Pocket file containing miscellaneous letters to GPB on science and from scientists; typescript, proofs and photographs for "The form of a sponge in relation to its currents" 1922 3 (envelope and 2 files); notes on flagella 1924 5, and typescript: "Theory of the sponge flagellum", apparently for BAAS Southampton 1925; notes and proof of "The skeleton and classification of calcareous sponges" 1898 (envelope); folder containing letter of J. Stanley Gardiner 13 Sep 1922, sending something, and a printed article on sponges by F. Dujardin, from 'Annales des Sciences Naturelles', Paris 1838