VI 
PREFACE. 
insuperable, owing to the increase of Zoological Literature, and 
especially to the extension of its publication in distant parts of 
the world. 
On the other hand, there can be no doubt that the attempt to 
make the annual volume include all the literature bearing the same 
date as itself, though, as we have seen, doomed to failure from the 
very commencement of the work, has been one of the chief causes 
of the delays that have occurred in the publication of several 
volumes ; the Recorders having been tempted to defer the pre- 
paration of their records by their knowledge that the delay would 
enable them to include some additional literature. 
It is intended in future to publish the volume in August or 
September, including in each special record all literature not pre- 
viously dealt with that may have reached the London libraries, or 
the Recorder, sufficiently early to be noticed by the latter. Should 
circumstances render it impossible to obtain a record of any of the 
subjects in good time, delay will be avoided by the publication of 
the volume without such record. Every effort will, however, be 
made to avert so undesirable a proceeding ; and in case of failure 
to do so it will be arranged that the record of the -following year 
shall atone for the deficiency of its predecessor. 
D. SHARP. 
Cambridge, Sept. 3 , 1892 . 
