Monograph of British Nudibranchiate Mollusca, by Joshua Alder and Albany Hancock, London, 1845

This pioneering work on nudibranchs is noteworthy for its many new species described and illustrated by Alder and Hancock and also as the first publication of The Ray Society, a scientific association still in existence.

George Johnston formed The Ray Society (named after John Ray, an eminent 17th English naturalist) in 1844 to publish affordable, accurate and well-illustrated scientific texts to accommodate and encourage the swelling interest in natural history. When Johnston's friend, Joshua Alder, an enthusiastic amateur marine biologist, showed him some of Albany Hancock's paintings of nudibranchs, Johnston was bowled over and determined to publish their work by paid subscription. The Blaschkas used later illustrations by Hancock for some of their nudibranch models.