Duncan (1937) provided detailed information that has been widely used to date names of new taxa described in early volumes of the Proceedings. The examinations reported here suggest that at least at the point where the year of publication is important Duncan was usually correct, and although exceptions are reported they are not of great consequence (although 14 of 42 volumes are anomalous). These exceptions relate to cases where the published pages differed from a multiple of the signature size by a couple of pages or so. Over the 41 volumes examined, two or more techniques were used to provide, economically, text needed to complete an article that would have over-run the number of signatures planned for the issue. The importance of retaining wrappers and binding them in is demonstrated by what can be learned from them.