LIST  OF  ILLUSTRATIONS. 
Plate  I. — Mr.  Gassiot  on  the  Stratifications  and  Dark  Band  in  Electrical  Discharges  as 
observed  in  Torricellian  Vacua. 
Plates  II.  III.  IV.  V. — Mr.  Hornee  on  the  Alluvial  Land  of  Egypt. 
Plates  VI.  VII.  VIII. — Dr.  T.  Williams’s  Eesearches  on  the  Structure  and  Homology 
of  the  Reproductive  Organs  of  the  Annehds. 
Plates  IX.  X.  XI. — Professor  Owen  on  the  Skull  and  Teeth  of  the  Placodus  laticeps. 
Plates  XII.  XIII.  XIV.  XV.  XVI.  XVII. — Mr.  J.  Lockhart  Clarke  on  the  Intimate 
Structure  of  the  Brain,  Human  and  Comparative. 
Plates  XVIII.  XIX.  XX.  XXI.  XXII.— Professor  Owen  on  the  Megatherium. 
Plates  XXIII.  XXIV.  XXV.  XXVI.— Dr.  J.  S.  Bowerbank  on  the  Anatomy  and 
Physiology  of  the  Spongiadse. 
Plate  XXVII. — Mr.  Ceace  Calvert  and  Mr.  R.  Johnson  on  the  Relative  Power  of 
Metals  and  Alloys  to  conduct  Heat. 
Plates  XXVHI.  XXIX. — Mr.  Fairbairn  on  the  Resistance  of  Tubes  to  collapse. 
Plates  XXX.  XXXI.  XXXII.  XXXIII.  XXXIV.  XXXV.  XXXVI.  XXXVII. 
XXXVIH.  XXXIX. — The  Admiralty  Astronomical  Experiment  on  the  Peak  of 
Teneriffe. 
Plates  XL.  XLI.  XLII.  XLIII.  XLIV.  XLV.  XLVI.— Mr.  C.  Spence  Bate  on  the 
Development  of  Decapod  Crustacea. 
Plates  XL VII.  XLVIII. — Mr.  J.  Lister  on  the  Cutaneous  Pigmentary  System  of  the 
Frog. 
Plates  XLIX.  L.  LI. — Sir  Charles  Lyell  on  the  Structure  of  Lavas  which  have  con- 
solidated on  steep  slopes. 
Plates  LII.  LIII.  LIV.  LV.  LVI.  LVII.  LVIII.  LIX.  LX.  LXI.  LXH.  LXIII. 
LXIV.  LXV.  LXVI. — Mr.  Hancock  on  the  Organization  of  the  Brachiopoda. 
Plates  LXVII.  LXVIII.  LXIX.  LXX.— Sir  P.  G.  Egerton  on  Chondrosteus,  an  Ex- 
tinct Genus  of  the  Sturionidae. 
Plate  LXXI. — Mr.  C.  De  Morgan  on  the  Structure  and  Functions  of  the  Hairs  of  the 
Crustacea. 
