IN the current number of the Proceedings of the Zoological Society, comprising Parts 1 and 2 of Volume 114, the division into two series (A and B) has been discontinued. Accordingly, all papers will now be published in a single annual volume, containing four parts. The issue of the Proceedings in three series, (A) General and Experimental, (B) Systematic and Morphological, and (C) Abstracts of papers communicated at the scientific meetings, was introduced in 1937, and at the same time the practice of giving a serial number to each volume. Previously the volumes were referred to only by the year of issue, which occasionally introduced some uncertainty about the date of publication, since the last part of the volume for any particular year might not appear until January or February in the following year. A further complication arises as a result of the large number of pages contained in the Proceedings of some particular years, which necessitated their being bound in two volumes, and title pages and contents sheets were supplied for this purpose. It thus became necessary to refer to the first or second 'volume' of each year of issue. The use of a serial volume number, which will be printed on all future parts, will obviate this necessity, and simplify bibliographic references to publications in the Proceedings.