Claypole.] 5o0 [Oct. 20. 1882. 



ous shales, argillaceous limestones and iron ores. For the most part the 

 lowest of these is an impure, earthy, haimatite or a very ferruginous shale. 

 Apparently these two materials belong to the same bed, but apjiear dif- 

 lerentlj^ at different places. Near Bloomfield it is a haematitic shale of no 

 value, and yielding thus far no fossils except on its upper margin, where 

 an undescribed Betjrichia occurs in great numbers. A few miles south ot 

 Bloomfield, in Sandy Hollow, it is a tolerably pure red ochre, much ot 

 which has been dug and ground for paint, but apparently the work has 

 not yielded sufficient profit to lead to its continuance. Here also I have 

 found no fossils, but have reason to Uiink that some might be obtained it 

 the exposure were larger. This ochre lies close against the Oriskany 

 sandstone, here nearly vertical. At a short distance further south the same 

 bed again yields red ochre, which has been dug out close to the Oriskany 

 sandstone. The best layers for this purpo^.e are the lowest, and these 

 have thus far yielded me no fossils. But about ten feet higher up, where 

 the beds are less ferruginous, I have met with abundance of specimens ot 

 Atrypa impressa Hall. They are well marked and in a good state of pres- 

 ervation, being little altered by compression. They also occur solely as 

 internal casts. 



Regarding this species Prof. Hall says (Pal. of N. Y., Vol. 4, p. 316) : 

 "This form of Atrypa occurs in the Schoharie grit. It is not known to 

 me in any other geological formation." Also (p. 315), "The casts of the 

 interior are more abundant than any other condition of the fossil in the 

 Schoharie grit." 



From the above facts the inference seems warranted that these two grits 

 of Eastern New York or some parts of them are represented by the ferru- 

 ginous shales above mentioned. The sandstones indicate a shore line for 

 the time being extending, during the whole or part of the period, from 

 Eastern New York through Northwestern New Jersey into Eastern Penn- 

 sylvania, But west of this there is no evidence of anything but open sea 

 for a long distance, and the finer sediments accord with the conclusion. 

 The same species, Atrypa impressa, which lived near the shore or was 

 washed ashore when dead and was buried in the sandstone in New York, 

 sank in Middle Pennsylvania into soft oozy shale and was there preserved. 



What the conditions were which produced the deposition of marine iron 

 ores and ochres it is impossible at present to say. We are too ignorant of 

 the processes of marine metallic sedimentation to do more than guess at 

 them — a useless expenditure of time and thought. 



