Prof. Nicholson mi Classification of " Tahulate Corals^ 99 



On the other hand, they present some conspicuous points of 

 resemblance to the Astrxida'- among the Zoantharia aporosa. 



V. SYEiNGOPORiDiE. — The type of this group is the Palaeo- 

 zoic genus, Syringopova, Goldf, in which the corallum is 

 fasciculate, and composed principally of long cylindrical 

 corallites which grow up side by side, rarely absolutely 

 touching one another, and are enclosed by strong and com- 

 pact walls. The visceral chambers of contiguous corallites 

 are placed in direct communication by means of hollow con- 

 necting-processes ; and there are usually marginal and rudi- 

 mentary septa. The tabulae are well developed, more or less 

 funnel-shaped, and sometimes giving rise to a central tube 

 in the median line of the visceral cavity. 



I cannot agree with the opinion of Dana, Hseckel, and 

 Zittel, that Syringopora and its allies should be placed among 

 the Alcyonaria, in the vicinity of the Eecent Tuhijpora. Nor 

 can I accept Dr Lindstrom's view that Syringopora is truly 

 a Eugose coral with af&nities to Litliostrotion and Dijphy- 

 pJiyllum. On the contrary, I am at present disposed to 

 believe that the real relationship of the Syringoporidce is 

 with the Favositidce, and that they should therefore find a 

 place — though a special one — in the division of the Zoan- 

 tharia perforata. Upon this view, the hollow connecting- 

 processes of Syringopora are the homologues of the " mural 

 pores" of the Favositidce; and the singular genus Syringo- 

 lites, Hinde, is a direct connecting link between these two 

 apparently dissimilar gTOups, since it possesses the mural 

 pores of the latter, conjoined with the infundibuliform 

 tabulae of the former. 



VI. AuLOPOPJDiE. — Taking Aulopora as the type of this 

 group, we find it to comprise singular parasitic corals which 

 grow upon the exterior of shells and corals in deposits of 

 Silurian, Devonian, and Carboniferous age. The corallum 

 consists of a network of creeping prostrate tubes, which send 

 up at intervals conical tubular corallites which have marginal 

 and rudimentary septa, and which, in some instances at any 

 rate, possess well-developed horizontal tabalse. The visceral 

 chambers of the corallites are not placed in communication 

 by means of mural pores or hollow connecting-processes. I 



