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FAUNA OF THE AGONIATITE LIMESTONE OF 
ONONDAGA COUNTY, N. Y. 
Joun D. WILson. 
OcToBER 18, IQOT. 
The transition from the Corniferous limestone, gc of the 
geological series, to the Marcellus shale, 10a, is abrupt. Going © 
eastward along the Jamesville and Manlius road in front of the 
new penitentiary, one may travel for a quarter of a mile on a 
smooth, natural pavement, the top of the Corniferous. At the — 
burying ground, east of Jamesville, there is a sudden rise in the 
road. Upon inspection the hill is found to be composed of a 
black, fragile shale so highly charged with bituminous matter 
that will often blaze for a. time if thrown upon a fire. In this 
shale which is almost destitute of fossils, at a distance above the 
Corniferous, varying from a few inches to fifteen or twenty feet, 
occurs what is now known as Agoniatite limestone. The forma- 
tion is composed of two layers joined by a horizontal, suture-like, 
seam which is extremely difficult to open unless the rock has been 
exposed for some time to the weather. 
It extends from Schoharie county on the east to Ontario 
county on the west. In Onondaga county, where the formation 
is best known, and where it probably has its fullest development, 
the lower layer is twenty-eight inches in thickness, and the upper 
one six inches. ‘The lower layer has no cleavage lines. It is com- 
posed of irregular nodules of very hard substance, interspaced 
by softer material. It contains but few fossils and these are not 
well preserved. The upper layer has cleavage lines which form 
an angle of about thirty degrees with the connecting suture. This 
makes it difficult to separate fossils from the matrix, for they lie 
in a horizontal plane. 
Both layers bear abundance of iron, have a distinct petro- 
leum odor when first broken, and soon disintegrate when exposed 
to the atmosphere. 
The upper six inch layer abounds in fossil remains, the most 
abundant beingA goniatites expansus and Orthoceras Marcellense. 
