CORALS AND CORALLIFOEM TYPES. 48 



Fam. '). S//ringo/>orid(C : — Corallites tubular, imperforate, coniiocted by short trnns- 

 vprse processes or by lateral expansions. Tabuhe, funnel-shaped : 



Sf/ri)/i:^oporn, Gold., ]")ev., Carb. 

 Hdinifo/iliijllum, Bill., Dev. 



§ ^. CELTiULATA. 



Tliis settion. like the last, comprises a series of coralloidal forms of very doubtful 

 l^osition, but conneeted with the Hydro-Coralla irenerally by the presence of numerous 

 tabuhe; and in one of the two families, into whi(^h they are subdivided, by distinct 

 septa, or " ps<'udo-septa." They are made up of capilliform or narrow tubular coralli- 

 ti's, traversed by septa, and connected by ccenenchyme, in itself composed of minute, 

 tabulated lubes, the whole .somewhat resembling the surface of a sponge in which the 

 ( orallites represent the oscula. Some have been given to the Bryozon. Others, from their 

 supposed relations to the modern Heliopwa, have been referred to the Alcyonaria ; but 

 it seems better to leave them among the HyuRO-CoRAT,iiA until more certain evidence 

 is obtained of their true affinities. They may be subdivided into two families, with 

 gejiera as follows : 



Fam. 1. Fistuliporidce : — Corallum compound, composed of minute corallites with 

 surrounding capilliform cconenchyme ; both tabulated, but without septa. 



Fistulipora, McCoy, Sil., Dev. 



Cullopora, Hall (scarcely differing from Fistulipnra), Sil., Dev. 



Fam. 2. Heliolitidce : — Corallum compound, composed of small corallites separated by 

 a < ellular or finely tubular ca-nenchyme ; both tabulated ; the corallites showing twelve 

 short septa or pseudo-septa around their inner margin. 



Heliolites, Dana, Sil., Dev. 

 Lijellia, E. & H., Sil. 

 Plasmopora, E. & H., Sil. 

 Thecia, E. & H , Sil. 



§ 4. Tabulo-Stellata. 



The corals of this section are characterized by the presence of both tabula3 and septa. 

 The tabulce extend in typical examples entirely across the corallite-cell, but indications 

 of an outer area of vesicular tissue are occasionally observable. The septa are marginal 

 or short in some cases, although always distinctly developed. In other cases they extend 

 into the centre of the cell, and form by their union a twisted pseudo-columella. The 

 typical representatives form three families, as in the annexed tabular distribution : 



Fam. 1. FavistelHdte : — Corallum compound, with hexagonal or polygonal corallites 

 in close juxtaposition, much resembling Favosites ; but walls imperforate, and distinct 

 septa (short or long) always present. 



Columnaria, Groldf., Lr. Sil. 



Favistella, Dana, Sil. • 



