Winchell.] Oo [March 5, 



of Michigan and Canada West, were again identified and ranged witliiii 

 the hniits of the Huron group, next above the Hamilton. 



In Septembers'^ I continued the enumeration of Micliigan species from 

 tlie Marsliall and Huron groups, giving 63 from tlie former, and 17 from 

 the latter. Of the Marshall species, 5 were identified with fossils previously- 

 described from Rockford. Of the Huron species, 6 were identified more 

 or less doubtfully with species from the Hamilton group of New York. 



In November, Col. Jewett^"* and Professor HalF^ both made publication 

 of the results of late observations upon the rocks in Eastern New York, 

 which had been embraced within the limits of the Catskill group upon the 

 geological map of the state. Col. Jewett declared the opinion as the result 

 of his examinations, that the Catskill group did not exist within the limits 

 of the state ; while Professor Hall admitted that the upper limit of the 

 Chemung rocks must be carried in the Catskill mountains, " to an elevation 

 of at least 2,000 feet above tide- water." He stated that it now becomes 

 necessary to restrict the term Catskill group to the beds above [the Che- 

 mung of Delaware county, hitherto regarded as Catskill, ] or to those for- 

 merly known as X and XI of the Pennsylvania Survey." He closes by 

 remarking that ' ' in tracing the Chemung group westward, there are many 

 indications that it may require to be restricted in its designation, ' ' and that 

 ' ' the Waverly sandstone group of the Ohio reports, at one time regarded 

 by [himself] as entirely eqjiivalent to the Portage and Chemung groups, 

 may, in its upper members, constitute a distinct group, though we do not 

 yet know any line of demarkation between them. ' ' 



In 1862, Professor R. Owen^e in his Report on the geology of Indiana, 

 ranges the shales and sandstones underneath the Mountain Limestone in a 

 group designated after D. D.Owen, "sub-carboniferous," regarding them 

 as at the base of the Carboniferous' system, and the equivalent of at least 

 some portion of the Waverly series of Ohio. The Black Slate lie identifies 

 with the Genesee Shale. 



In January, 1863,^'' after having read Col. Jewett' s annoimcement of the 

 unreal character of the Catskill group, and Professor Hall's admission 

 that this group mvist, at least, be very materially reduced in thickness, I 

 gave utterance to convictions which had for some time been maturing, 

 that not only were the Waverly rocks of the West of Carboniferous age, 

 but that also the Chemung of New York, which Hall, White, Whitfield, 

 Swallow, and others had persisted in identifying with these, must also be 

 regarded as Carboniferous. I furnished a synopsis of the paleontological 

 evidences that the Chemung, Waverly, Marshall, Rockford and Burling- 



w Pi-oc- Acad. Nat. Sci- Phil-, September, 1862, p- 405- In the Sixteenth Report of the New Yorl£ 

 Bsgents Professor Hall has given figures of the internal structure of Centronella Julia, described 

 in this paper, from drawings furnished by myself- Pie however," refers the species to Cryptonella— 

 an error which he has since recognized- (Notice of vol- Iv. of the Paleontology of New York, p. 21-) 



"•1 Fifteenth Report Regents New York, p- 198, and Amer- Jour. Sci., [2,] xxxiv, 418- 



65 Canadian Naturalist and Geol-, vol- vii, p. 377- 



66 Indiana Geol- Rep-, 1862, pp- 92, 108, &c- 



6' Amer- Jour- Sci., [2] xxxv, 61- In this paper, an editorial alteration makes mo say " Old Red 

 Sandstone of New York," when I wrote "Old Red Sandstone of Scotland-" 



