The Fossil Plants of the Coal Measures. 57 



have a practical value. So far as the above six memoirs 

 are concerned, any future students can know where to find 

 the originals of the figures and descriptions therein published. 

 The obvious advantages afforded by such a record of the 

 location of some of my type-specimens made it desirable 

 that the method should somehow or other be extended to 

 the other specimens described in all my earlier memoirs, 

 and the preparation of this Index has made the realisation 

 of this object easy. Throughout its pages, the symbolic C.N., 

 with its appropriate number, will be associated with nearly 

 every figure and description quoted. Ere long, as is well 

 known, my cabinet and its descriptive catalogue will find their 

 permanent resting-place in the Botanical Museum located at 

 the Owens College, where it will be accessible to Palseo- 

 botanical students in all future time. Hence, such students 

 will have no difficulty in examining for themselves the facts 

 upon which my various hypotheses have been based, as well as 

 in testing the accuracy or otherwise of my figures and 

 descriptions. But I have further availed myself of the 

 opportunity afforded by the publication of this Index to 

 remedy some other defects and omissions in the original 

 memoirs. Thus in some of the earlier publications no pro- 

 visional names were attached to the type-forms figured. 

 There was also, in some cases, a want of a more condensed 

 definition of those types. In some other instances suggestions 

 were made which my later investigations have failed to 

 sustain. I have also neglected in several cases to indicate 

 what names of the types emanate from myself and what 

 have been adopted from other writers. Most of these 

 defects will be remedied as my present work proceeds. The 

 whole will, I trust, not be without some little additional 

 influence in advancing our knowledge of Palaeo-botanical 

 Science. 



