Vlll PREFACE. 



Council has now honoured me by determining on this 

 publication, so that these species will hereafter be more 

 fully illustrated than they could be in the present volume. 

 I cannot conclude this short preface, without again tender- 

 ing my most grateful thanks to the Council of the Ray 

 Society for the publication of my two volumes, and for the 

 very kind manner in which they have acceded to all my 

 requests. 



Down, Kent; July, 1854. 



