276 Rev. A. Irving — On the Permian and Trias. 



hill-country, about the northern half of the Vosges, between Luxem- 

 burg and Treves, and in parts of the Eifel) a very different character, 

 sandstones and marls (containing Muschelkalk fossils) replacing in 

 some places {e.g. about Saarbriick) the limestone, while the whole 

 formation becomes greatly attenuated, until at last [e.g. on the 

 Attert) the thickness of the Muschelkalk has dwindled to four feet 

 and even to a foot. " This extraordinarily feeble development of the 

 Muschelkalk prepares us for the English facies of the Trias, where 

 the Keuper lies directly upou the Buntev Sandstone." (Credner). 



PalcBontological Evidence. 



In recent discussions on this subject there would appear to be 

 sometimes a want of sympathy between the physical geologist and 

 the palaeontologist, and a tendency on the part of the former to 

 attach too slight a value to the evidence furnished by the remains of 

 the fauna and flora of the Permian and Triassic ages. Conclusions 

 as to the true relation of these two systems to one another must not 

 be drawn from physical evidence alone, as it is furnished in particular 

 and limited areas. There is no doubt that if such evidence were 

 admitted as of primary value, a great deal might be said to establish 

 a continuity between the Permian and Trias, and to justify the 

 grouping of them both in one system. This was pointed out some 

 years ago by the late Prof. Phillips with reference to the Worcester- 

 shire and Warwickshire districts,^ and a good deal has been written 

 since then on the succession of the strata as it is presented to us in 

 the north-eastern and north-western areas of England, where, as we 

 have shown, the break in the one area between the Permian and the 

 Trias is not nearly so great as was at one time supposed, while in 

 the other area there is no physical break at all, in one portion at 

 least. We may go further, and point to the succession of the same 

 great group of strata as it occurs in Germany. In that country, 

 as pointed out long ago by Murchison,^ " no physical dismember- 

 ment has been observed, which separates the strata accumulated at 

 the close of the Permian period from those formed in the earliest 

 period of the Trias, the summit of the one being everywhere con- 

 formable to the base of the other." 



The excellent monograph of King on the fauna of the British 

 Permians is too well known to need more than a passing mention 

 here. It may, however, be useful to add a few remarks and 

 generalizations from so high an authority as Credner.^ 



The flora of the Byas, he points out, is closely allied to the Car- 

 boniferous flora, and represents the latest remains and traces of a 

 Tanishing Palfeozoic world, consisting mostly of marsh- and shore- 

 forms (mainly confined to the Rothliegende), with Caulerpites repre- 

 senting marine forms. Though poor in forms of life, both flora and 

 fauna have a definite Palseozoic ' character,' and are closely allied to 

 those of Carboniferous times. The Post-Carboniferous flora consists 

 (with the exception of a few lower forms) of Cycads, Conifers, 



1 Geology of Oxford and the Valley of the Thames, chap. viii. 



2 MurcMson and Morris, in Q.J.G.S., vol. xi. ^ M. de Geol. pp. 466, et seq. 



