C iv ] 
PART II 
X. On the Organization of the Fossil Plants of the Coal-Measures. — Part IX. By 
Professor W. C. Williamson, F.R.S. page 319 
XI. New Determination of the Mechanical Equivalent of Heat. By James Prescott 
Joule, D.C.L., LL.D., F.P.SS. L. and F., Ac., President of the Literary and 
Philosophical Society of Manchester .....365 
XII. On the Structure and Development of the Skull in the Common Snake (Tropido- 
notus natrix). By William Kitchen Parker, F.P.S 385 
XIII. Addition to Memoir on the Transformation of Elliptic Functions. By A. Cayley 
Sadlerian Professor of Mathematics in the University of Cambridge . . 419 
XIV. The Croonian Lecture. — On the Structure of the Stylcisteridce, a Family of 
the Hydroid Stony Cored s. By H. N. Moseley, F.R.S., Fellow of Exeter 
College, Oxford, late Naturalist on board H.M.S. ‘ Challenger’ . . . . 425 
XV. On the Development of the Parasitic Isopoda. By J. F. Bltllar, B.A., Trin. 
Coll., Cambridge. Communicated by Dr. Michael Foster, F.R.S., Prcelector 
of Physiology in Trinity College, Cambridge 505 
XVI. On the Placentation of the Apes, with a Comparison of the Structure of their 
Placenta with that of the Human Female. By Wm. Turner, M.B. ( Londfi 
F.R.SS . L. and E., Professor of Anatomy in the University of Edinburgh 523 
XVII. Observations on the Nervous System of Aurelia aurita. By Edward Albert 
Schafer, Assistant Professor of Physiology in University College, London . 
Communicated by W. Sharpey, M.D., LL.D., F.R.S. 563 
XVIII. On the Modifications of the Simple and Compound Eyes of Insects. By 
B. Thompson Lowne, F.R.C.S., Lecturer on Physiology at the Middlesex 
Hospital Medical School, Arris and Gale Lecturer on A natomy and Physiology 
in the Royal College of Surgeons, Ac. Communicated by Prof. W. II. Flower, 
F.R.S. ' 577 
XIX. A Tenth Memoir on Qualities. By A. Cayley, F.R.S., Sadlerian Professor 
of Pure Mathematics in the University of Cambridge 603 
XX. On the Classification of Loci. By W. K. Clifford, F.R.S., Professor of Applied 
Mathematics in University College, London 663 
XXI. On the Osteology of Polyodon folium. By Thomas William Bridge, B.A., 
Scholar of Trinity College, and Demonstrator of Comparative Anatomy in the 
University of Cambridge. Communicated by Alfred Newton, 31. A., F.R.S., 
Professor of Zoology and Comparative A natomy in the University of Cam- 
bridge 683 
