CLASSIFICATION. 17 



sites). The tabulae are usually well developed and complete, 

 but they are sometimes imperfect (Favosites hemispherica, Yand. 

 and Shum.) 



After an extended study of the minute structure of the 

 Fctvositida, I cannot doubt but that Professor Verrill and 

 Dr Lindstrom are right in referring all the Corals usually 

 included under this head to the Zoantharia Perforata. I 

 also fully recognise the many points of resemblance between 

 the Favositidcz and the Poritidee^ but I am not prepared to 

 follow the above-mentioned distinguished authorities in regard- 

 ing the present group as a mere sub-family of the Poritidce. 

 On the contrary, I think that the group Favositidce, as here 

 understood, embraces a large number of types (mostly Palaeo- 

 zoic), all of which are more or less allied to the Poritidce, and 

 some of which may perhaps be capable of final removal to the 

 latter family, but which really represent a series of separate 

 though allied groups. The reasons for this opinion will be 

 stated at greater length hereafter. I need only say here 

 that there is not the slightest ground, in my opinion, for 

 regarding the Favositida as anything but true Actinozoa, or 

 for removing them from the order of the Zoantharia. They 

 are not connected with the Heliolitidce by any links sufficiently 

 close to lead us to suppose that they are Alcyonaria ; and the 

 hypothesis of Dollfus (Comptes Rend., t. Ixxx., 1875), that 

 they are truly referable to the Polyzoa, hardly requires serious 

 refutation. 



IV. CoLUMNARiADyE. Under this head I provisionally place 

 a few Palaeozoic Corals, of which the only typical and un- 

 doubted examples known to me are C. alveolata, Goldf. 

 (Favistella stellata. Hall), and C. calicina, Nich. Both of these 

 have coralla composed of polygonal or subcylindrical corallites, 

 with well-developed compact walls, not penetrated by " mural 

 pores." The septa are lamellar, in two series, those of the 

 longer set extending nearly or quite to the axis of the visceral 

 chamber. There is no columella ; and though the corallites 

 may be to some extent disjunct, there is nothing of the nature 



B 



