The Hymenoptera Aculeata of the British Islands : a descriptive account of the families, genera, and species indigenous to Great Britain and Ireland, with notes as to habits, localities, habitats etc.
Edward Saunders 1896
This book is a classic work on aculeates and contains the only comprehensive work on British solitary bees (Apidae) yet published. It contains many hand coloured plates. The Biodiversity Heritage Library has made this book available to view or download for free online either as a pdf or higher quality jpeg images (large 100mb files):
Copies of the original book are worth several hundred pounds in price so this is a valuable addition to the digital library!