

 1 d. Several tubes enlarged. 



1 c. Transverse section, showing the stellate orifices of the tubes. » 



1 f. A similar section, where the cells are hollow. 



Fig. 2. 422. 1. Catenipora escharoides. (Pag. 44.) 



Fig. 3. 423. 1. Heloposa fragilis. ( Pag. 44.) 



3 a. Fragment of the ordinary character. 3 6. A fragment showing the thickened termination. 



3 c. A specimen having a single branch, the stipe and branch both having enlarged extremities. 

 3 d. The specimen 3 b enlarged. 3 c. A portion of another specimen enlarged. 



3 /. A small specimen of limestone with fragments of this coral upon its surface. 



Fig. 4. 424. 7. Stictopora crassa. (Pag. 45.) 



4 ffi & 6. Two fragments, natural size. 



4 c. A. portion enlarged, showing the striated surface of the intercellular spaces. 



Fig. 5. 42-5. 8. Stictopora raritora, (Pag. 46.) 



5 a, b. Two specimens of tliis species. 5 c. A portion enlarged. 



Fig. 6. 426. 1. PhjEnopora explanata. (Pag. 46.) 



6 a. A small unworn fragment, of tlie natural size. 



6 b Sf d. A similar fi-agmout, with the surface somewhat abraded. 



6 «. A portion enlarged. 



Fig. 7. 427. 2. Ph^nopora constellata. (Pag. 47.) 



7 a. A portion of a large specimen, showing the entire width of the stipe, The specimen shows only the 



bases of the cellules, the upper portion with tlie centre having been broken away. 

 7 b. A fragment presenting casts of the cellules, the calcareous matter being removed. 

 7 c. A surface showing the bases of the cellules at their origin. 

 7 d, A portion of 7 a enlarged, 



7 c. A portion of surface of 7 6 enlarged. 



F'ig. 8. 428. 3. Ph^nopora knsiformis. (Pag. 48.) 



8 a. A single individual cf the natural size. 8 b. A portion of the same enlarged. 

 8 r. A fragment of stone having several specimens upon the surface. 



