6 



TRANSACTIONS OF THE 



other undetermined species occurs in Ireland. In 

 England I am not aware that any have been described 

 in the same series of rocks. On the authority of M. 

 Ad. Brongniart, Dr Harlan refers to two species in the 

 transition limestones of Canada. Within the space of 

 a few months, I have observed Fucoides JUleghaniensis, 

 with other species, in the brown sandstone of Tussey 

 Mountain, near Alexandria in Huntingdon county. Fur- 

 ther south I noticed them in a similar rock in Bedford 

 county. In the white sandstone of the seven Mountains, 

 in Centre county? F. Alleghaniensis, and several others 

 prevail at the height of seventeen or eighteen hundred 

 feet above the sea. At Muncy Ridge, near Muncy, 

 in Lycoming county, I obtained splendid specimens of 

 F. t/lllcghaniensis, on white sandstone ; and in the same 

 vicinity other species in grauwacke slate. At the latter 

 place and near Lewistown they occur at 450 feet above 

 tide water. In the lower part of the old red sandstone, 

 on the eastern slope of the Alleghany Ridge, I have ob- 

 served fossil fuci of simple form, associated with Pro- 

 ducts, at points more than a hundred miles apart. 



Detached fragments containing specimens of F. Mle- 

 ghaniensis — amongst others, that from whence Dr Har- 

 lan's figure and description are derived — have not unfre- 

 quently been observed among the talus of the ridge, 

 called Shade Mountain, on the north side of the Juniata 

 river ; and in the deep valley of " the Long Narrows," 

 below Lewistown. 



Towards the close of the last year the strata in which 

 these fossil plants occur in situ, came under my observa- 

 tion, and I proceed to describe the circumstances attend- 

 ing their position. 



DSI 



