-/ '6 J. A. UDDEN 



miles goes to show that the conditions under which they were 

 laid down were uniform over wide areas, and such conditions are 

 not to be found in the proximity of the shore line. Everything 

 considered, this unconformity was most likely caused by changed 

 conditions in the sea and its currents, in all probability conse- 

 quent upon some orogenic movements affecting the ocean basin. 

 Fossils. — The fossils so far found in this formation are few, 

 but they are many enough to indicate that it must be referred 

 to the Upper Devonian, or the Chemung. The fibrous plant-like 

 impression from number 3 was found extending over a slab a 

 foot long and about three inches wide. In the pyritous layer in 

 number 2 there was a similar, much smaller, impression. The 

 mold in both instances was covered by a bituminous crust an 

 eighth of an inch in thickness. In this no organic structure 

 could be detected. The lingulas which occurs in numbers 3 and 

 6 have been submitted to Dr. Charles Schuchert, who says that 

 one species is apparently identical with an undescribed spe- 

 cies, from nodules in the "Black Shale," or the Genesee; 

 one is related to L. melie Hall, from the Cuyahoga shale ; and 

 another to L. nuda Hall, from the Hamilton. The author has 

 also observed one lingula in number 6, which resembled L. sub- 

 spatulata M. and W. Some small bilobate fossils from the same 

 number in the general section have been examined by Dr. J. M. 

 Clarke, who has reported that they are identical with Spathiocaris 

 emersoni Clarke. This fossil occurs in the Portage group in 

 New York, and has not previously been reported from the West. 

 In the same layer the author found one fossil which resembled 

 Solenocaris strigata Meek. This form is known to occur in the 

 " Black Shale " of the Ohio valley. The cast of a gasteropod, 

 found in the stony ledge number 3, was too fragmentary for 

 more exact determination. Dr. C. R. Eastman has examined all 

 the fish remains found, and states that the greater number of the 

 teeth from numbers 1 and 2 are Ptychtodus c alee 'olus M. and W. 

 He finds them on the average smaller than usual, but in other 

 respects perfectly like the type. He also reports that there are 

 several other forms of flat, crushing teeth, which are allied to 



