Figure 4 from: Dickinson EC (2016) Reinforcing the foundations of ornithological nomenclature: Filling the gaps in Sherborn's and Richmond's historical legacy of bibliographic exploration. In: Michel E (Ed.) Anchoring Biodiversity Information: From Sherborn to the 21st century and beyond. ZooKeys 550: 107–134. https://doi.org/10.3897/zookeys.550.10170

Figure 4 - An example of two-state publication. Here the Proceedings of the Zoological Society of London, 1887, demonstrates a two-state situation. Left image: "first state". Right image: "second state". Images from Dickinson et al. (2011: 36) reproduced with permission from The Natural History Museum, London.