124 Wisconsm Academy of Sciences, Arts, and Letters. 



which were described by Mr, Alexander Winchell* in 1864. 

 I was assured that there is a quarry of the rock in place 

 near by, but a subsequent visit has shown that the sandstone 

 only exists at this point as loose pieces. In a short time a 

 larger number of Potsdam fossils were obtained. They were 

 /Scolithus Linearis, Hall, Orthis Barahooensis, Wicchell, Strapa- 

 rollits primordialis, Winchell, Dicellocephalus Minnesotensis, 



A, Abelman; B, Baraboo; B R, Baraboo River; L N, Lower Narrows; U N, Upper 

 Narrows. 1, DeviPs Lake; 2, 3, Potsdam Sandstone; 4, Section; 5, Limestone. Scale, 

 three-twentieths of an inch equal to a mile. 



Owen. At the locality marked (4), however, is a section (fig. 

 2), which is truly magnificent in its exposure of all the rocks, 

 which belong to this region, in their stratigraphical relations, 

 except the limestone. It is at the railroad station, Abelman, 

 The Baraboo river, in forming the upper narrows, has left up- 

 on the east side a nearly vertical section, about half a mile 

 long and 800 feet high at the highest point. This section is 

 of a core of tilted rock, flanked on both sides by horizontal 

 Potsdam sandstone and conglomerates. No doubt can there- 

 fore remain that the tilted rock is Pre-silurian. 



The dip of the entire section of Azoic rock is to the north or 

 slightly west of north. Its face is cut by numerous vertical 



+Am. Jour. Sci. and Art, II, yoI. XXXVII, p. 226. 



