Rocks and Fossils of Philli'pshurgh, C. E, 323 



be referred it seems highly probable that they belong to each 

 other. 



Locality and Formation. — Phillipsburgh, Calciferous Sand- 

 rock. 



4. Grey and Red Sandstones. 



On the eastern side of the limestones at Phillipsburgh there is 

 a ridge of grey sandstone which usually weathers to a light reddish 

 or yellowish colour. This ridge terminates about two miles north 

 of the road to Freligsburgh. It then appears to be overlaid first 

 by the magnesian limestone and above this the blue limestone. 

 The immediate line of junction of the magnesian rock with the 

 sandstone was not observed. This ridge runs in a southerly 

 direction into Vermont. No fossils were found in it in its pro- 

 longation into Canada, but hearing that the Rev. J. B. Perry and 

 Dr. Gr. M. Hall, of Swan ton had discovered trilobites in it, I 

 called upon them and they kindly accompanied me to the locality. 

 The place is about two miles south of the Province line and one 

 mile east of the Highgate Springs. The rock is here a deep red 

 sandstone, the typical red sandrock formation of Vermont. We 

 collected numerous specimens of the head of a small species of 

 Conocephalites. No other fossils except a small Theca were ob- 

 served. It thus seems clear that this rock is not the Medina 

 sandstone but a formation somewhere near the Potsdam 

 sandstone. 



On looking over the back numbers of Sillimans Journal I 

 find that the resemblance of this trilobite to Conocephalites was 

 recognised by Prof. C. B. Adams in 1848, but he did not attach? 

 to it any importance as indicating the age of the formation. In 

 fact the geological position of Conocejyhalites was not then gene- 

 rally known ; Barrande's " NbHce preliminaire^^ in which the cha- 

 racters of the Promordial Zone were first clearly pointed out had 

 been then only lately published (in 1846). As everything rela- 

 ting to the question of the age of these rocks is of interest I shall 

 quote Prof. Adams paper in full. It seems necessary first to ex- 

 plain that Dr. Emmons contends that the red sandrock on the 

 top of Snake Mountain is the Calciferous sandrock and that the 

 slate beneath it is his Taconic slate. He says that a great fault 

 runs through the mountain which throws the rocks down on the 

 West side so that the top of the Utica slate lies below, or at 

 a lower geographical level than the Calciferous. 



