A. F Foerste — Fossil localities in the early Paleozoics. 437 



work his way far enough oat of the inetamorphic white lime- 

 stone region to see that his discoveries necessitated the relega- 

 tion of all the so-called Potsdam sandstones and basal Mag- 

 nesian limestones and these alone to the Olenellus horizon. 

 This is shown bj his final conclusions that a careful search for 

 fossils must be made "in the whole belt, or rather belts of 

 limestones, sandstones, slates, and shales hitherto called and 

 regarded as Potsdam, Trenton, and Hudson River " (italics 

 not in the original. See pages 49, 50 of the Peport.) 



When the writer was called into New Jersey by the needs 

 of the survey of the Archaean Highlands under the more 

 immediate charge of Prof. J. E. Wolff and his assistant, Mr. 

 P. S. Tarr, his first duty was to trace the Cambrian sufficiently 

 out of the metamorphic area to determine what was Pre-Cam- 

 brian and the second was to investigate the doubts recently 

 thrown upon the previous determinations of Trenton and 

 Hudson Piver strata. 



The last was quickly solved by an irregular section from 

 the Archaean at Andover to the Oneida conglomerate of the 

 Kittatinny Mountain range at Culver's Gap. The thin blue 

 limestone overlying the Magnesian limestones and underlying 

 the Hudson Piver was found to everywhere contain fossils, 

 such as are found in Trenton rocks. In the thin blue lime- 

 stones of this section fossils were for instance found on the 

 eastern side of the road running north about half a mile west 

 of Long Pond, and some distance north of an old slate quarry, 

 on the eastern side of a synclinal (54). Also on the western 

 side of this synclinal, directly west of a strong bend in the 

 road almost half a mile north of Stickle Pond (55). Again 

 on the eastern side of the next synclinal, three-eighths of a 

 mile directly south of the great slate quarries a short distance 

 southwest of Newton (56). This exposure is in a field, on the 

 eastern slope of the hills. Also on the western side of this second 

 synclinal, along the New York, Susquehanna & Western rail- 

 road track a short distance south of Augusta, at a curve in the 

 railroad. Finally, half a mile east-northeast of Branchville, 

 where this limestone finally disappears under the Hudson 

 Piver, so as not to appear again in western New Jersey. 



.Parts of the first task were equally easy owing to the sim- 

 plicity of the strike and dip of the Olenellus sandstone which 

 varies too little from outcrop to outcrop to make it difficult to 

 trace the formation. Moreover in most of the outcrops in the 

 fairly continuous line of exposures between Hardistonville 

 (5) and the locality tw r o miles southwest of Franklin Furnace 

 (15), fossils are very abundant in certain layers of the sand- 

 stone, so that they are very readily found. Their locations are 

 sufficiently indicated in the accompanying map. Fossils are 



