﻿Dr. J. W. DaiDSon — Carboniferous Batrachia. 77 



beds were deposited ; in age between the Jurassic and Cretaceous 

 periods ; and belonging to the S.W.-N.E. series. 



2. The second, also sj^nclinal, is the depression of the Somme ; in 

 age, between the Wealden and Neocomiah; belonging to the S.E.- 

 N.W. series. 



3. The third, also S.E.-N.W., is the first indication of the 

 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 Boiirgeoisii, but at all events of Turonian 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 Micr aster 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 

 miicronata, 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 generally to have acted alternately, 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 ; but as far as 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. — On a Eecent Discovery of Carbonifekous Batkachians in 

 Nova Scotia. By J. W. Dawson, LL.D., F.K.S. (American 

 Journal of Science and Arts, vol. xii., Dec. 1876.) 



THE erect Sigillarife inclosed in the sandstone overlying coal- 

 group 15 of Section XV. 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 another 

 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 Piqm vetusta. These 

 remains enable Prof. Dawson to give fuller descriptions than hitherto 

 of the genera Hylerpeton, Dendrerpeton, and Hylonomns, and to add 

 two new species to the first-named genus, viz. — Hylerpeton longi- 

 dentatus, and M. curtidentatus. 



