Ft. In. 1. Crawstone Measure Crust 1 8 2. Rock 10 6 3. Coal Smut 0 9 4. Clunch with balls of Sandstone 12 0 5. Lancashire Ladies’ Coal 0 6 6. Strong Clunch with Sandstone balls 19 0 7. Sandstone Rock 10 6 8. Chalkstone 12 0 9. Limestone (Silurian) 28 6 Total 95 5 This then may be considered a fair representation of the remainder of the measures which occur below those seen on the surface at the Black Rock Quarry; but the passage from the carboniferous to the Silurian formations is _no where conformable_, and no mention is made of the Millstone grit, a portion of which certainly intervenes, and which is to be seen in small patches near, but which might possibly be represented by the three or four last measures in the section of the Lincoln Hill Limestone Shaft. Excellent opportunities occur in this immediate neighbourhood of studying the junction of the Silurian and Carboniferous formations, and of the evidences afforded of the denudation of the one prior to the formation of the other. To the general reader these words may convey little meaning, but the scientific student who studies the evidences here made clear cannot fail to comprehend the fact that he has before him not only an old sea-bed, rich in relics of the fauna which inhabited its waters, but a sea-bed which had become a cliff, and had in turn been gradually cut down and wasted during successive ages prior to that at which a carboniferous flora had begun to flourish. Two series of rocks are here in juxtaposition, yet so widely separated by time, as to indicate a gap in the consecutive history of the earth as great as if we were to blot out the intermediate history of this country from the close of the Heptarchy to the reign of George III.; only that the period of time in the latter case would bear no manner of comparison with the former. If we suppose the Wenlock limestone to have been once covered at these points by the Ludlow limestone, and this again by the old red sandstone—as is the case to the south, to say nothing of the carboniferous limestone and millstone grit, we are forced to the conclusion that thousands of vertical feet, and hundreds of cubic miles of solid ground were first piled up and then cut down and carried away by the sea. Creation itself in the interval of their formation passed through many phases, during which new species came slowly into being and disappeared, and were again replaced by others. To fill up the gap that succeeds this great silurian flooring of the coal-measures, to study the intermediate links of the missing strata we