Ulisse Aldrovandi (1522-1605), an Italian Naturalist, wrote his observations first on small slips of papers, which he later cut up and glued into a catalogue, very much like Conrad Gessner. Before doing this, he kept them in bags, one for each letter of the alphabet. Whether these bags were hung on hooks, as the previous post shows, I do not know. It is not unlikely, however.
On the other hand, he kept his specimens in pigeon holes (4500 in 66 armoires).
1. For Gessner, see here.