130 THE DEVONIAN AND CARBONIFEROUS. [bull. 80. 



sandstones are darker in color and thin, tough, and wave-marked or flaggy. Pale- 

 on tologically, however, the transition is more marked. 



The upper part of the Portage appears to be utterly barren except in an occasional 

 thin stratum of green shale, a Cardiola sjneciosa, or a small Palwoneilo, or Leda may 

 appear. 



As soon, however, as we reach the true Chemung rocks we meet large Productella 

 lachrymosa, Amboccelias and Spirifers of the Chemung types. * * * 



To the author of this bulletin the facts reported by Mr. White in the 

 Keport of Progress G 7 were not startling, but what he was ready to ex- 

 pect from his studies in New York. He expressed his agreement thus : 



In regard to the identification of these Upper Devonian faunas of Columbia County, 

 Pennsylvania, in the association of species and the relative order of the sub-faunas, the 

 record agrees in general with that of the series exposed along the same meridian 

 farther north in New York State. l 



The following year, 1884, the same author read a paper before the 

 American Association on "Geographical and physical conditions as 

 modifying fossil faunas." 2 In this paper application of the principles 

 above described is made in the study of sections of the Devonian rocks 

 east and west of those described in the Bulletin No. 3. By dissecting 

 the faunas of each section and comparing them consecutively across the 

 State, is it shown that there are changes in the composition of the faunas 

 coordinate with changes in the deposits. Among other examples the 

 occurrence of Castkill type of fossils with Catskill character of rocks 

 in Chenango and Otsego Counties, New York, is reported entirely below 

 genuine Chemung fossils, in the Oneonta formation. 



In the discussion which followed, Mr. Hall, to whom the objectionable 

 identifications of the Pennsylvania Report G 7 had previously been re- 

 ferred, again objected to the report that Spirifera mesostrialis and S. 

 disjuncta were found together, on the ground that they represent dif- 

 ferent zones and should not occur together ; also, he objected to the 

 interpretation of strata as " Chemung-Catskill," claiming that these 

 are two distinct formations with distinct faunas, and it was not reason- 

 able to expect the two to be blended. At the same meeting, in a paper 

 read by Mr. Hall, this opinion is further illustrated by his interpreta- 

 tion of a section in Warren County, Pennsylvania. 3 In the section de- 

 scribed about 1,500 feet of Chemung rocks are reported with Chemung 

 fossils, followed immediately, and without sign of unconformity, by 

 Waverly sandstone rocks with Waverly fossils. Between the two is 

 marked " the place of the Catslcill," where, it is stated, u there is a hiatus 

 which in eastern New York and Pennsylvania is marked by the pres- 

 ence of measures having a thickness of from 3,000 to 5,000 feet." 



The interpretation of the facts is " that there has been a long interval 

 of time between the final deposition of the barren Chemung shales and 

 the fossiliferous Waverly sandstones, or that the deposition of the 



1 See " The Spirifers of the Upper Devonian," by H. S. Williams, Science, vol. 3, p. 374. 



2 Proc. Am. Assoc. Adv. Sci., vol. 33, p. 422, et. seq. 



3 On the intimate relations of the Chemung group and the Waverly sandstone in northwestern 

 Pennsylvania and southwestern New York, by James Hall, Proc. Am. Assoc. Adv. Sci vol.33, p. 416. 



