150 
the parent bed, while the great dyke in which they are en- 
closed was in a molten condition, and that they either sank 
of their own weight to the low position they now occupy, 
or that they were drawn down during the surgings of the 
intrusive [3]. 
The breccia also contains pebbles of limestone with 
Trenton fossils, and there are other and smaller pebbles 
with lower Devonian faunas. Some of these pebbles have 
weathered out, and may be found loose along the shore, 
especially on the northern and western sides of the island. 
OTTAWA AND VICINITY. 
HULL. 
Trenton Limestone and the Cement Works.—On leaving 
the Hull electric station in Ottawa the massive limestone of 
the uppermost division (sponge beds) of the Trenton can 
be seen in the cliffs on the right. The same strata are 
seen in the cliffs above the level of the floor of the In- 
terprovincial bridge, and contain the sponge and Hor- 
motoma trentonensis fauna, while the strata below this 
level belong to the cystid zone and carry Pleurocystites. 
From the bridge itself can be seen on the one hand 
the strata of which Parliament hill is built, and on the other 
the cliffs of Nepean point and other bluffs down the river. 
The shore on the Hull side is low with no rock exposed. 
At the Axe Factory quarry in Hull the contact between 
the massive beds of the Tetradium zone of the Trenton and 
the thin shaly beds at the base of the Prasopora zone is 
well shown. A fault crosses the floor of the quarry, which 
lets the strata on the eastern side down about 15 feet 
(4-5 m.), thus repeating the shaly layers. The shaly 
layers are very fossiliferous, and this locality has furnished a 
great variety of fossils, among them the type of Bumastus 
billingst. The common fossils still to be found are Praso- 
pora, several species, Zygospira recurvirosiris, Dalmanella 
rugosa, Plectambonites sericeus, Parastrophia hemiplicata, 
Ctenodonta levata, Calymene Senaria, and others. 
North of this quarry is another situated in the angle 
between the two railroads. The beds here are about 25 
feet (7-6 m.) lower stratigraphically than those in the Axe 
Factory quarry, and belong to the crinoid zone. This 
quarry has furnished a large number of crinoids, but 
