[ Vi ] 
XX. Additional Observations on the Diffusion of Liquids. {Third Memoir.) By 
Thomas Graham, Esq., F.R.S., F.C.S. 8$c pag® 483 
XXI. The Figure and Primitive Formation of the Earth, or Researches in Terrestrial 
Physics . — Part I. By Henry FIennessy, M.R.I.A. 8^c. Communicated by 
Major Ludlow Beamish, F.R.S 495 
XXI L Researches in Terrestrial Physics . — Part II. .Si/ H enry Hennessy, 71/./?./.^. 
^c. Communicated by 31ajor laUDhOW Bf.amish, F.R.S. 511 
XXin. On the Rolling Motion of a Cylinder. By the Rev. Henry Moseley, M.A., 
F.R.S. , Corresponding Member of the Institute of France 549 
XXIV. Observations upon the Anatomy and Physiology of Salpa and Pyrosoma. By 
Thomas Henry Huxley, Assistant-Surgeon R.N. {late of H.M.S. ‘‘ Rat tie - 
snake' j. Communicated by Prof. Edward Forbes, F.R.S 567 
XXV. Remarks upon Appendicularia and Doliolum, two genera of the Tunicata. By 
Thomas Henry Huxley, Assistant- Surgeon R.N. {late of H.M.S. “ Rattle- 
snake"). Communicated by Prof. Edward Forbes, F.R.S. 595 
XXVI. Researches into the Structure of the Spinal Chord. By ii. Lockhart Clarke, 
Esq. Communicated by Samuel Solly, Esq., F.R.S 60/ 
XXVII. On the Meteorology of the Lake District of Cumberland and IVestmoreland, 
including the Results of Experiments on the Fall of Rain at various heights, up 
to 3166 feet above the sea-level. — Fourth paper, for the year 1850. By John 
Fletcher Miller, F.R.S., F.R.A.S., A.ssoc. Inst. C.E. Sfc 623 
XXV ill. On the Annual V ariation of the Magnetic Declination, at different periods of 
the Day. By Lieut. -Col. Edward Sabine, R.A., VP. and Treas. of the Royal 
Society 635 
XXIX. Investigations into the Structure and Development of the Scales and Bones of 
Fishes. By W. C. Williamson, Esq., Professor of Natural History, Anatomy 
and Physiology, in Owens College, Manchester. Communicated by Edwin Lan- 
KESTER, M.D., F.R.S 643 
XXX. Report of f urther Observations upon the Tidal Streams of the North Sea and 
