CORALS OF THE LONDON CLAY. 37 



laterally. The six systems very distinct ; the primary septa much broader and taller than 

 the others ; the secondary ones smaller than those of the fourth order, which unite to those 

 of the fifth order opposite the almost rudimentary tertiary septa, and continuing to bend 

 towards the secondary ones, unite two by two along the inner edge of these, and so 

 constitute six laminae, that advance almost to the columella, and appear at first sight to be 

 prolongations of the secondary septa (fig. 3 a). The largest of these corallites are about 

 two lines in diameter at the calice, and project little more than a line above the common 

 mass ; the depth of the fossula is about one line and a quarter. The young individuals 

 very soon acquire all their septa. 



The genus Dendrophyllia has many representatives in the seas of the present period, 

 and in the upper tertiary formations, but the species here described is the only one that has 

 as yet been found in Eocene deposits, and is the oldest known, for the various fossil Corals 

 appertaining to remoter geological periods that have been referred to this generic division 

 by M. Michelin, and by some other authors, do not in reality belong to it. Dendrophyllia 

 dendrophjlloides differs from D. ramea, 1 D. Taurinensis, 2 and D. digitalis? by its irregular 

 gemmation ; from D. Cornigera, 4 * D. irregularis, 5 D. arnica, 6 and D. axifuga, by having 

 fewer septa (a cyclum less) ; and from D. gracilis 7 by not being arborescent. It resembles 

 most our Den drop //gllia Cecilliana, but this last-mentioned species, which lives in the Chinese 

 seas, is sufficiently characterised by its broad costa?, formed by double or triple rows of 

 small granulations, and by its large prominent columella. 



This fossil Coral is found at Bracklesham Bay, and has been communicated to us by 

 Mr. Bowerbank, Mr. Dixon, and Mr. Frederick Edwards. 



4. Genus Stereopsammia (p. liii). 

 Stereopsammta humilis. Tab. V, figs. 4, 4 a, 4 b. 



Corallum composite, incrusting, glomerulate, remaining low, and increasing by means 

 of an irregular basal gemmation. Corallites crowded together, cylindrical, short, united 

 by the basis, and free down at least two thirds of their length from the calice. The costal 

 tissue which unites them at their basis, is in general but little developed, and does not 

 deserve the name of ccenenchyma. Gemmation seldom takes place laterally ; sometimes, 

 however, reproductive buds are formed on the side of a parent corallite at a certain distance 

 from its basis, and will thus produce a slight appearance of ramification. Costa very 



1 Madrepora ramea, Solander and Ellis, Zooph., tab. xxxviii. 



2 Michelin, op. cit., tab. x, fig. 8. 



3 Michelin, loc. cit., tab. x, fig. 10; and tab. lxxiv, fig. 4. 

 1 Esper, Pflanz. Madrep., tab. x. 



5 Michelin, op. cit., tab. lxxiv, fig. 3. 



6 Milne Edwards and J. Haime, Ann. des Sc. Nat., 3 me serie, vol. x, tab. i, fig. 9. 



7 Milne Edwards and J. Haime, loc. cit., fig. 13. 



