PREFACE. 
XIX 
considerable collection of casts and remains of non-Indian fossil vertebrates, but these 
really comprehend only a few of the better known genera.^ Thirdly, although the 
library of the Geological Survey is an extensive one, there are wanting a great 
number of the older works on vertebrate palaeontology, many of which are now out 
of print : in many cases, moreover, works, when ordered from England, arrive in India 
too late for the purposes of the worker who required them. Fourthly, the student in 
Indian vertebrate palaeontology at the present time labours under the great disad- 
vantage of working without the possibility of appealing to other workers in the 
same branch of study for assistance and advice in cases of doubt and difficulty. 
There are also wanting in the zoological department of the Indian Museum skulls 
of many genera of living mammals which are required for an exhaustive comparison 
of their fossil congeners. Finally, in the case of Siwalik fossils, there occurs the 
additional and special difficulty of taking up the work in the incomplete state it was 
left at the premature death of Dr. Falconer, and of determining ill-defined, imper- 
fectly described species in Calcutta, without access to the original specimens in 
London. This last difficulty has been the cause of several errors in the specific 
determinations which occiu’ in this volume. 
On the above grounds, I venture to hope that any want of references or com- 
j)arisons to European fossils, and consequent possible shortcomings in this work, 
will be looked upon with a lenient eye by my European and American fellow 
workers. 
In conclusion, it is but fair to mention that although there has devolved upon 
myself the task of describing the Siwalik fossils in the Indian Museuni of Calcutta, 
yet that the far more onerous task of amassing and bringing together that, perhaps, 
unrivalled series has devolved upon my colleagues in the Geological Survey, chief 
among whom are Messrs. W. T. Blanford, F. Fedden, W. Theobald, and A. B. 
Wynne. By far the largest share of this work has been executed through the 
indefatigable energy and perseverance of Mr. Theobald, who, through heat and 
cold, drought and rain, has traversed many a weary mile of the hills and plains of 
the Punjab to attain his object : to him especially are due the thanks of all 
interested in the history of the tertiary vertebrates of India. 
Indian Museum, 
Calcutta, January 1880. 
] 
R. LYDEKKER. 
1 I have the authority of the Superintendent of the Geological Survey of India to offer named duplicate 
specimens of described Siwalik fossils in exchange for named specimens of teeth of European or American tertiary . 
mammals. 
