xxvi CONTENTS. 



PAGE 



XXXI. Description of Calamoichthys, a new Genus of Ganoid Fish from 

 Old Calabar, Western Africa, forming an addition to the 

 Family Polypterini. By John Alexander Smith, M.D., 

 F.R.C.P.E.,F.R.S.E. (With two Plates, XXXI., XXXII.), 457 



XXXII. Note on Formulae representing the Fecundity and Fertility of 



Women. By Professor Tait, ..... 481 



PART III. (1866-07.) 



XXXIII. On the Colours of the Soap-Bubble. By Sir David Brewster, 



K.H., F.R.S. (With a Plate, XXXIII.), . . .491 



XXXIV. On the Figures of Equilibrium in Liquid Films. By Sir David 



Brewster, K.H., F.R.S. (With three Plates XXXIV.- 

 XXXVI. i, .505 



XXXV. On the Third Co-ordinate Branch of the Higher Calculus. By 



Edward Sang, Esq., . . . . .515 



XXXVI. On Functions with Recurring Derivatives. By Edward Sang, 



Esq., ....... 523 



XXXVII. On the Application of the Principle of Relative, or Proportional, 

 Equality to International Organisation. By Professor 

 Lorimer, . . . . . . .557 



XXXVIII. Some Mathematical Researches. By H. Fox Talbot, Esq., . 573 



XXXIX. On Centres, Faisceaux, and Envelopes of Homology. By Rev. Hugh 

 Martin, M.A., Member of the Mathematical Society of 

 London, and Examiner in Mathematics in the University 

 of Edinburgh. Communicated by Professor Kelland, . 591 



XL. On the Arctic Shell- Clay of E lie and Errol, vieived in connection 

 with our other Glacial and more recent Deposits. By the Rev. 

 Thomas Brown, F.R.S. E. (With a Plate, XXXVIL), . 617 



XLI. Description of a Double Holophote Apparatus for Lighthouses, and 

 of a Method of Introducing the Electric or other Lights. By 

 Sir David Brewster, K.H., D.C.L., F.R.S. (With a 

 Plate, XXXVIII.), 633 



