326 Mr. Weaver on the [May, 



" Generally speaking, the rothliegende seems the more dis- 

 posed to receive foreign ingredients into its composition, as well 

 as beds, the nearer it approaches to the fundamental rocks upon 

 which it reposes. And it is not to be denied that it possesses 

 many points of agreement with transition tracts; so much so, that 

 some geologists are disposed to rank it rather with the transition 

 series, and to commence the floetz series only with the rocks 

 peculiarly belonging to the bituminous or cupriferous marl 

 shale " * (of which the weissliegende, or new conglomerate, is the 

 first or lowest member). 



The connexion of the rothliegende with transition grey wacke 

 and clayslate tracts, is exemplified by a reference to the districts 

 of Mannsfeld, Sangerhausen, and Stollberg, where it reposes 

 upon, and partly graduates into them. 



Its connexion with porphyry (trap also occurring in the asso- 

 ciation), is stated to be particularly well exhibited in the Forest 

 of Thuringia, the two formations not only alternating with, but 

 appearing in a manner diffused in each other ; e. g. in the north- 

 ern declivity of the Schneekopf, and again extending from the 

 Grossen Buche into the Schniuckengraben in the same moun- 

 tain. Its intimate alliance with porphyry is shown also in 

 Mannsfeld. — (See Annals of Philosophy, Aug. 1822, p. 87.) 



In all these cases, the ingredients which compose the roth- 

 liegende are said to vary more or less according to the constitu- 

 tion of the transition or primary tracts upon which it reposes. — 

 (See Freiesleben, vol. i. p. 32 — 34, and p. 43 — 46 ; and also vol. 

 iv. p. 67—99.) 



Both relative position and physical characters, therefore, 

 prove that the rothliegende constitutes, in its lotvest position, the 

 fundamental portion of the series, or what is designated in 

 England as the old red sandstone. 



2. The same inference is to be drawn, from considering the 

 connexion of the rothliegende with the coal formation. 



On this subject, Freiesleben (see p. 170 — 172 of vol. iv.) 

 adverts, in the first place, to the distinctions formerly made in 

 Germany respecting the relation of the coal formation to the 

 rothliegende ; some writers having considered a portion only of 

 the coal formation as included in the rothliegende, while others 

 incorporated the whole of the coal formation with the rothlie- 

 gende ; thus constituting, instead of one group with two divisions, 

 one simple unbroken series. As an exemplification of the latter 

 mode of considering the subject, he produces the arrangement 

 of Karsten, who gives the following beds as a type of the general 

 series, taken in an ascending order : 



t "See Von Hoff in Leonhard's Taschenbuch. Jahrgang. viii." 



