254. BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
green, yellow, and brown sandy and calcareous shale, and in sand- 
stone in the Lorraine (Pulaski). 
When the Trenton is traced northward from Trenton Falls it is 
found well exposed along the tributaries entering the Black River 
from the west. In this region the Cryptolithus bed is no longer seen 
at the base of the formation, but the middle beds with Prasopora 
simulatriz are the same as at Trenton Falls. At the top, however, a 
considerable thickness of strata are added, of a kind not seen at 
Trenton Falls, and containing a fauna not found there. Above thin- 
bedded limestone containing Rafinisquina deltoidea, these beds being 
the equivalent of the upper strata at Trenton Falls, one finds thick- 
bedded impure dark gray limestone which on weathering breaks down 
into a rubbly mass. This limestone contains many gastropods and 
some other fossils, the most characteristic being Hormotoma trentonen- 
sis, Fusispira subfusiformis, and Cyclospira bisulcata. 
It is interesting to note that the species which are most characteristic 
of the upper beds and most of which are not found at Trenton Falls, 
were described originally from this region. Thus the type-localities 
of Fusispira subfusiformis are Adams, Jefferson County, where only 
these upper beds are exposed, and Turin, Lewis County. Trocho- 
nema ambigua, Fusispira vittata, and Cyclospira bisulcata were all 
described from specimens obtained at Adams, and Holopea paludini- 
formis and Subulites elongatus were both found originally in the higher 
Trenton strata at Watertown. Of all these species, only the last has 
been found at Trenton Falls, and in New York they are characteristic 
of strata above the strata exposed at Trenton Falls, and the highest 
Trenton limestone exposed in the State. 
ONTARIO. 
Crossing into Ontario, the section is practically identical with that 
in northern New York, except for certain loca] developments. The 
strata in the middle of the Trenton remain the same as those at Tren- 
ton Falls, but the lower beds do not carry Cryptolithus. The lower 
beds do, however, show a decided recurrence of Black River conditions. 
and faunas, as high as 100 feet above the base of the formation, so that 
there is here practically continuous sedimentation after the Leray, the 
Trenton fauna gradually replacing the Leray fauna. In this respect 
the section reminds one greatly of Kentucky, as will be seen later. 
The section, in descending order, is as follows, the section at Ottawa 
being taken as typical of the region. 
