1896.] BUTTHRFLINS OF THE FAMILY HESPERIID®. 3 
precious types of Hewitson and other great naturalists, who have 
placed their collections in the care of the institution. 
In following up my labours I have been greatly aided by the 
possession of a large mass of well determined Indian material, 
which I have been accumulating for many years past, and particu- 
larly by the possession of the Knyvett collection, for which 1 am 
indebted to the generous kindness of Mr. Andrew Carnegie, my 
distinguished fellow-townsman, whose interest in all things relating 
to the advancement of science is well known. I have derived 
much assistance from the collections which I have received from 
Mr. William Doherty, the well-known naturalist explorer of the 
far East, and from the collections for which I am indebted to Mr. 
L. de Nicéville, of Caleutta, whose great work upon the Lepidoptera 
of India is a monument to his painstaking diligence and scientific 
acumen. I am no less indebted to Mr. Roland Trimen, the late 
learned Curator of the South-African Museum at Capetown, whose 
labours upon the fauna of extra-tropical Africa are classic, and who 
with the most engaging kindness has presented me with authenti- 
cally determined specimens of most of the species named by him. 
It is much to be wished that all authors might acquire those habits 
of exact observation and clear description which are possessed by 
this Nestor among lepidopterists, whose diagnoses of the various 
species contained in his last work upon the Butterflies of South 
Africa are so exact as almost to make the work of pictorial repre- 
sentation superfluous. Iam under yery special obligations to the 
authorities of the British Natural History Museum not only for 
permission to freely study the collections in their possession, but 
for permission to have drawings made of the hitherto unpublished 
types of the late Mr. Hewitson and of Dr. Butler. I have to 
thank Dr. Karsch of the Berlin Museum, and Dr. Rogenhofer of 
the Imperial Museum at Vienna, for similar kindnesses. From 
Mons. Mabille of Paris I have received most distinguished 
courtesies, and I am indebted to him for the opportunity to ex- 
amine personally the types of many of his recently described species, 
and for the use of a number of copies of the unpublished figures of 
Ploetz. Ploetz made no collection of specimens during his lifetime, 
but contented himself with making drawings, not always very 
accurate, of the species which he described in the collection of 
others, or which he found figured in various works. These figures 
are in many cases our only safe clue to a knowledge of the species 
he named, for his descriptions are in many instances very unsatis- 
factory. I cannot fail in this connection to express my indebtedness 
to Lieut. Watson, who compared many of the species in my 
collection with the types in the British Museum, and assigned 
them to the respective genera to which they belong in his classi- 
fication, and to Dr. Butler and Mr. Herbert Druce for their 
generous assistance at all times freely given. Among American 
entomologists, I am especially indebted to Dr. S. H. Scudder of 
Cambridge, who, upon the occasion of his last visit to Europe, did 
me the great fayour of comparing a series of drawings of Eee species 
1 
