500 LOCAL SECTIONS 
A mile below the mouth of Miniskah River, another Trilobite bed, lower strati- 
graphically than that of La Grange Mountain, is seen, just above the talus of rub- 
bish and loose rock, at an elevation of one hundred and seventy-three feet above 
the water. 
This Trilobite grit is slightly micaceous, and of a light greenish-gray colour; its 
thickness is about three feet, and the layers are thinly laminated. Besides several 
species of Trilobites, it has yielded one small species of Orthis, and two species of 
Lingulas. One layer contains those remarkable spines, belonging to a curious 
species of Trilobite, in the shape of a fish-hook. The most common species is the 
one we have hitherto designated as the Miniskah Trilobite. A third species also 
occurs here, much smaller than either of the others, its cephalothorax scarcely ex- 
ceeding two lines in length. 
Over the Trilobite grit are ninety-three feet of sandstone, the lower beds of which 
are thinly laminated, and of green and yellow colours. The upper are thicker, and 
have intercalations of magnesian limestone. On this reposes ten feet of ash- 
coloured argillo-caleareous layers, containing Dikelocephalus Minnesotensis; the 
whole surmounted by soft brown and yellow sandstone, containing Lingulas. 
The Great Slide, about five miles below the mouth of the Miniskah, shows a 
very instructive section of many of the members of F. 1. 
1. The talus at the foot of the bluff conceals the beds belonging toF.1,¢, . 6 
2. Green, and soft green sandstones, with scales of mica, : ie 4 
3. Brown calcareous rock, . : 4 
4. Layers of green sandstone, alternating with green saints, ; ; es i. 
5. Micaceous sandstone with Trilobites, : ‘ ‘ P ‘ 2 
6. Alternations of green and ferruginous sandstone, . ‘ . i ae 
7. Micaceous sandstones, with Dikelocephalus Miniscaensis, — . : : 3 
8. Loose green sand, and soft green sandstone, : ‘ : eae i 
9. Thin seam of greenish blue earth. 
10. Laminated green and yellow sandstone, 38 
11. Concretionary green, red, and yellow siietaie, wits dlicsie of iron aoe 
minated, 3 
12. Green, red, and vied pM Bes Ree a nie ‘Arete en passing 
downwards into brown Orthis, and encrinital siliceo-caleareous rock, 44 
13. Yellow and ash-coloured argillo-caleareous rock, containing Ditelocephatn 
Minnesotensis, and another species of Trilobite, 
14. Alternations of thin-bedded and light brown and bluish mndainbé: 
15. Thick beds of soft yellowish sandstone, with hard, botryoidal sonetinee 
passing downwards into light-coloured, fits preted sandstone, 51 
16. Mammillary and botryoidal layer of white sandstone banded with vellnie 8 to 4 
17. Quartzose sandstone, with intercalations of magnesian limestone, with glisten- 
Oo © 
ing crystalline facets, . ; ; : ‘ ‘ ne 88 
18. Lower Magnesian Limestone, ‘ ; s : : Peoge 
525 
The next locality, “ Mountain Island” (La Montagne qui trempe a Teau), exhibits 
several of the lower beds of F. 1, in connexion with most of the preceding, and is 
perhaps the best connected section of the stratification of F. 1 to be found on the 
