6 HiCKSON, Neiv Octoradiate Coral, Pyrophyllia injiata. 



named genus ; but its species has a large septum which 

 is a very marked Rugose peculiarity, and the replacement 

 of such septa by depressions or fossulae is common." 

 But PyyopJiyllia has neither a fossula nor a large septum 

 and is therefore less closely related to CyatJiaxonia 

 than Guyiiia is. There is another point of difference 

 between them which may be of less importance than 

 appears to be when it is set down in words. Giiynia is 

 said by Duncan to have no endotheca, according to my 

 account Pyrophyllia has an endotheca below the true 

 calyx. The absence of endotheca separates Gnynia from 

 the Cyathophyllidae and the presence of it would ac- 

 cording to the definitions separate Pyrophyllia from the 

 Cyathaxoniidae. According to Duncan the endotheca is 



composed of " thin plate-like structures which unite 



septa, close the loculi and enable the coral to grow in 

 height and strength and limit the growth downwards of 

 mesenteries and soft parts." If we accept this as the 

 definition of endotheca there can be no doubt of its 

 presence in Pyrophyllia, but some doubt may be ex- 

 pressed whether, judging from the figures and description, 

 there is not something corresponding with the endotheca 

 in Guynia also. 



I am inclined however to agree with Gardiner* that 

 this character may not be one of any great importance, 

 and I regard Guytiia and Pyrophyllia as members of the 

 same family and probably closely related to one another. 

 The very regular radiate arrangement of the septa in 

 Pyrophyllia and their very definite and invariable number, 

 separate it very distinctly from both Giiynia and Haplo- 

 phyllia as a distinct genus, but by the same characters it 

 is also distinguished from their supposed palaeozoic allies. 



^' Turbinoliid corals (jf S. Africa, 1904. Marine Iiiz^afiga/ioiis in 

 S. A/rii-a, \u\. III. 



