lviii BRITISH FOSSIL CORALS. 



instead of occupying only the one or two loculi. It is also to be remembered that the 

 septal apparatus, although more or less rudimentary, has the same general mode of 

 arrangement as in the preceding sub-orders, and never presents the crucial character which 

 we shall find in Zoantharia rugosa. 



This section comprises four families : Favositidae, Milleporidse, Seriatoporidae, and 

 Thecidas. 



Family VIII. 

 MILLEPORIDSE. 



Corallum principally composed of a very abundant coenenchyma, distinct from the 

 walls of the corallites, and of a tubular or cellular structure. Septa not numerous ; 

 tabulae numerous, and well formed. 



1. Genus Millepora. 



(Pars) Lamarck, Syst. des An. sans Vert., p. 373, 1801 ; Palmipora, Blainville, Diet, des Sc. Nat., t. Ix, 



p. 356, 1830. 



Corallum of various forms, but more or less foliaceous. Comenchyma extremely 

 abundant, of an irregular subtubular structure. Calices of very different dimensions in 

 the same corallum. No distinct septa. Tabidce horizontal. 



Typ. sp., Millepora alcicornis, Lamarck, loc. cit. ; Milne Edw., Atlas du Regne Anim. de Cuvier, 

 Zooph., tab. lxxxix, fig. 1. 



2. Genus Heliopora. 



(Pars) Blainville, Diet, des Sc. Nat., vol. Ix, p. 357, 1830; Dana, Zooph., p. 539, 1846. 



Corallum lobulate, somewhat massive, and differing from Millepora by the regular 

 tubular structure of the coenenchyma, and the existence of small but distinct septa. 



Typ. sp., Heliopora ccerulea, Blainville, loc. cit., p. 357. 



3. Genus Heliolites. 



Dana, Zooph., p. 541, 1846 ; Palceopora, M'Coy, Ann. and Mag. of Nat. Hist., 2d series, vol. hi, p. 129, 

 1849; Geoporites, D'Orbigny, Prodr. de Palseont. stratif. Univers., t. i, p. 49, 1849. 



Corallum sub-globose. Ccenenchyma regularly tubular. Septal radii advancing 

 almost to the centre of the visceral chamber on the upper surface of the tabulas, which 

 are horizontal. 



Typ. sp., Heliolites pyriformis, Dana, loc. cit., p. 542 ; Heliolite pyriforme, etc., Gucttard, Mem. snr 

 les Sc. et les Arts, vol. hi, pi. xxh, figs. 13, 14. 



