LIST OF ILLUSTRATIONS. 
Plates I. to VIII. — Mr. W. K. Parker on the Structure and Development of the Skull 
in the Salmon. 
Plates IX. and X. — Mr. Robert Mallet on Volcanic Energy. 
Plates XI. to XIII. — Mr. J. Norman Lockyer on Spectrum- Analysis in connexion 
with the Spectrum of the Sun. 
Plates XIV. to XVII. — Mr. W. Crookes on the Atomic Weight of Thallium. 
Plate XVIII. — The Astronomer Royal — Magnetical Observations in the Britannia 
and Conway Tubular Iron Bridges. 
Plates XIX. to XXI. — The Rev. Stephen J. Perry — Magnetic Survey of Belgium 
in 1871. 
Plates XXII. to XXXI. — Professor W. C. Williamson on the Organization of the 
Fossil Plants of the' Coal-measures. 
Plate XXXII. — Mr. Dugald MTvichan — Determination of the Number of Electro- 
static Units in the Electromagnetic Unit. 
Plate XXXIII. — Mr. E. A. Schafer on the Minute Structure of the Leg-muscles of the 
Water-beetle. 
Plate XXXIV. — Mr. E. Chambers on the Diurnal Variations of the Wind and Barometric 
Pressure at Bombay. 
Plates XXXV. to XL. — Dr. W. Kowalevsky on the Osteology of the Hyopotamidce. 
Plates XLI. to XLVII. — Report on the Exploration of Brixham Cave. 
Plate XLVIII. — The Earl of Rosse on the Radiation of Heat from the Moon. 
Plates XLIX. & L. — Dr. Rudolph yon Willemoes-Suhm on a new Genus of Amphipod 
Crustaceans. 
Plates LI. & LII. — Mr. «T. Norman Lockyer on Spectrum- Analysis in connexion with 
the Spectrum of the Sun. 
