20 



TABULATE CORALS. 



VI. AULOPORID^:. This group is at present in such a totally 

 chaotic condition, that it is almost impossible to come to any 

 positive conclusion as to its true relationships or as to the 

 forms which it may contain. The genera Aulopora and 

 Cladochonus (^Pyrgia) were, as is well known, raised by 

 Milne-Edwards and Haime to the rank-of a distinct sub-order 

 of the Zoantharia the Z. Tubulosa (Pol. Foss. des Terr. Pal., 

 310, 1851) having been previously placed by them in the Al- 

 cyonaria. The alleged characters of the family are, that the 

 pyriform corallites are destitute of "tabulae/ 5 and possess nothing 

 but vertical striae representing the septa, while there are no 

 mural pores or connecting-tubes by which the visceral chambers 

 of contiguous corallites are placed in direct communication. 

 Taking Aulopora itself (fig. 8, A) as the type of this group, the 

 corallum is creeping, and attached by the whole of its lower 



Fig. 8. A, Portion of the corallum of Aulopora tubaformis, Goldf., from the Devonian of 

 the Eifel, of the natural size ; B, Two corallites of the same enlarged, showing septal 

 striae ; c, Cladochonus (Pyrgia) Michelini, E. and H. , Carboniferous, of the natural size ; 

 D, The same slightly enlarged, showing the interior of the calice. 



surface to some foreign body. The basal stolons divide and 

 send up the tubular or trumpet-shaped corallites, the terminal 

 portions of which are free and erect ; but in no case is the pro- 

 cess carried to the extent of producing a fasciculate corallum. 

 The tubes are for the most part not in contact with one 



