PREFACE. 
but imperfectly explored, and it is very probable that some additional 
plants and many new localities will reward well directed enquiry. 
Even while the last sheets were passing through the press, Mr. 
Gibson, Dr. Lankester, and Mr. Moore, furnished Addenda which are 
introduced at the end of the Catalogue. 
The rare Schistostega pennata has also, during the last month, 
been added to the List of Mosses, by Mr. John Nowell and Mr. John 
Howarth, of Todmorden. 
That many more curious discoveries remain to gratify the diligent 
Botanist who ventures beyond the ordinary road into the more secluded 
districts of Yorkshire, can scarcely be doubted, and perhaps the present 
record of localities of known plants may in some degree contribute to 
stimulate research. Having used all the means and exertions in his 
power to furnish a faithful guide to the present amount of knowledge, 
the Author trusts that reasonable allowance will be made for any errors 
or imperfections which may be observed in his work ; and he hopes that 
the numerous friends without whose aid it would have presented a very 
different appearance, will still continue their kind attention, and by 
correcting and improving the Catalogue now offered to their notice, 
gradually render it a complete representation of the rich Flora of 
Yorkshire. 
yWc, September \st^ 1840, 
