205 
[Marcou. 
1891.] 
ravine in a great V shape, which is most interesting to study, be- 
cause we have there the remains of a landslide in the form of a 
spindle (fuseau in French) , which has preserved from destruction 
a part of the Upper Trenton and Utica formations, in a sort of box 
situated between the almost perpendicular wall of quartzites and 
the gray and brown slates of the Upper Taconic. At a distance 
of only ten yards from the eastern part of the foot of Montmor- 
ency fall, we have the following section. Fig. No. 3. 
The section begins at the top of the plateau a few yards east of 
the fall, then cuts the ravine perpendicularly going through the 
hill of slates which extend directly to the river St. Lawrence. 
The section is parallel to the preceding one (fig. No. 1) at a dis- 
tance of only thirty or forty feet eastward. 
At the top of the plateau we have fifteen feet of the Black river 
or Upper Trenton limestone, exactly like the fifteen feet of the 
section (fig. No. 1) near the bridge. The fossils are abundant ; and 
the moulding of the thin strata of limestone over the inequalities 
of the heavy beds of the quartzite are conspicuous at the contact 
of the two rocks. Then we have the almost perpendicular wall of 
quartzite, with a dip of 85 degrees. At the bottom of the ravine, 
there is an intermittent creek, which falls from the Trenton lime- 
stone above and flows during several months of the year. When 
dry, the lowest rocks seen belong to the quartzite ; then we have 
about twenty feet of blue-black Upper Trenton limestone, with a 
dip of only ten degrees south-south-east ; then come above it six- 
teen feet of gray slates and two feet of blue limestone with a dip of 
20 degrees ; then thirty-five feet of brown and gray slates with a 
dip varying from thirty to forty degrees. In those seventy-three 
feet of limestone and slates the fossils are abundant, and accord- 
ing to Mr. Henry Ami, paleontologist of the Canadian geological 
survey, they indicate a fauna “pre-eminently Utica in facies, with 
an evident admixture of a few Upper Trenton species obtained 
from the lowest calcareous beds which crop out in the ravine.” 
Here is the list of fossils collected and obtained by Mr. Ami : 
Primitia , Triarthrus Becki ? Calymene Bhimenbachii, Illaenus, Or- 
this testudinaria , Leptaena sericea, Leptobolus insignis and Lingula. 
At the contact of the brown slates of the Utica formation, and 
the black slates of the Quebec city group or Swanton slates, there 
is great disorder and confused stratification ; the dip of forty de- 
grees passes rapidly to the vertical and is even reversed ; some 
