Wincliell.] ' ^ [March 5, 



regarded as contemporaneous. In a note lie remarks that tlie Catskill 

 rocks of Eastern New York must probably be restricted to "the coarse 

 conglomerate of the upper part of the Catskills," which corresponds to 

 the outliers occiirring on the summits of the higher hills in Western New 

 York, and to a continu.ous formation beyond the limits of the State in 

 Pennsylvania. 



In July, 1865, I presented^^ a continuation of the results of my re- 

 searches in the paleontology of the rocks under consideration, embracing 

 descriptions and notices of fossils from the States of Michigan, Ohio, In- 

 diana, Illinois, Iowa and Missouri, in all which I had made personal ex- 

 plorations. The number of species noticed in this paper is 94, of which 

 36 were therein first described. This paper presents a shadowing forth 

 of conclusions which I feel constrained to think, demand the candid con- 

 sideration of paleontologists. To this time I had been impressed with 

 the expectation that the Chemung rocks of New York would eventually 

 be synchronized with the Waverly series of Ohio upon paleontological 

 grounds. It had generally been supposed that the Chemung strata em- 

 braced from three to six species which could be identified with western 

 species from the horizon of the Waverly sandstone ; and that on the com- 

 pletion of the study of these rocks by the paleontologist of New York, 

 further identifications would be effected. At the suggestion of Professor 

 Hall, I spent several days with him in February and March 1865, in 

 making direct comparisons between the types of the Chemung group of 

 New York and a collection of fossils supposed to belong to the same 

 horizon, from the Western States. The western fossils brought under 

 comparison numbered about 175 species. To the great surprise of both 

 of us, we were unable to identify a single species with Chemung types. 

 All the reputed identifications had to be abandoned. This is a conclusion 

 in which Professor Hall united with myself. 



Not satisfied to be completely frustrated in my attempt to determine 

 the New York equivalent of our western sandstones, I turned my atten- 

 tion to an examination of the facts in connexion with strata occupying a 

 IDOsition in Western New York above the typical Chemung strata. Pro- 

 fessor Hall'^s had described a conglomerate in Western New York as ter- 

 minating the Chemung series, and had remarked that it contained Che- 

 mung fossils ; though it does not appear that any critical and final exam- 

 ination had been made upon this point. The Catskill group had been 

 restricted at the east to cei'tain conglomerates caj)ping the Catskill moun- 

 tains, and at the west to detached outliers of sandstone becoming also at 

 times conglomeritic.''6 In addition to these he had described a conglom- 

 erate which he identified with the Carboniferous of Pennsylvania and 

 Oliio''^. It does not appear that any two of these conglomerates had been 



74 Proc. Acarl. Nat. Sci. Phil.. July, 1865, p. 109. The materials for this investigation, besides my 

 own collections in different States, embraced Col. Whittlesey's Ohio collection and numerous resi- 

 dual investic/aiida of the White collection of the University, from Iowa, Missouri and Illinois. 



75 (Jeol. Eep. 10th Dist. N. Y., p. 202 and elsewhere. 



78 Canadian Naturalist, vii. p. 380. 77 ^gp. Geol. 10 Dist- N. Y., p, 2S4. 



