135 
In this communication the author gave a little more infor- 
mation which he had lately obtained in a line from Hoghton 
Tower to Fleetwood ; also at Cockersand Abbey, south of 
the mouth of the Lune, and Robshaw Point and Heysham 
to the north of the same river ; and made a few remarks on 
some singular red sandstones hitherto classed as trias in the 
neighbourhood of Whiston, Huy ton, Knowsley, Croxteth 
Park, and Rainford, and laid down as such on the maps of 
the Geological Survey. 
No doubt it is a very difficult matter to determine with 
absolute certainty where the trias strata end and the pcrmian 
begin, when there are no organic remains to guide us and 
we have to trust to a bed of red marl or a deposit of red sand- 
stone. In the author’s several memoirs published on this 
subject, so far as South Lancashire was concerned, the red 
marls and limestones of Newtown and Bedford are assumed 
to be the uppermost permian deposits found. It is quite true, 
as stated in his third memoir — “ Some of the sections near 
Manchester, especially that seen in the valley of the Irk in 
Cheetham and Newtown, would apparently show that the red 
marls containing limestones and fossils of the genera Bakevellia, 
Schizodus , &c., passed into the overlying trias ; ” but as a whole 
it was assumed from other facts that the red sandstone of the 
trias was unconformable to the underlying permian beds. In 
a paper published by Sir R. I. Murchison and Professor 
Harkness, printed in the Quarterly Journal of ilie Geolo- 
gical Society for May, 1804, as well as in the author’s last 
memoir, the thick red sandstones of St. Bees are described as 
permian and not as trias, and were traced down, as Professor 
Sedgwick had previously followed them, into Furness near 
Ilowcote and Barrow. Anyone who sees the red sandstones 
much used for building purposes at Shawk, Maryport, and 
St. Bees, and compares them with that at Howcote, will not 
be able to distinguish the one from the others. It is only from 
their physical characters that we can compare these sand- 
