IX APPENDIX; 



rostral cavity, left by a prominent, narrow, internal ridge or sep- 

 tum, similar to that seen in Spiriferina. In the same beds with 

 these, I also found several casts agreeing well with the Chemung 

 species Leior^hynchus mesacostalis, and Orthis impressa, together 

 with the Chemung and Hamilton forms Atrypa reticularis and 

 Martinia umhonata: likewise a small hemispherical Productus, 

 a small plicated Bhynchonella, and an Avicula or Fterinea, like 

 A. spinigera. 



From such an assemblage of fossils, it can scarcely be doubted 

 that these beds belong to the horizon of the Chemung group of 

 the New York Devonian series. It is true, Spirifer mucronatus, 

 is, I believe, not there known above the horizon of the Hamilton 

 group, but Prof. Henry D. Rogers states that it occurs in the 

 Chemung in Pennsylvania, while the associated species form 

 together a group of fossils nowhere, so far as I am informed, 

 ever found below the horizon of the Chemung. 



About half a mile east of the locality where the above-men- 

 tioned fossils were found, I collected from loose pieces of fine- 

 grained, gray, somewhat gritty rock, along the bed of a little 

 mountain stream, a Schizodus apparently identical with a New 

 York Chemung species ; and from a cut a few hundred yards 

 further eastward, from a similar rock in place, several bivalves 

 like Chemung forms, along with casts of the well-known Chemung 

 species Bjnrifer disjunctus. 



The beds all along here continue to dip at the same high angle 

 to the southeastward, and become rather more gritty in that 

 direction ; while immediately east of the last-mentioned locality, 

 small masses of whitish, more or less pebbly sandstone had slidden 

 from the slope above the road. This material seems, however, 

 scarcely to form a continuous bed here, but apparently passes 

 into fine-grained, hard gray rock, nearly or entirely without peb- 

 bles. This, more or less pebbly and at places whitish grit, is 

 very probably the same seen dipping to the northwestward, five 

 miles below the springs on Howard's Creek, though here it seems 

 to be much less developed as a distinct mass from the other beds. 



At a point some three-fourths of a mile east of the Alleghany 

 tunnel, exposures were seen along the road, of rather massive 

 beds of hard, bluish-gray, more or less gritty rock, alternating 

 with softer crumbling material of brownish color, the whole being 

 much like the beds seen in the cut five miles below the springs. 

 At one place, thin local seams of dark shale, and some little coal 

 were seen intercalated among these rocks. A little east of this 

 the road curves around to the left, in a northeast direction, and 

 enters a long open cut, leading to the southwestern end of Lewis's 

 tunnel ; and it was at the bottom of this excavation that the 

 plants under consideration were found. 



The base of this excavation is here perhaps some twenty odd 

 feet lower than the exposures containing the thin seams of dark 



(34) 



