368 THROUGH UNKNOWN AFRICAN COUNTRIES. 
CON GL USTON: 
W* arrived in England on the last day of November, 
‘V 1895, after an absence of a year and a half. 
Before concluding my narrative, I wish to express my 
high appreciation of the interest which the various special- 
ists who have described my collections, and many of whose 
names appear in the appendices to this book, have taken 
in my work. And I wish also to thank the English ofh- 
cials at Aden, and the United States Consul at that port, 
William M. Masterson, Esq., for their courtesies and their 
many acts of kindness toward me. I have presented 
almost all my natural-history collection to the above- 
mentioned specialists, or else to the institutions with which 
these gentlemen are connected, — the British Museum of 
Natural History receiving most of the type specimens 
of new species, and the Academy of Natural Sciences, 
of Philadelphia, the greater part of the remainder. 
My maps I have presented to the Royal Geographical 
Society, of London, and I am greatly indebted to E. V. 
Ravenstein, Esq., cartographer of the society, for the care- 
ful and excellent way in which he has compiled them. 
The five maps which accompany my narrative are copied 
from drawings which I made during my journey, and are 
based on many hundred observations which I took with 
theodolite, sextant, and prismatic compass. 
In reference to the large number of species of birds, 
reptiles, mammalia, etc., new to science, which my natural- 
history collection contains, and in regard to the value of 
the collection as a whole, I will refer readers to the appen- 
dices to this narrative, and to reports which have appeared 
in the Proceedings of the Zodlogical Society of London, 
