X 



Mr. Davidson prepared tlie article Brachiopoda for the " Encyclopedia 

 Britannica," and has monographed the entire series of Brachiopoda 

 collected during the exploration of H.M. ship " Challenger." 



Thirty years have passed since the publication of his general intro- 

 duction to the first volume of his extensive monographs, and well 

 may it be said that seldom has fortune more completely equipped a 

 student for his life-work than in the present case, in which more than 

 ordinary artistic talent, liberal education, and independent means 

 were joined to unsurpassed devotion in the pursuit of knowledge, 

 with just impartiality in the recognition of the labours of others in 

 the same field of research. Mr. Davidson was one of the most 

 unselfish of men, ready to aid all who worked and sought his advice 

 and opinion upon the intricacies of the intimate structure of the 

 Brachiopoda. Few more enthusiastic students ever enriched the 

 pages of scientific literature, or probably committed fewer errors in 

 the description and delineation of the voluminous mass of species 

 that enrich the 3000 pages and 250 plates left as a lasting memorial 

 of industry and learning. Unhappily Mr. Davidson has not lived to 

 see the proofs of his final monograph on the recent species of Bra- 

 chiopoda about to be issued by the Linnean Society.* 



Beyond the monographs in the pala3ontographical volumes, most of 

 Mr. Davidson's investigations have been published in the " Quarterly 

 Journal of the Geological Society," the "Bulletin de la Societe 

 Geologique de France," the "Annals and Magazine of Natural His- 

 tory," the "Geological Magazine," "Proceedings" of the Linnean 

 Society of Normandy and of the Zoological Society of London, 

 " Transactions " of the Geological Society of Glasgow and of the 

 Royal Society of Liege. 



In 1880 Mr. Davidson was deputed by the President and Council of 

 the Geological Society of London to represent the Society at the 

 celebration of the fiftieth Anniversary of the foundation of the French 

 Geological Society ; he was received in Paris with great distinction. 

 The Councils of the Royal Society of London, the Linnean Society, 

 the Zoological Society, the Royal Society of Edinburgh, the Geological 

 Society of Edinburgh, the Geological Society of Glasgow, the Royal 

 Academy of Ireland, the Royal Geological Society of Ireland, and 

 the Paleeontological Society of London all commissioned Mr. Davidson 



* Less than one-third of the known species (1000) of Brachiopoda were unknown 

 when Mr. Davidson published the introduction to his great work in 1850. To this 

 volume the late Dr. W. B. Carpenter appended an elaborate description of the 

 "Intimate Structure of the Shells of Brachiopoda," and Sir Richard Owen a learned 

 contribution on the "Anatomy of Terebratula." The number of British species, 

 which in 1850 comprised 13 genera and 450 species, have now expanded to 74 

 genera and 1000 species and varieties, these residts being almost entirely due to the 

 researches of Mr. Davidson. 



