COEALS AND COEALLIFOEM TYPES. 43 



Fam. 5. Si/ringo/ioridœ : — Corallites tubular, imperforate, eouuected by .short trans- 

 verse processes or by lateral expansions. Tabulœ, funnel-shaped : 



Synngo])ora, Gold., Dev., Garb. 

 Hameophyllum, Bill., Dev. 



§ 3. Celi.ulata. 



This section, like the last, comprises a .series of coralloidal forms of very doubtful 

 position, but connected with the Hydro-Coralla generally by the presence of niimerous 

 tabulae ; and in one of the two families, into which they are subdivided, by distinct 

 septa, or " pseudo-septa." They are made up of capilliform or narrow tubirlar coralli- 

 tes, traversed by septa, and connected by cœneuchyme, in itself composed of minute, 

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

 corallites represent the oscula. Some have been given to the Bryozoa. Others, from their 

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

 it seems better to leave them among the Hydko-Coralla until more certain evidence 

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

 genera as follows : 



Fam. 1. Fisluliporidce : — Corallum compovrnd, composed of minute corallites with 

 surrounding capilliform cœnenchyme ; both tabulated, but without septa. 



Fistulipora, McCoy, Sil., Dev. 



Callopora, Hall (scarcely diflFering from Fistulipora), Sil., Dev. 



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

 a cellular or finely tubular cœnenchyme ; both tabulated ; the corallites showing twelve 

 short septa or pseudo-septa around their inner margin. 



Heliolites, Dana, Sil., Dev. 

 Lyellia, 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 tabulte and septa. 

 The tabulae 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. Favistellidœ : — 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, Goldf., Lr. Sil. 

 Favistella, Dana, Sil. 



