Correspondence and research papers (unannotated reprints of scientific discussion papers have been removed to the library otherwise publication details have been noted and indexed).

People, places and research topics discussed:

• folder containing copy of JW Spengel 'Die Benennung der Enteropneusten-Gattungen' 1901
  
  
• pp 225-226 'Families and Genera of Enteropneusta"
  
  
• research notes "spengel 1901"