IV. INTEODUCTION. 



rough sheets for all the species recorded with the exception of 

 the Pterophorids), wheri, owing to the state of his health, he in 

 Decemher, 1910, sent to the Council of the Society the following 

 letter : 



" "With reference to the concluding volume of the Rohson 

 Catalogue of Lepidoptera of Northumberland and Durham, it is 

 with the greatest regret that I write to ask if your Council will 

 kindly relieve me of my undertaking to edit the volume in 

 question and see it through the press. 



" As you know, I have been hoping for a long time past that 

 my health might be sufficiently restored to enable me to carry 

 out my promise, but I fear that this is not to be, for the 

 temporary improvements that have taken place now and then 

 have not been maintained, and I am now suffering from 

 another nervous breakdown. This necessitates complete rest 

 and change, and I am therefore leaving home next week. 



" During Mr. Robson's lifetime I supplied him with my 

 critical notes on the whole of the manuscript that he had pre- 

 pared for the volume (which manuscript was complete except 

 for the Pterophorids, and Mr, J. Gardner has since supplied the 

 omission). He did not live to make use of these notes, but 

 they are available for anyone who sees the work through the 

 press. 



"Mr. J. Gardner is a lepidopterist and much interested in the 

 completion of the Pobson Catalogue. I have not of course 

 approached him on the subject, but perhaps he would be willing 

 to undertake the work if your Council saw fit to ask him." 



The Council, acting upon Mr. Bankes' suggestion, invited me 

 to undertake the work, and under the circumstances I felt that 

 I could do no less than accede to their request. 



It might seem from the foregoing that there remained now 

 very little to do but to place the manuscript in the printer's 

 hands. I found, however, that there was a great deal more to 

 do before this could take place. In the first place, as before 

 stated, a few sheets had already been printed off but not 



