1826;^' .- ' Geological Society. 301 



. President.— 3 o\in Bostock, MD. FRS. 



Vice-Presidents. — Sir Alexander Crichton, MD. FRS. and 

 LS. Hon. Memb. Imp. Acad. St. Petersburgh ; Rev. W. D, 

 Conybeare, FRS. ; William Henry Fitton, MD. FRS. ; and 

 Charles Stokes, Esq. FRA. and LS. 



Secretaries. — W. J. Broderip, Esq. ; R. J. Murchison, Esq. ; 

 and Thomas Webster, Esq. 



Foreign Secretary. — Henry Heuland, Esq. 



Treasurer. — John Taylor, Esq. 



Council. — Arthur Aikin, Esq. FLS.; Henry Thomas De la 

 Beche, Esq. FRS. and LS. ; J. E. Bicheno, Esq. Sec. LS. ; 

 Henry Thomas Colebrooke, Esq. FRSL. and E. FL. and Asiat, 

 Soc. ; Sir Charles Henry Colvil ; George Bellas Greenough, 

 Esq. FR. and LS. ; Sir Charles Lemon, Bart. FRS. ; Armand 

 Levi, Esq. ; Charles Lyell, Esq. FR. and LS. ; William Hasle- 

 dine Pepys, Esq. FRS. LS. and HS. ; George Poulett Scrope, 

 Esq.; J. F. Vandercom, Esq.; and Henry Warburton, Esq. 

 FRS. 



March 3. — The reading of Sir A. Crichton's paper, on the 

 Taunus Mountains in Nassau, was concluded. 



The great mountain groups forming the Taunus are portions 

 of that vast chain which crosses the Rhine to Valenciennes ; 

 and in the duchy of Nassau they are composed of transition and 

 trap rocks : they here separate into two ranges, nearly at right 

 angles to each other. The southern chain lies on the north of 

 Mayence and Frankfort, and its highest point is the Feldberg, 

 2600 feet above the level of the Mayne. The northern chain 

 includes the Westervald, celebrated for its brown-coal. The 

 strata of the southern face of the former chain consist of talc 

 and quartz-slate dipping north-west; whilst those of the north- 

 ern face are ofgrauwacke and clay-slate, inclining upward south- 

 east. The summit is a decomposing quartz-rock, containing 

 talc and iron, the sides and base of the mountain being formed 

 of talc and slate. The baths of Schlangenbad are surrounded 

 by slaty quartz: quartz-conglomerates occur near the foot of the 

 southern chain ; where also a thick bed of sandstone, resembling 

 our new red sandstone, rests upon the calcareous deposits of 

 the valley of the Mayne, quarries of which are seen at Wisbaden. 



The valley of the Mayne, which is interposed between the 

 northern and southern chains, is chiefly occupied by low hills 

 of coarse shelly limestone, analogous to the upper freshwater 

 formation of Paris, and quarries of it occur near Wisbaden and 

 Hockheim : Paludina and Modioli abound in it. At Hockheim 

 the beds are much dislocated, and at Wisbaden fossil bones are 

 found, the teeth accompanying which refer them to animals 

 allied to the Lophiodon tapiroides, and to the Suniatran Tapir. 

 These calcareous deposits are only two hundred feet above the 

 level of the Mayne, and tUey are perforated in many places by 



