FAMILIES AT^D GENERA OF THE MADEEPOEAHIA. 131 



around ,a very large median calicle, which has very mimerous 

 septal orders, the calicles becoming polygonal and deep at the 

 centre. Epitheca very slight ; wall very thin and almost rudi- 

 mentary, but developed so as to give a distinct simple line of 

 separation to the calicles on the surface, often interrupted ; seen 

 in section in a very rudimentary state separating the calicinal 

 centres. Costse very distinct, thin, and finely denticulate. 

 Septa often confluent and continuous, from centre to centre, in 

 the line of union between adjoining calicles, very thin and close, 

 finely toothed above, and having the teeth subequal or slightly 

 larger near the centre. Endothecal dissepiments vesicular, very 

 abundantly developed, leaving but a very small portion of the 

 septa free exteriorly ; seen in transverse section forming nearly 

 concentric lines, and more or less complete tabulae at the 

 centre. A false columella present, seen exteriorly to be formed 

 by the trabeculate and vermiform nature of the innermost upper 

 part of the septa, entirely or almost absent in transverse section, 

 where the septa are seen to meet almost at a point. 

 Distribution. — Recent. Torres Straits. 



The next and last genus of this family is placed at the close of 

 it provisionally. It will not conform to any Alliance, although 

 it has some Latimseandroid characters of growth. 



Group-genus Dictyophyllia, Blainville. 

 Genus Dictyophtllia, Blainville, Man. d'Actin. p. 360, pi. 53. 

 fig. 4 ; Diet, des Sci. Nat. t. Ix. p. 523 (1830), amended. 

 Colony incrusting, covering considerable space. Surface sub- 

 plane. Corallites low, separated by very narrow grooves at the 

 calicular surface, variable in size. Calices more or less polygonal 

 or circular, or long, nearly or quite straight, narrow, looking like 

 a series with perfectly indistinct centres. In a polygonal calice 

 (one of a bud) are numerous subequal, close, short septa pro- 

 jecting from the wall a little way inwards, and within these, 

 towards the calicular centre and occupying a large space, is a 

 columella — a mass of trabeculse, reticulate and slightly convex ; 

 trabeculse connected, here and there, by cross bars. The long 

 calices show the same structures as the others— a wall with short 

 subapical septa projectiDg a little, and a large long axial mass of 

 trabeculee — the columella. The columella appears to rise from a 

 flat floor, which is presumably the base of the colony. Costse 

 absent. Calicular walls separated. 



9* 



