xlviii BRITISH FOSSIL CORALS. 



9. Genus Halomitra. 



Dana, Zooph., p. 311, 1846. 



Corallum composite, differing from the preceding genus by its very long and numerous 

 septa. 



Typ. sp., Halomitra pileus, Dana, loc. cit., p. 311 ; Fungia pileus, Lamarck, Hist, des An. sans Vert., 

 t. ii, p. 237- 



10. Genus Podobacia. 



Milne Edw. and J. Haime, loc. cit., p'. 71, 1849. 

 Corallum composite, cyathiform, and adherent by its basis. Calices as in Halomitra. 



Typ. sp., Podobacia cyathoides, nob.; Agaricia cyathoides, Valenciennes MSS., in the Gallery of the 

 Paris Museum. 



11. Genus Lith actinia. 



Lesson, Illustr. Zool., 1833. 



Corallum composite, free. Calices of one sort only, and not radiate. Septa short, 

 and separated by very thin, transverse laminse, which appear to be analogous to columella. 



Typ. sp., Lithactinia novcehybernice, Lesson, loc. cit., vi, figs. 1, 2. 



12. Genus Polyphyllia. 



Quoy and Gaimard, Voy. de 1' Astrolabe, Zooph., p. 184, 1833. 



Corallum composite, free, and having calices of two sorts ; the central ones sub-radiate, 

 and arranged in a line. 



Typ. sp., Polyphyllia pelvis, Quoy and Gaimard, loc. cit., pi. xx, figs. 8 — 10. 



13. Genus Zoopiltjs. 



Dana, Zooph., p. 318, 1846. 



Corallum composite. Septa of two sorts ; the large ones radiately prolonged quite to 

 the margin ; the intermediate much smaller, and those only interrupted by the calicular 

 fossulse or oririms. 



Typ, sp., Zoopilus echinatus, Dana, op. cit., p. 319. 



Third Tribe- LOPHOSERIN^E. 

 Plate (or basal wall) not perforate nor echinulate. No epitheca. 



