LIST OF ILLUSTRATIONS, 
Plates 17 to 19. — General Sir Edward Sabine on Terrestrial Magnetism. 
Plate 20. — Messrs. Fleeming Jen kin and J. A. Ewing on Friction between Surfaces 
moving at Low Speeds. 
Plates 21 to 29. — Mr. W. K. Parker on the Structure and Development of the Skull 
in the Urodelous Amphibia. 
Plates BO and 31. — Mr. G. J. Romanes on the Locomotor System of Medusae. 
