Manlius Formation of New York. — Schuchert. i6i 
limestone" in the New York series. To do this, it will be nec- 
essary to give a number of sections on the east and west sides 
of the Helderberg mountains. 
THE ORIGINAL CORALLINE LIMESTONE. 
The Coralline limestone is described by Hall as follows :* 
'Tn the neighborhood of Schoharie, and extending along 
the base of the Helderberg mountains and along the Hudson 
river, there is a thin mass of limestone, characterized by an 
immense number of corals, chiefly favosites, and which forms a 
band so distinct from any other limestone that it has been for 
many years known by this name. Besides the corals, it con- 
tains other fossils peculiar to it, and which in some localities 
are sufficiently characteristic in the absence of corals. 
"In its western extension, this limestone can be traced as 
far as Herkimer county ; but being only a few feet thick, its 
continuity further westward has not been ascertained in a sat- 
isfactory manner." 
The position of the Coralline limestone is clearly indicated 
in the Schoharie section as worked out by Stevenson and stated 
beyond. This section in itself, however, does not locate the 
true position of the Coralline limestone in the generalized New 
York series. 
The first attempt at correlating the "Coralline limestone" 
appears to have been by Hall in 1843. f He states "The Cafeii- 
ipora ['=Halysites] is in a mass, which at Schoharie is known 
as the 'Coralline limestone,' and which is separated from the 
water-lime [of the Manlius] by twenty-five feet or more o^ a 
soft ash-colored rock destitute of fossils. This coralUne lime- 
stone contains no fossils in common with the true waterlime 
above [=Rondout beds. This is an error as will be shown 
later]. It rests upon a green shale with iron pyrites, which, 
from the absence of the Medina sandstone and conglomerate, 
is succeeded below by the Hudson River group. 
"The point to be decided is, whether the green shale, con- 
taining iron pyrites, is the representative of the Clinton, or of 
the Onondaga salt group. If the former, then the 'Coralline 
limestone' holds the place of the Niagara limestone, and must 
be considered its equivalent; but if the latter, then it is a part 
• Nat. Hist. iV. Y. Pal., ii, 1852, p. 321. 
t Trans. Assoc. Amer. Geol. Nat., 1843, p. 292. 
