132 ROYAL SOCIETY OF CANADA 
holding phosphatic nodules, both of which series are capped by marine 
limestones holding in many localities innumerable quantities of ostra- 
coda eminently characteristic of this formation. The entire formation 
is not more than 200 feet in thickness in its greatest development, and 
passes upward insensibly into the Black River formation. At Rock- 
cliff, near the terminus of the Ottawa Electric Railway, at Hogsback, 
and Skead’s Mills and Britannia, in the township of Nepean, at Moore’s 
Landing near the Chats Falls, and at Aylmer, at Fairy Lake and Hem- 
lock Lake, the Chazy formation may be studied to advantage. A care- 
ful search will no doubt reveal many new and hitherto undescribed 
fossil remains from the Chazy. 
The conditions of deposition which prevailed during the time when 
the upper, calcareous, beds of the Chazy formation were laid down, con- 
tinued on during the whole lapse of time covered by this formation 
and accordingly the limestones of the Chazy pass imperceptibly into the 
limestones of the Bird’s Eye and Black River formation. 
Black River formation.—These strata are more uniform in texture 
and composition than those of the Chazy, and although there exists no 
stratigraphical break in the succession of the beds or unconformity, still 
there has been noticed sufficient difference in the fauna entombed in 
the limestones of the Black River formation to distinguish it from the 
fauna of the Chazy. This difference has been possibly too much em- 
phasized by some geologists; it is a remarkable fact however, that the 
fossil organic remains of both formations. have but few species in com- 
mon. ‘The conspicuously prolific bed of ostracods which occurs at the 
summit of the Chazy seems to be a good dividing line between the 
typical Chazy and the Black River above, leaving a few strata between to 
form a transition series. The more characteristic species of fossil organic 
remains occurring in this formation about Ottawa are :—Tetradium 
jibratum, Safford ; Columnaria Halli, Nicholson ; Séromatocerium rugo- 
sum, Hall; Streptelasma profundum, Hall; Calapecia Canadensis, Bil- 
lings; Lophospira helicteres, Salter; Gonioceras anceps, Hall; Bathyurus 
extans, Hall. For a more complete list of the species, occurring in this 
formation, in the Ottawa Valley, see paper by the writer in Trans. 
Royal Society of Canada, Vol. 2, series 2, Section IV., pp. 153-154, 1896. 
The Black River formation is best seén along the shores of the 
Ottawa River, at the Petite Chaudiere Rapids, on the Ontario side, 
above the C. P. R. bridge, Hull side ; near City View Post Office, Meri- 
vale road ; at the Central Experimental Farm ; near Hogsback, north of 
Aylmer, and in the vicinity of Beechwood Cemetery, south of the great 
fault or dislocation near the entrance to the cemetery. At Rockland, 
the upper beds of this formation have been quarried for canal purposes, … 
\ 

| 
| 
