198 



FOSSIL ACTINOZOA. 



pom (fig. 83), and Rhodarcea. The genus Alveopora is one 

 of special interest, as its corallites are provided with well- 

 developed tabulae (fig. 

 83, A). The closely- 

 allied Favositipora of 

 Mr Saville Kent, found 

 both in the Devonian 

 and in existing seas, 

 not only possesses ta- 

 bulae, but is in other 

 respects extremely sim- 

 ilar to some of the Fa- 

 vositidce. It seems, in 

 fact, impossible to doubt 

 that the place of the 

 large and principally 

 Palaeozoic family just 

 mentioned is in the 



vicinity of the Poritidce, though, in deference to long re- 

 ceived and still current systems, we shall here retain it in 

 the provisional group of the " Tabulate Corals." 



Fig. 84. Fragment of Microsolena (Dendrarcea) 

 ramosa, and three of the calices of the same, enlarged. 

 Jurassic. 



III. TABULATA. 



The group of the " Tabulate Corals," as founded by Milne- 

 Edwards and Haime, included a large number of corals, in 

 many respects very unlike each other, but characterised by 

 the rudimentary condition or absence of the septa, conjoined 

 with the presence of well - developed tabulce dividing the 

 visceral chamber into so many distinct stories. It is now 

 known, however, that the presence of tabulae cannot be re- 

 garded as a point of any great classificatory value ; and the 

 researches of naturalists, and especially of Verrill and 

 Moseley, into the structure of living forms have shown that 

 the various recent " Tabulate Corals " are of the most diverse 

 nature. Thus it has been shown that Pocillopora (and prob- 

 ably Seriatopora also) is a true Aporose Zoantharian. On 

 the other hand, the living Heliopora is not a Zoantharian at 

 all, but a genuine Alcyonarian ; and this discovery removes 



