436 A. F. Foerste — Fossil localities in the early Faleozoics. 



discrimination, and was one not to be expected of the older 

 survey. 



The work of the older New Jersey survey will therefore 

 practically stand. It is a matter of regret that on the later 

 published geological maps, the Trenton horizon and the so- 

 called Potsdam were not designated by separate colors. But 

 the survey was eminently an economical one, and these horizons 

 representing narrow outcrops of no practical value, and being 

 universally present, where surface deposits did not obscure 

 the geology, and their outcrops being parallel to the upper 

 and lower limits of the limestone series, they offered no induce- 

 ment to separate mapping on a map with the small scale of live 

 miles to the inch ; moreover the expense of printing would 

 have been greatly increased. The more recent discoveries in 

 this region are therefore not so radically new as at first sight 

 might appear to be the case, but they are important from the 

 point of view of paleontologic stratigraphy. They did not 

 change the stratigraphy but they affected the terminology of 

 the lower of the beds here considered. 



While Mr. Nason was studying the White Limestone region 

 of Sussex County, New Jersey, he had the assistance of Dr. 

 C. E. Beecher in the paleontological part of the work. Dr. 

 Beecher found trilobites — Olenellus — in the sandstone at Har- 

 distonville (with Scolithus) (5) and also in the sandstone about 

 a mile south of here at a point near locality 7 on the accom- 

 panying map, and Mr. Nascn himself, found a fragment of a 

 trilobite, presumably Olenellus, near Franklin Furnace, but in 

 his section XIV the exact locality is not indicated. Dr. 

 Beecher also found a species of Obolella in what are very 

 probably the lower parts of the Magnesian limestone series in 

 the old furnace quarry north of the western half of Franklin 

 Furnace Pond ; and fossils were also found by him in " the 

 unchanged blue limestone" (Nason) stratigraphically above the 

 Olenellus sandstone at Hardistonville.* 



As a result of these observations the basal part of the Mag- 

 nesian limestones (and also the white limestone according to 

 Mr. Nason's views of correlation) and the sandstone here 

 formerly called Potsdam were ascribed to the Olenellus 

 horizon. 



Mr. Nason was especially engaged in the study of the white 

 limestones. Consequently he did not follow up the outcrops 

 of the Olenellus sandstone very closely, as is indicated by 

 various omissions within the range of his published map, and 

 by the outlining of various sandstone outcrops. He did not 



*Ann. Rep. of State G-eol. of New Jersey, 1890— The Post- Archaean Age of 

 the White Limestones of Sussex County, N. J., by Prank L. Nason, pp. 31, 43, 

 55. 46, 49, sections X, XIII, XIV. 



