22 GEOLOGICAL MEMOIRS. 



granite and schist, through which it has broken, and, as accessory 

 minerals, rutile, copper-pyrites, magnetic oxide of iron, apatite, as- 

 bestos, &c. 



(5.) Trap-dykes, varying considerably in character from one 

 another, apparently according to the nature of the rocks through 

 which they have passed — generally small, but occasionally, as at 

 Dybvig, above 20 feet wide. These are considered to be of the 

 same age as those mentioned in the commencement of this notice. 



To this class also belong the zircon-syenite and augitic porphyry 

 previously noticed. [D. F.] 



On the Triassic Strata of the Vorarlberg. By Baron 



RlCHTHOFEN. 



[Proceed. Imp. Geol. Instit. Vienna, August 1857.] 

 Baron Richthofen, who has made the triassic and liassic beds in 

 the Vorarlberg* and Lichtenstein the object of special investigation, 

 finds that the northern limit of the crystalline schists runs from the 

 Arlberg along the Klosterthal, as far as Dalaas ; it then turns to the 

 south-west, crosses the Montaron near Schrums, and passes into the 

 Swiss Prattigau near Weiss-blatten on Mount Rheticon. This line 

 and another running in a nearly parallel direction, from Feldkirch 

 to the upper Iller Valley, are the boundaries of the triassic and liassic 

 regions. The Trias and Lias are wanting to the north of this, and 

 do not continue westward into the Helvetian territory. 



The succession of strata, in ascending order, as clearly exposed to 

 view in the Klosterthal, is — 1. Verrucano and the Werfen-strata ; 2. 

 Guttenstein-limestone ; 3. Marls with Bactryllium Schmidii and 

 Halobia Lommeli ; 4. Dolomite and porous limestones, passing into 

 pumice-like " Rauchwackes ;" 5. Main dolomite, in enormous 

 development; 6. Koessen-strata ; 7. Dachstein-limes tones ; 8. Ad- 

 neth-strata and spotted marls, both of these forming some of the 

 highest mountains. [Count M .] 



On some Native Iron in the Chalk of Bohemia. 

 By M. Neumann. 

 [Proceed. Imp. Geol. Instit. Vienna, August 1857.] 

 M. Neumann, whose father had first discovered the meteoric iron 

 of Ellbogen (Bohemia), in presenting the Museum of the Imp. Geol. 

 Institute with specimens of the metallic iron found in 1844 in the 

 Planer of Chotzen (Bohemia) on occasion of the driving of a rail- 

 road-tunnel, stated that he himself found sixteen specimens of this 

 iron, of a concentrically laminated structure, partly surrounded with 

 the nodules of the marl in which they were originally found. The 

 weight of the largest specimen was 3iozs. It is stated beyond any 

 doubt that these fragments have all been found in the centre of the 

 hill traversed by the tunnel, at a depth of 120 feet below the surface. 

 They resemble soft iron ; their structure, however, is more distinctly 

 fibrous, without a vestige of crystallization, and not showing Wid- 

 * See also Quart. Journ. Geol. Soc. vol. xi. Part 2. Miscell. p. 16. 



