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



be classed as Olenellus Cambrian until fossils are found which 

 will shed further light on the subject. That the lower paleo- 

 zoic section of northern New Jersey is still preserved in all its 

 features in eastern Pennsylvania is readily seen along the mag- 

 nificent sections offered by the Lehigh between the Kittatinny 

 range and Bethlehem. Underlying the Oneida conglomerate 

 of Kittatinny Mountain, are the shales and slates of the 

 Hudson River series. The top of the underlying great lime- 

 stone series is again an especially constant fossiliferous horizon 

 of Trenton age. As in the Vermont localities to be described 

 later, these Trenton fossils occur not only at the top of the 

 limestone series, but also in thin beds of limestone intercalated 

 in the base of the shales referred to as Hudson River. Such 

 intercalated limestones containing Trinucleus and other fossils 

 may be seen toward the base of the shales on the road leading 

 diagonally from North White Hall P. O. on the railroad, 

 southward up hill above the cement works along the track, 2J- 

 miles north of Hockendauqua. Below the limestone series 

 the basal Cambrian sandstone occurs again, of moderate thick- 

 ness, having here however the character of a quartzite, there 

 being no disintegration, as in most of the New Jersey expo- 

 sures. The base of the sandstone is distinctly conglomeratic, 

 and rests unconformably upon Archsean gneisses, but with a 

 less marked angle of discordance than in the northern New 

 Jersey exposures. Some of the lower beds of sandstone are 

 tinged with purple, and in these it is not uncommon to find 

 large coarse tubes, burrowed vertically into the sand, varying 

 from 10 to 20 mra in thickness and from 70 to 150 mm in length, 

 usually filled up with a lighter colored sand than the rock in 

 which they are found, being evidently the same kind of sand 

 as that forming the next higher layer, in each case. The wash 

 of the sea seems to have partly broken down the top margin 

 of the tubes before the filling with sand was completed, the 

 result is a tube of the appearance of Monocraterion Lesleyi 

 Prime, found in the basal members of the limestone series, a 

 quarter of a mile northwest of Helfrich's Spring and again in 

 limestone three quarters of a mile northwest of Durham iron 

 works. Although this is a tempting opportunity to conclude 

 that these tube casts indicate the Cambrian character of the 

 basal portions of the limestone series, a fact already known for 

 New Jersey and Vermont, it must be admitted that worm 

 burrows are hardly to be given the value of determinative 

 fossils. 



While the New Jersey Survey has always acknowledged the 

 Green Pond Mountain series as a terra incognita or at least a 

 region of many unsettled questions, as is evidenced among 

 other things by the coloring it was obliged to employ in its 



