JDr. J. TT. Daicson — Carboniferous Batrachia. 
77 
beds were deposited ; in age between tbe Jurassic and Cretaceous 
periods ; and belonging to the S.W.-N.E. series. 
2. Tbe second, also synclinal, is the depression of the Somme ; in 
age, between the Wealden and Neocomian; belonging to the S.E.- 
N.W. series. 
3. The third, also S.E.-N.W., is the first indication of tlre 
elevation of the Boulonnais and the Weald, and took place between 
the Gault and Glauconitic Chalk periods. 
4. The fourth is the S.W.-N.E. anticlinal ridge from Ferte- 
Bernard to Brunelles. 
5. The three S.E.-N.W. folds of the Perche hills follow next, 
posterior to the Chalk with Inoceramus labiatus, anterior probably to 
that with Terebratella Bourgeoisii, but at all events of Turoniau age. 
6. The above-named crumplings doubtless acted on other parts of 
the basin besides those named, but it was especially after the 
deposition of the Chalk with Micraster cor-anguinum and before that 
of the Chalk with Belemnitella, that the S.E.-N.W. elevations of the 
Seine, of Bray, Bresle, and Artois were clearly defined. 
7. The S.W.-N.E. fold of Pressagny-rOrgueilleux to Breteuil, also 
anterior to the Chalk with Belemnitella, was coincident with an 
upheaval of N.W. France, and the formation in the north-east, in 
Flanders, of a channel, apparently the only one, connecting the Paris 
Basin with the North Sea. 
8. Finally, between the periods of the Chalk with Belemnitella 
mucronata, and the Pisolitic Chalk, an increase of elevation took 
place in the S.W.-N.E. axes of Bray and the Seine. 
The lateral pressures which have caused these two Systems of 
folds seem generallv to have acted altemately, and so far from having 
formed them at once, appear to have acted through successive epochs. 
The S.W.-N.E. system showed itself first ; butas faras the actual con- 
figuration of the ground is concerned, the S.E.-N.W. series exercised 
the more considerable influence, inasmuch as its action was prolonged 
to the close of the Tertiary deposits of the Paris Basin, destroying or 
at least obliterating the effects of the perpendicular folding. 
II. — 0> T a Becent Discovery of Carboniferous Batrachians in 
Nova Scotia. By J. W. Dawson, LL.D., F.E.S. (American 
Journal of Science and Arts, vol. xii., Dec. 1876.) 
T HE erect Sigillari® inclosed in the sandstone overlying coal- 
group 15 of Section XY. Division 4, of the South Joggins 
section, have already furnished Principal Dawson with numerous 
remains of the reptilia of the Coal Period. The contents of anotlier 
of these hollow stems have recently been investigated by him with 
great success. 
Thirteen skeletons, representing six species, were brought to light, 
besides several Millipedes and Shells of Pupa vetusta. These 
remains enable Prof. Dawson to give fuller descriptions than hitherto 
of the genera Hylerpeton, JDendrerpeton, and Hylonomus, and to add 
two new species to the first-named genus, viz. — Hylerpeton longi- 
dentatus, and H. curtidentatus. 
