INTRODUCTION. lix 



4. Genus Fistulipora. 



M'Coy, Ann. and Mag. of Nat. Hist., 2d series, vol. iii, p. 130, 1849. 

 Corallum with vesicular ccenenchyma ; thick walls and infundibuliform tabulae. 



Typ. sp., Fistulipora minor, M'Coy, loc. cit., figs, a, b. 



5. Genus Plasmopora. 



Milne Edw. and J. Hairne, Comptes rend., t. xxix, p. 262, 1849. 



Corallum free, sub-hemispheric, with a basal plate covered with an epitheca presenting 

 concentric folds. Calices immersed. Septa rudimentary. Tabula horizontal. Walls 

 thin. Ccenenchyma composed of large, vertical, radiate laminae, united by smaller hori- 

 zontal plates, and resembling much the costal ccenenchyma of the Astreidae. 



Typ. sp., Plasmopora petaliformis, nob. ; Porites petaliformis, Lonsdale, in Murchison, Sil. Syst., 

 pi. xvi, fig. 4. 



6. Genus Propora. 



Milne Edw. and J. Haime, Comptes rend., t. xxix, p. 262, 1849. 



Corallum differing from the preceding genus by the calices having exsert margins ; the 

 septa being more developed, and extending outwards so as to constitute small costae. 



Typ. sp., Propora tubulata, nob. ; Porites tubulata, Lonsdale, Sil. Syst., pi. xvi, figs. 3, 3°, 3 4 (cseteris 

 exclusis). 



7. Genus Axopora. 



Corallum composite, incrusting, and forming thin expansions, Avhich are often super- 

 posed. Ccenenchyma abundant, and forming irregular ridges between the calices, which 

 are small and deep. Septa rudimentary. Columella well developed, fasciculate, and 

 expanding at its passage through each of the tabulae. 



Typ. sp., Axopora piriformis, nob. ; Geodia pyriformis, Michelin, Icon., tab. xlvi, fig. 2. 



8. Genus Lobopora. 



Corallum having the same structure as in the preceding genus, but forming large, 

 thick, foliaceous expansions, the two surfaces of which are covered with calices. 



Typ. sp., Lobopora Solanderi, nob. ; Palmipora Solanderi, Michelin, op. cit., tab. xlv, fig. 9. 



