202 PROCEEDINGS OF THE AMERICAN ACADEMY 



found Machirea matutiim and M. sordida in great al)uiKlance ; also 

 the species figured by Hall under the name of Turbo diUtcula. Euom- 

 phalus rmkuKjulatus occurs here but rarely. I shall describe them 

 all shortly. Not a vestige of any Medina sandstone or Middle Silu- 

 rian species is to be seen. I followed the Calciferous back three miles, 

 and then came on the Red Sandrock. The two formations are in 

 contact, but I could not ascertain which is the uppermost, on account 

 of the disturbed state of the strata. I then traced the Red Sandrock 

 down into Vermont. Hearing that Dr. Hall of Swanton had found 

 Trilobites in it, I called upon him, and he accompanied me to the place. 

 It is just two miles south of the Province line, and about one mile or 

 a little more east of Highgate Springs. It is in a hill about a hundred 

 and fifty yards east of the house of a man by ilie name of Church. 

 We found a number of specimens and a small Theca. They are ex- 

 actly such forms as I expected to find. I believe these are the only 

 fossils found in the Red Sandrock, and as they prove tliis rock to be the 

 base of the Lower Silurian, what are we to call the immense forma- 

 tion of slate that lies beneath it? Surely not Hudson River grouj). 



" In about three weeks I intend to go out to the Eastern townships 

 again, and will let you know the results. You say that Prof. J. Hall 

 'still declares that the position of Sir William Logan does not affect 

 the stratigraphy in the least.' Sir William's position brings down the 

 Quebec rocks from the top of the Lower Silurian to the bottom. It 

 makes all those rocks in Vermont (called Medina sandstone) either 

 Potsdam or Calciferous, and consequently the slates which can be seen 

 lying below them at Snake Mountain, at Sharp Shins, and at Phillips- 

 burgh are older than the Lower Silurian. 



" It is upon the age of these Vermont rocks that the whole Taconic 

 question depends. If they are Medina sandstone, and if the slate 

 beneath them is Hudson River, then there is no Taconic system. But 

 if the Red Sandrock of Vermont is Calciferous or Potsdam, then 

 Emmons is right. Sir William concedes to the fullest extent that 

 they are of the age of the Cahtiferous or Potsdam, and therefore he 

 admits all that Emmons requires. If that does not affect the strati- 

 grai)hy, I do not know how it can be affected. As I have often stated 

 in my former letters, it will be some time before all will be cleared up. 



" It is unfortunate that in New York there are no active and un- 

 prejudiced geologists to enter into this vast field of research. All that 

 has been done during the last two years (I mean in the way of publi- 

 cation) has been effected in a roundabnut way through foreign geolo- 

 gists. It should have been done in New York. I hope Jules Marcou 



