V 
EXPLANATORY. 
This Volume is printed in the Divisions enumerated on p. vi. 
The pagination of each Division is separate, and is given at the 
left-hand top corner of the pages. The number and name of the 
Division is given as a heading on each left-hand page. The Registra- 
tion Numbers are given at the right-hand top corner of the right- 
hand pages. The date 1915 corresponding to the bulk of the 
literature indexed is given at the right-hand top corner of the left- 
hand page. 
In the Subject Index of each Division authors are quoted by name 
only. The full references will be found in the Title Section of the 
Division. 
The Literature indexed is mainly that of 1915 but includes entries 
for earlier years that have been received too late for inclusion in 
previous volumes. 
On account of the present international situation, the Royal 
Society of London found itself unable to undertake at present any 
financial responsibility for any volumes of the International Catalogue 
subsequent to those of the Fourteenth Annual Issue. 
Under these circumstances the Zoological Society of London 
arranged to undertake the issue of the present volume, which is the 
fifty-second of the Zoological Record, and would have been N. Zoology 
of the Fifteenth Annual Issue of the International Catalogue. Its 
preparation has been conducted as closely as possible on the model of 
the previous volumes prepared jointly by the International Catalogue 
and the Zoological Society. 
It can now be purchased from the Zoological Society of London 
n,t the price of £2, either in the binding of the Zoological Record or 
in series with the International Catalogue. 
Volume 53, dealing with the Literature of 1916, is in preparation. 
