16 
the sharpest possible contrast faunally with the blue shale, c, above, 
not a single species being common to both. The two formations are 
separated by an angular unconformity which is clearly shown at a number 
of points along the cliffs. The basal Devonian clays may lie 75 feet 
above the river in one section and in another a few yards away be found in 
place, 50 feet lower. The cliffs show good vertical sections of cistern and 
well-shaped chimneys 50 to 65 feet deep filled with Devonian clay and 
shale rich in fossils, which evidently represent ancient caverns in the 
gypsiferous shales and associated limestones. The photograph (Plate II, 
figure 2) shows the relations existing between the two sets of unconfor- 
mable beds found in these cliffs. The blue shales with thin calcareous 
bands overlying the Silurian beds and characterized by the fauna listed 
below will be called the Peace Point beds. 
The beds, d, are believed to correspond in horizon to the upper beds 
of the Silurian limestones of Manitoba east of lakes Manitoba and 
Winnipegosis. Their equivalent beds in the New York section probably 
lie within the limits of the Cayugan group. 
DEVONIAN FAUNA 
The Devonian blue clay and shale (e of section, page 15), with its asso- 
ciated thin-bedded limestone bands which overlie the Fitzgerald beds, 
contain an abundance of fossils in a perfect state of preservation. The 
following species are from these beds. This fauna is considered to represent 
an early phase of the Upper Devonian fauna. 
Fossils Collected at Stations S and 4 From the Devonian Shales of the Peace 
Point Section 
Crinoid stems e 
Aulopora cf. adnascens Fenton r 
Spirorbis omphaloides Goldfuss. c 
Crania sp r 
Schizophoria atriatula (Sehlotheim) c 
Camarotoechia sp r 
Pttgnax pugnm Martin var c 
Leiorhynchus niesacostale Hall c 
Atrypa reticularis (Linn.) a 
Airy pa ef. spino&a Hall r 
Cyrtina hamiltonensis Hall var, r 
Cyrtina billingsi Meek o 
“ “ var. symmetrica n. var r 
Spirifer tullia var, Whiteaves e 
Palaeoneila fdosa (Conrad)....* r 
Leda cf. diversa (Hall) r 
Modiomorpha sp. undet r 
Leplodesma cf, naviforme Hall r 
Correlation of the Fauna 
Comparison of this fauna with the rich Devonian fauna collected from 
the Peace River section at the Chutes, 150 miles above the Peace Point 
cliff section, shows only one species in common, the ubiquitous Atrypa 
reticularis, Spirifer disjundus, which is extremely abundant in the upper 
Devonian faunules at the Chutes, in the Hay River section, and at other 
points in the late Devonian of Mackenzie River district, is unknown in 
the Peace Point section. The absence of this significant species suggests 
