IV 
CONTENTS. 
On a Pre-Brachial Stage in the Development of Gomatula, and its 
importance in relation to certain Aberrant Forms of Extinct 
Crinoids. By Professor Allman, . . . .91 
Letter from Sir D. Brewster relative to the specimens of Topaz 
with Pressure Cavities presented by him to the Museum of the 
Society, . . . . . , .95 
On the Polarisation of Rough Surfaces, and of Substances that 
reflect White or Coloured Light from their Interior. By Sir 
David Brewster, K.H., F.R.S., . . . .96 
On a Clay Deposit with Fossil Arctic Shells, recently observed in 
the Basin of the Forth. By the Rev. Thomas Brown, F.R.S E., 96 
On the Remarkable Occurrence of Graphite in Siberia. By 
Thomas C. Archer, Esq., . . . . .97 
On the Polarisation of the Atmosphere. By Sir David Brewster, 
K.H., F.R.S., . . . . . .100 
Concluding Note on the Star Observations at Elchies. By Pro- 
fessor C. Piazzi ^myth, ..... 100 
On a new Fossil Opliiuridan, from Post-pliocene strata of the Valley 
of the Forth. By Professor Allman, . . . .101 
Accompanjflng Note to Portions of Lead from the Roof of the 
Lower Storey of Nelson’s Monument, injured by Lightning on 
the evening of 4th February 1863. By Professor C. Piazzi Smyth, 105 
Note on the Anatomical Type in the Funis Umbilicalis and 
Placenta. By Professor Simpson, . . . .112 
On Earth-Currents during Magnetic Calms, and their Connection 
with Magnetic Changes. By Balfour Stewart, Esq., M.A., 
F.R.S. Communicated by Professor Tait, . . .112 
Note on a Pictish Inscription in the Churchyard of St Vigeans. 
By Professor Simpson, . . . ^ . .113 
On some Kinematical and Dynamical Theorems. By Professor 
W. Thomson, . . . . . .113 
Note on a Quaternion Transformation. By Professor Tait, . 115 
On the Conservation of Energy, By Professor Tait, . . 121 
On Fagnani’s Theorem. By H. F. Talbot, LL.D., . . 126 
On the Theory of Parallel Lines. By H. F. Talbot, LL.D., . 126 
Address to His Royal Highness the Prince of Wales, . .126 
Opening Address, Session 1863-64. By Professor Innes, one of 
the Vice-Presidents, ...... 130 
On the Morphological Relationships of the Molluscoida and Coelen- 
terata and of their leading members, inter se. By John Denis 
Macdonald, R.N., F.R.S,, Surgeon of H.M.S. “Icarus.” Com- 
municated by Professor Maclagan, .... 155 
On the External Anatomy of a new Mediterranean Pteropod. By 
John Denis Macdonald, R.N. Communicated by Professor 
Maclagan, . . . . . . ‘ . 155 
On the Limits of our Knowledge respecting the Theory of Parallels. 
By Professor Kelland, . . . . . .155 
On the great Drift-Beds with Shells in the South-west of Arran. 
By the Rev. Robert Boog Watson, B.A , F.R S.E., Hon. Mem. 
Naturw. Ver. Liineburg, . . . . .157 
