PREFACE, 



The publication of this Catalogue of British Non-parasitical Worms 

 has been delayed, owing to the lamented death of the author, 

 Dr. Jom^rsTON, while it was still in the Press. A Supplement, pre- 

 pared by Dr. Baird, containing addenda, corrigenda, and a notice of 

 additional species found since Dr. Johnston's death, with a complete 

 index, have been added, to render the work more complete. 



J. E. GRAY. 



8th February, 1865. 



