ADDITIONAL SPECIES, ETC. 311 



{Second Part of Volume Third). 



1. ADDITIONAL SPECIES, &c. 



The first volume of this work was written in 1846, and 

 much of it also printed in the same year. Between that 

 date and the early months of 1853, in which this latter 

 portion of the third volume is now printing, several addi- 

 tional species have been discovered in Britain. In other 

 instances, familiar species have been subdivided ; so that 

 they now appear in descriptive Floras as two different and 

 distinct species, although formerly described and named 

 as a single species only. The geographical distribution 

 of these added or subdivided species, and also of some 

 other imperfectly treated species that are now better 

 known, will of course require to be shown in the same 

 manner as that of the other species, in order to provide 

 data for any after numerical or statistical summaries, and 

 in order that such summaries may be thus rendered as 

 nearly complete as existing information will allow. 



Further, new localities have been ascertained for many 

 other species, which wiU require some corresponding al- 

 terations in their formula of distribution, as set forth in 

 the preceding volumes. And various doubts and ques- 

 tions have been more or less clearly answered and settled 

 by an increase of knowledge bearing upon those points, 

 during the past half-dozen years. These circumstances 

 have rendered it desirable, and almost necessary, to intro- 



