[ X ] 
XI. On Multiple Contact of Surfaces. By William Spottiswoode, M.A., 
Treas. B.S page 227 
X. On the Development of the Teeth of Fishes (Elasmobranchii and Teleostei). By 
Charles S. Tomes, M.A. Communicated by John Tomes, F.B.S. . . . 257 
XI. The Croonian Lecture. — Preliminary Observations on the Locomotor System of 
Medusae. By George J. Romanes, M.A., F.L.S., &c. Communicated by Professor 
Huxley, LL.D., Sec. B.S . , &c , . 269 
XII. On the Refraction of Sound by the Atmosphere.. By Professor Osborne Reynolds. 
Communicated by Professor Stokes, Sec. B.S. . 315 
