LIST OF ILLUSTRATIONS. 
Plates 19 to 25. — Professor W. C. Williamson on the Organization of the Fossil 
Plants of the Coal-Measures. 
Plate 26 . — Dr. J. P. Joule on a New Determination of the Mechanical Equivalent of 
Heat. 
Plates 27 to 33. — Mr. W. K. Parker on the Structure and Development of the Skull 
of the Common Snake ( Tropidonotus natrix). 
Plates 34 to 44. — Mr. H. N. Moseley on the Structure of the Stylasteridae, a Family 
of the Hydroid Stony Corals. 
Plates 45 to 47. — Mr. J. F. Bullar on the Development of the Parasitic Isopoda. 
Plates 48 and 49. — Professor W. Turner on the Placentation of the Apes, with a- 
Comparison of the Structure of their Placenta with that of the Human Female. 
Plates 50 and 51. — Professor E. A. Schafer on the Nervous System of Aurelia aurita. 
Plates 52 to 54. — Mr. B. T. Lowne on the Modifications of the Simple and Compound 
Eyes of Insects. 
Plates 55 to 57. — Mr. T. W. Bridge on the Osteology of Poly odon folium. 
Plates 58 to 65. — Mr. A. Sanders on the Anatomy of the Central Nervous System in 
Vertebrate Animals. 
Plates 66 to 70. — Dr. T. R. Robinson on the Determination of the Constants of the 
Cup Anemometer by Experiments with a Whirling Machine. 
