viii 
INTEODrCTION. 
have myself met with or recognized, and which have not before been recorded as 
occurring in that country. 
Mr. Edwin Wilson has exercised great care and patience in faithfully render- 
ing the form and markings of the various specimens. In the case of some of 
Mr. Walker's types, which are in extremely poor condition, this has been a difficult 
task ; but the measure of success with which it has been accomplished will, 
I trust, be the means of preserving a reliable record of this portion of Mr. Walker's 
work. 
WALSINGHAM. 
