PREFACE, xili 
century, and which is to be found under the letter H, in Jerdon’s 
Birds of India, Blyth’s Catalogue, Bonaparte’s Conspectus, and 
the Proceedings of the Zoological Society of London down to 
1865. Classicists now write Henicurus as the correct form ; 
but this seems to me one of those cases in which orthographical 
accuracy should give way to priority, and still more to con- 
venience. 
In combining and arranging so much detail from such varied 
sources, many errors and omissions must doubtless have occurred. 
Owing to my residence at a distance from the scientific libraries 
of the metropolis, I was placed at a great disadvantage; and I 
could hardly have completed the work at all, had I not been 
permitted to have a large number of volumes at once, from the 
library of the Zoological Society of London, and to keep them 
for months together ;—a privilege for which I return my best 
thanks to Mr. Sclater the Secretary, and to the Council. 
Should my book meet with the approval of working natu- 
ralists, I venture to appeal to them, to assist me in rendering 
any future editions more complete, by sending me (to the care of 
my publishers) notes of any important omissions, or corrections 
of any misstatements of fact; as well as copies of any of their 
papers or essays, and especially of any lists, catalogues, and 
monographs, containing information on the classification or 
distribution of living or extinct animals. 
To the many friends who have given me information or 
assistance I beg to tender my sincere thanks. Especially am I 
indebted to Professor Newton, who not only read through much 
of my rough MSS., but was so good as to make numerous cor- 
rections and critical notes. These were of great value to me, as 
they often contained or suggested important additional matter, 
or pointed out systematic and orthographical inaccuracies. 
