74 PENNSYLVANIA AND NEW YORK DEVONIAN. [bull. 120. 
sition can hardly be exaggerated. There is no mistake about the 
formation; it is everywhere the same kind of sediment, immediately 
succeeding the bluish sandy shale deposits of Hamilton age; immedi- 
ately preceding the black mud deposits of Genesee age; laid down 
under the same conditions, filled generally with the same kind of 
animal remains, and apparently restricted to an area of grea,t size 
indeed, but in reference to the whole Paleozoic water basin strictly 
local * * * while its two or three special or characteristic shells 
lived only in the northern part of its area. 7 ' 1 
Finally, Prof, Lesley, commenting upon Prof. Claypole's general sec- 
tion of Perry County, iu which 30 feet of very fossiliferous shales at 
the top of the Hamilton were not referred to the Tully limestone, says : 
"If then this zone does not represent the Tully, or Cuboides zone of 
Williams, what does it represent? I can not see that the absence of 
Atrypa cuboides (Rhynchonella venustula) from this perfectly well marked 
horizon on the Delaware, Susquehanna, and Juniata Kivers in Pennsyl- 
vania is of the slightest value, except to a paleontologist who cares 
little or nothing for rock sections. In fact, I can not but regard this as 
a flagrant instance of the superiority of stratigraphy over paleon- 
tology in any broad study of our formations." 2 
In the account of the different sections of this region, it has been 
shown that the lithologic character of the so-called Tully limestone of 
eastern Pennsylvania is not the same as the New York formation; its 
fossils are not Tully species, and it is not capped by the Genesee black 
shale; but on the other hand by argillaceous shales containing abun- 
dant fossils characteristic of the Upper Hamilton. If a correlation of 
this zone with one of central and western New York were attempted, 
I would suggest the encrinal limestone separating the fossiliferous, 
argillaceous Ludlowville and Moscow shales. As the Pennsylvania 
horizon may be represented by any one of the several coral horizons in 
the Hamilton of New York, or by an entirely different zone, such a 
correlation of this zone is very hazardous without careful comparison 
of the species and stratigraphy. 
Finally, if any notice be taken of the evident bias against pale- 
ontology, it might be said that this furnishes an excellent example of 
the superiority of the combination of stratigraphy and paleontology 
over that of stratigraphy and lithology " in anp broad study of our 
formations." 
At first Prof. White regarded the Portage stage as unrepresented 
in eastern Pennsylvania, and said: "It was found impossible to 
identify any of the beds between the base of the Catskill and the top 
of the Hamilton witli the Portage series of other portions of Pennsyl- 
vania, either on lithological or paleontological grounds, and hence I 
have applied the name Chemung to the entire interval, preferring to 
^oc. cit., p. 1315. 3 Ibid., p. 1322. 
