EXPLANATION OF PLATE XV. 



Fijjs. 1 - t. Gonivpurafrulicosa, S.-Kaiit. 1 — Coralluin with a purtiou of 

 the polyps extended, natural size. 2 and 3 — Horizontal and 

 profile aspects of a siuy;le polype, enlarged '2 diameters, i — 

 Single oaliele of ooralhuu enlarged. 



Figs 5-8. Alreupora ipoiujiusa, Dana. o — C'oralliuii with polypes ex- 

 tended, natural size. G and 7 — Horizontal and profile aspects 

 of a single polype, enlarged 2 diameters. 8— Superficial 

 aspect of a few adjacent ealicles, showing spinous septal 

 olonieuts, enlarged. 



