SUESS KOSSEN BRACHIOPODA. 27 



covered in Switzerland as far as the neighbourhood of the lake of 

 Geneva, the closer investigation of which is of the greatest interest, 

 we are quite warranted in tracing the Koessen strata from the 

 Brandner Ferner on the frontier of Vorarlberg to the immediate 

 vicinity of Vienna. They extend undoubtedly from 27° to 34*^ long, 

 along the northern declivity of the Alps, the line joining the most 

 distant known localities being above 100 geographical miles in length. 



The localities where the Brachiopods have been found are distri- 

 buted in the following manner. The most eastern are close to the 

 great break in the Alpine accessory zone between Vienna and Glogg- 

 nitz (Gumpolts Kirchen, Helenathal and Siegenfeld near Baden, 

 Hirtenberg, and Enzesfeld) ; there are otliers more to the west near 

 Harnstein, and the richest are in the upper valley of the Piesting, as 

 far as the Klosterthal (Walleg, Oed, Mandlinger Wand, Kitzberg near 

 Pernitz, Frohberg near Weidmansfeld). To the northward there 

 are some in the environs of Kleinzell (near the Unterer Ilebenbauer), 

 and to the southward at the Fadner-Kogel near Buchberg ; westward, 

 at the Tiirnitzer Ilogerkogel, and also in the envircnis of Maria-zell 

 (Grash in the Hallthal, Burger-Alpe). As Von Ilauer observes, the 

 above-named localities are limited northward by the curved tract of 

 variegated sandstone which marks the rupture of the extreme northern 

 wave of elevation (Aufstauungs- Welle). M. Czjzek found them only 

 at one place in tlie region of the variegated sandstone, viz., at liat- 

 terbash near Frankenfels. The Koessen strata on the northern de- 

 clivity of the Alps are divided into an eastern and a western region by 

 the advance of the variegated sandstone, from which they are almost 

 entirely excluded nearly as far as the central Alpine mass. After all, I 

 do not think such limitation of any particular importance, as it could 

 possibly have originated subsequently to the deposit of these rocks and 

 on account of the position of the central axis ; and the more so, since 

 no striking palseuiit* tlogical or petrographical difference has been 

 pointed out between the eastern and the western portion. 



As all the above-quoted localities are at a considerable distance 

 from the central mass, we may conclude that the Koessen strata are 

 wanting in the mountain masses which in the Valley of the Enns 

 form the great fracture accompanying the crystalline rocks. They 

 are not met with near the mass of the Dachstein, nor probably in 

 any of the mountains of the vicinity (Sarstein, Grimming, &c.). 

 Generally the localities are very much scattered in this portion of the 

 Alps ; and are just sufficient to point out the connexion of the richest 

 extreme eastern and western localities along the northern declivity. 



Brachiopods characteristic of the Koessen strata are found at the 

 Schaf berg (between the Vonmauer and the Miinchen-See), near Aussee 

 (Scheibenweisenweg to the Moosberg), near Salz])urg (Scliubergraben 

 near Adneth, Merlbach near Gaisau), and at the Baukengraben 

 (Steier). 



The environs of Unken and Loper, so diligently investigated by 

 MM. Emmrich and Peters, exhibit Koessen strata at several places; 

 and further west lies Koessen, the typical locality. The exact place 

 is in the Klamm between Koessen and Reit, on the Austrio-Ba- 



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