MADREPORARIA OF THE BOULONNAIS. 699 
1871*. While investigating the present collection I haye met with 
great assistance from the comparison of a very considerable number 
of species from the Corallian of the Haute-Sadne, France, for which 
I am especially indebted to M. de Fromentel. These and a good 
number of species from Nattheim have rendered me good service. 
The conclusions of Dr. Lycett, based chiefly on the study of the 
Testacea, relative to the general paleontological uniformity which 
exists throughout the whole of the Great Oolite of the Cotteswold 
Hills, are considerably strengthened by my own observations on the 
coralline beds of that division of the Oolites.. In my paper on the 
Great-Oolite corals of the counties of Oxford and Gloucester, I 
have shown that these successive coral-beds are merely a repetition 
of each other. That conclusion, however, although not at that time 
inaccurate, so far as the district mentioned is concerned, now 
demands some modification. Excepting for the species described 
under the name of Bathycenia solidat, the precise stratigraphical 
position of which is not known, it would have been quite proper to 
have restricted the genus Bathycena to the Cornbrash. And in 
fact, as I shall here show, such a conclusion would have been 
inevitable if the Great-Oolite corals of the Boulonnais had been 
brought into immediate comparison with those from the corre- 
sponding deposits of this country. Not only is the genus Bathycenia 
in the Boulogne Oolite peculiar to the Cornbrash, but the new and 
allied genus Drscocenia is also confined to it. Again, so far as present 
information goes, the genus Scyphocewima is confined to the lower 
part of the Great Oolite. 
The Great Oolite of the district now under consideration, resting 
immediately on Paleozoic rocks, precludes the existence there of any 
beds corresponding in age to the Inferior Oolite; but under the 
impression that some obscure Madreporarian form might have escaped 
observers, | looked with especial solicitude for some species which 
would, like the corals in the bottom of the Lias of the Glamorgan- 
shire coast, indicate the existence of a coralliferous sea of earlier 
date than that in which the Great Oolite was deposited. But not a 
trace appears of a species which could with certainty be identified 
as being proper to the Inferior Oolite. On the contrary, the species 
which have been met with near the bottom of the Great Oolite have 
a facies which would seem to assimilate them more or less nearly to 
those of our Cornbrash. 
The following generalized section has been prepared by M. Rigaux, 
and the specimens forwarded by him having the locality attached to 
them, the several species, when determined, have been placed by me 
opposite their respective localities. A satisfactory stratigraphical 
distribution has been thus obtained, and it is interesting to observe 
the general correspondence which exists between the range in time 
of the Boulonnais and English species :— 
* Tyans. Zool. Soe. vol. viii. pt. 5, p. 303, 1873, read May 16th, 1871. 
t Quart. Journ. Geol. Soc. vol. xxxix. p. 177. 
