First published in 1928, this bibliography lists approximately 3,800 titles on the subject of sponges, spanning the period 1551-1913. Gualtherus Vosmaer was a prolific thinker in this field, and this book is the product of 29 years of intensive research. This near-exhaustive bibliography places little-known works alongside more established papers, a range which made it, on its publication, unique. As such, it is a brilliant resource for discovering lesser-known texts on this extensive subject, and a fascinating compilation of historical writing on Porifera, both living and fossilised. As its editor Bidder remarks, 'the biology of 100 years ago affords most delightful and charming reading' and here, in one volume, is a list of papers and books which afford exactly this pleasure. Vosmaer's bibliography gives the reader the opportunity to explore both past theories and discoveries, and to understand the scientific study of these fascinating sea creatures in its historical context.