88 TRANSACTIONS OF THE [pEC. 16, 
From a lithological standpoint we note :—First, the prevaling 
shaly, nodular and impure character of the lower portion of the 
formation. 
Second: The tendency of the fossiliferous portions to occur 
in lenticles, usually of a light gray color, owing to the prepon- 
derence of lime, and often composed entirely of an agglomera- 
tion of fragments of one or two species. The transition between 
the light colored fossiliferous and the dark compact limestones 
often occurs with abrupt contact or line of demarcation; the 
lenticles evidently being depressions filled up with fragments, 
in an otherwise even surface of the finest carbonaceous lime 
sediments. 
Third: Judging from the thinness of most of the layers and 
their frequent shaly partings, oscillations of the sea bottom and 
successive depositions of fine silts must have followed each 
other in periods of very brief duration. During a few longer 
periods quiet seas prevailed which deposited considerable thick- 
nesses of pure limestone of blue-black color, in which the tvilo- 
bites were entombed entire. 
Fourth: Zones, usually of less than one and a-half feet thick 
of lighter gray color occur chiefly near the central mass, in 
which the fossils are altogether comminuted. This is also the 
case with the uppermost gray portion, while many of the fossils 
of the intervening portion, especially in the Rajinesquina del- 
toidea zone are preserved nearly intact. Finally sedimentation 
closed with long continued shore deposition, in which the frag- 
ments were finely broken or ground to powder, which afterward 
dissolved and crystallized, and which, possibly owing to the ab- 
sence of plant life, retained its light color. A few short periods 
of finer sedimentation intervened between the longer periods of 
fragmental deposition and preserved the existing “fauna. 
The subsequent shaly deposits which gradually ‘led to the slate 
formations of the Utica do not appear at Trenton Falls. 
SUMMARY. 
The results obtained may be summarized as follows : 
Urica shale is not found nearer than Nine Mile Creek, East 
Trenton, and no upper stratigraphic boundary of the Trenton 
formation can be found in the type section. The shaly layers 
following the pure crystalline limestone in other localities and 
forming the transition to the Utica are not represented. 
TRENTON LiMEsTONE in the Kauya Hoora gorge section %on- 
sists of: 
Upper: Heavy, bedded, gray, coarse crystalline. 
