Report of the Curator. 9 



alone, the Waverly series from tlie Cliemung, notwithstanding 

 there are some species common to the two formations.* This 

 question, however, had never been set at rest until the explora- 

 tions of Dr. ISTewberry, and his corps of assistants, in tlie 

 geological survey of Ohio during the past year. 



Dr. Newberry has found the beds of shale, or shaly sandstone, 

 containing Splrifera dlsjioncta., Leiorhi/nehus quadricostata, 

 and other characteristic fossils of the Chemung group, passing 

 entirely beneath those beds holding the characteristic fossils of 

 the Waverly sandstone series, thus establishing the fact of 

 superposition. This is a ver}'- gratifying result, inasmuch as 

 the shaly rocks below had heretofore been regarded as non- 

 fossiliferous, and there was, therefore, an entire absence of evi- 

 dence of this kind from the lower rocks. During the investiga- 

 tions for the fourth volume of the Palaeontology of JN'ew York, 

 and the collection of specimens for the same, I instructed Mr. 

 C. A. White, then an assistant in the work, to make careful 

 sections of the strata at various points from Cuyahoga Falls, 

 in Oliio, to the western line of N"ew York. These sections, 

 together with the collections made, did not reveal any facts of 

 new interest, or furnish information for any satisfactor}^ conclu- 

 sion regarding the superposition of the formations. 



Notwithstanding our jDvesent clear recognition of the order of 

 succession among these formations, we have been greatly inter- 

 ested in observing, among the collections made from the upper 

 part of the Hamilton group in eastern New York, some species 

 which bear a much nearer resemblance to those of the Waverly 

 group than they do to any known species in the Chemung, and 

 which, upon cursory examination, may be regarded as identical 

 with species from the Ohio formation. 



In other parts of the State there are difficulties of equal magni- 

 tude in regard to harmonizing the old geological map witli known 

 facts regarding the geological structure. The statement is true 

 of the country lying east of the Hudson river, and more espe- 

 cially of the area occupied by the older rocks in the northern 

 part of the State, colored as primary. We have long had rea- 

 son to believe that the geological formations of this region 



. * In volume iv, I have dest-ribed species of Ivinonla and Discina from the 

 Waverly sandstones and associated shales ; but a comparison of the species of 

 other genera satisfied me of the great difference in the faunae of the two forma- 

 tions, and I therefore omitted from the volume others previously described by me 

 from the rocks of Ohio. 



[Assera. No. 133.] 2 



