Caption:
Diving beetle, Dytiscus dimidiatus 1, common whirligig beetle, Gyrinus natator 2, Cyclous vittatus 3, and great silver water beetle, Hydrophilus piceus 4.. Handcoloured steel engraving by William Lizars from James Duncans Natural History of Beetles, in Sir William Jardines Naturalists Library, W.H, Lizars, Edinburgh, 1835. James Duncan was a Scottish zoologist and entomologist 1804-1861.