154 
Similar holes have since been found by Mr. Salter, F.G.S., 
in rocks of various ages, from the Cambrian upwards, and 
that distinguished palaeontologist has called them arenicolites. 
The position of the Kerridge flags is, probably, one of the 
best ascertained in the whole coal field. It is in the lower 
division above the millstone grit. In his lower coal field he 
gives two main beds of flagstones : the first or lower, the 
Rochdale series, under the rough rock ; and the upper, or 
Upholland or Kerridge series, above the same rock, the chief 
workable beds of the lower coal field of Rochdale and other 
districts, often termed the “ mountain mines,” lying midway 
between these two flag deposits. This series of coal is now, 
and has been for many years, wrought under the Kerridge 
flags, so as prove beyond doubt the position of the latter. 
Some discussions have lately taken place in the newspapers 
at Macclesfield as to whether the Kerridge beds were per- 
mian or carboniferous. No one, who ever saw permian beds, 
could ever for one moment suppose Kerridge flags to belong 
to those strata. It is possible that permian beds may exist in 
the low district lying between Kerridge and Macclesfield, as 
they have been met with at Hug Bridge on the south, and 
Norbury Brook on the north, but up to this time they have 
not been proved to be there. 
Considerable interest has been excited by the discovery of 
what were supposed to be the foot-marks of some animals on 
the surface of the flags. He had been induced to make two 
journies to Kerridge for the purpose of examining them. 
Once he found two ripple marks pressed into one, which some- 
what resembled a human foot, and which was shown to him 
as the mark of one ; and at another time he was shown what 
was called a track of some animal, but which was evidently 
no track at all, but most probably made by running water. 
Although plenty of worm holes and ripple marks are to be 
found on the surface of the Kerridge flags, as yet he had seen 
no tracks of animals upon them. 
