PRÉFACE 20 
duction, page IX : « An important point for the satisfac- 
tory progress of our work was a comparison of the long 
series of types of Walkers and Boisduvals descriptions, 
contained respectively in the magnificent collection of 
Mons. Charles Oberthür and in the British Museum. 
À closer study of these specimens than had hinterto been 
attempted was absolutely necessary. For Boisduval when 
visiting the British Museum in the forties of the lost cen- 
tury, has named in manuscript and made notes upon the 
Sphingidæe of that collection, which names were for the 
greater part adopted by Walker in 1856, but often applied 
to other species than those for which Boisduval has intended 
them to stand. This muddle became intensified by Bois- 
duval, who, in his Monograph published in 1875, gave 
descriptions taken from his own specimens and applied the 
before-mentionned manuscript names to species which he 
beheved to be the insects he had named in the British 
Museum, but which were often not the same. Moreover, 
Boisduval failed to recognise many of the Walkerian spe- 
cies, and described them again under new names. The 
confusion thus occasioned has, we hope, been successfully 
cleared up in the present Revision. » 
Je pense qu'on peut traduire les observations ci-dessus 
relatées comme suit : 
« Une chose importante pour que notre ouvrage ne 
laissât rien à désirer, c'était la comparaison du grand 
nombre de types des descriptions de Walker et de Bois- 
duval, contenus respectivement dans la magnifique collec- 
tion de M. Charles Oberthür et dans le British Museum. 
Une étude de ces spécimens plus serrée qu’elle n'avait été 
tentée jusqu'ici, était absolument nécessaire. Quant à Bois- 
