Notes and Comments. 153 
the neighbouring country of Craven which he had previously 
examined, and that they were different in species and in associa- 
tion from the fossils found in the ordinary bedded limestones. 
The deduction is obvious that they represented a fauna which 
regularly adopted the knoll form of growth, and could not 
possibly have been squeezed out of other beds in the manner 
postulated by Dr. Marr. Such a triumphant vindication of 
Mr. Tiddeman’s original suggestion was the chief interest of 
the excursion on the Carboniferous side. <A further piece of 
evidence in support of the knoll theory was the discovery in 
the limestones of the Knott, near Knowlmere, of little beds of 
tufa. Tufa is derived from the deposition of limestone from 
solution practically by evaporation. Assuming that these 
little patches were the floors of lagoons and pools in the reef 
their presence is easily intelligible. It would be difficult to 
explain them on any other basis. 
INGLEBOROUGH AND BOWLAND LIMESTONES. 
Incidentally some attention was given to another problem 
of the locality which has been also hotly contested. Mr. 
Tiddeman noticed, when he surveyed the district, that the 
limestones in the Bowland district were extremely different 
from those of Ingleborough, and that the mud-stones (shales) 
lying upon the limestones in the two areas were also very 
distinctive. He quaintly compared the rocks of the two areas 
to the Jews and the Samaritans, who agreed in nothing but a 
common boundary and the determination to have nothing to 
do with one another. The geological boundary in the Yorkshire 
case he found to be the great Craven fault, that dislocation 
which formed the impressive wall of limestone rocks from near 
Skipton round to Ingleborough and beyond. It has been 
found by Mr. Cosmo Johns that part of the difference at least 
which Mr. Tiddeman found in the Ingleborough and Bowland 
limestones arose from the fact that they are not precisely 
contemporary. But difficulty has arisen with regard to the 
shales which form the upper part of both Ingleborough and 
Pendle. Dr. Wheelton Hind, writing on similar evidence of 
fossils, came to the conclusion that, similar as the great York- 
shire and Lancashire heights are in structure, there was a great 
diversity in their age, for he found evidence for the belief that 
the Pendleside series—as they have been called—are of later 
date than the Yoredales of Ingleborough and North Yorkshire. 
INVESTIGATION OF YORKSHIRE RIVERS. 
The drainage system of Yorkshire places it in a unique 
position among the counties of England for carrying out a 
systematic research upon its water resources, and the Yorkshire 
Geological Society has decided upon setting such an enquiry on 
foot. The aims and scope of the work are set forth on a leaflet, 
1915 May 1. 
