From the Cabinet of Curiosities: Here is a special Victorian era specimen of Oncolpia (=Brachiolites) elegans. I acquired it from someone who had no idea what they had, for $10 mixed among some other non fossil items. In my opinion this fossil is priceless, it will never be sold or traded, instead it will eventually be donated to an appropriate permanent museum collection. It was originally collected by Joshua Toulmin Smith and was most likely prepared and subsequently labeled by Henry Alleyne Nicholson, who prepared over 4000 glass slides in his career. "Nicholson pioneered the use of thin sections in identifying and interpreting the internal structure of fossil invertebrates" (Long et al. 2003). A true gem of British Palaeontological history!
Long, S.L., Taylor, P.D., Baker, S., & Cooper, J. 2003
Some early collectors and collections of fossil sponges represented in the Natural History Museum, London.
The Geological Curator, 7:353-362 PDF LINK