NOTES ON THE FLORA OF DERBYSHIRE 201 
Y. The so-called Yoredale Series lies between the Grits and 
the massive Carboniferous Limestone formation. The applica- 
tinguished from that of the Limestone has been but slightly 
worked in detail. We are able, however, to give a few notes on 
this system. 
L. The Carboniferous Limestone formation is too well known 
to need any description. Its flora is very characteristic. 
The Triassic formation of the south of Derbyshire has not been 
worked by us. 
re is one aspect of the subject which we cannot allow to 
pass unmentioned. I 
tre 
limits of the county itself, in most respects a purely arbitrary area, 
often quite without reference to geological or physical considera- 
tions, is very obtrusive. The small Permian area on the east of 
the county is really only a small portion of the extensive Permian 
i esses a flora 
a whole. 
The Coal Measures of the north-east, again, form part of the 
great South Yorkshire and North Derbyshire Coal Field, and the 
flora of the whole area of the district ought to be considered and 
ae i 
tracts of South Derbyshire. At the same time, the careful an 
detailed working of County Floras and the publication of many 
records and localities will enable us eventually to complete a flora 
of each natural geological district irrespective of county boun- 
daries. When each district has been treated in this manner a 
natural presentation of the distribution of each species throughout 
the British Isles will have been given. 
