THE BED CHALK OF HUNSTANTOjST. 481 



Genus Reptomflticava, d'Orb. 



1826. Ceriopora (pars), Goldfuss ; Blainville. 



1852. Rej)tomulticava, d'Orbigny, Terr. Cret. p. 1032. 



Under the above generic name d'Orbigny places a considerable 

 number of fossil forms. The colony is fixed by the whole of the 

 inferior surface, and the general character of the superior face 

 would be sufficient in itself to characterize species as Ceriopora, 

 Goldfuss, previous to the rigid separation of that group by Blain- 

 ville and d'Orbigny. Many of the flattened' discoid MontleullporcE 

 of the older rocks are to some extent similar to these Cretaceous 

 forms. 



83. .Keptomulticava simplex (?), d'Orb. 



1852. Eeptomulticava simplex, d'Orb. Terr. Cret. v. p. 1041, 

 pi. 793. fig. 5. 



The R. simplex^ d'Orb., resembles, by its flattened figure, the 

 Red-Chalk fossil placed here. The zoarium is simple,, or disc-like, 

 without any elaborate detail other than the small openings in the 

 surface, which are very fine and characteristic, as in figs. 5 and 8 

 of plate 793, Terr. Cret. 



Habitat. On Terehratula hipUcata. Fossil No. 32. 



Horizon. Red Chalk, Hunstanton. 



34. Reptomtjlticava collis (?), d'Orb. 



1852. Reptomulticava collis, d'Orb. Terr. Cret. v. p. 1036, pi. 792. 

 figs. 1-3. 



1854. Reptomulticava collis (?), d^Orh.; Morris, Cat. Brit. Eossils, 

 p. 128. 



On several fossils of the Red Chalk are small colonies of a species 

 similar to the forms described and figured by d'Orbigny as Repto- 

 iiiulticava collis. The general character and markings of the sur- 

 face of the little dome-like zoarium are more like the species which 

 d'Orbigny calls R. cupula, d'Orb., pi. 792, fig, 10 ; but this form is 

 only partially attached at the base (figs. 8, 9), whereas the Red- 

 Chalk examples are wholly attached. I have met with several 

 examples of these little forms, but I am unable to follow d'Orbigny 

 in establishing, even suggestively, other than these two species. 

 Even those indicated vary slightly in their colonial growths. 



Habitat. On Terehratula, Inoceramus, Belemnites. Fossils JN^os. 

 33 and 36. 



Horizon. Red Chalk, Hunstanton. Neocomian, Fontenvoy 

 ((VOrb.) 



Genus Zonopoea, d'Orb. 



1847. Zonop)ora, d'Orb.; 1851. Plethopora (pars), Hagenow ; 

 1852. Zonopora (Fam. Caveida^, d'Orb.), Terr. Cret. v. p. 928. 



D'Orbigny, in his 5th family Caveidce (Terr. Cret. p. 922), has 

 brought together no fewer than twenty-seven genera, all of which, 

 to say the least, are peculiar and characteristic. The author includes 



