﻿ANNIVERSARY 
  ADDRESS 
  OF 
  THE 
  PRESIDENT. 
  1 
  67 
  

  

  ontology 
  of 
  the 
  Junction-beds 
  of 
  the 
  Lower 
  and 
  Middle 
  Lias 
  in 
  Glou- 
  

   cestershire," 
  enumerates 
  12 
  genera 
  and 
  23 
  species 
  of 
  Gasteropoda 
  

   from 
  the 
  Jamesoni-beds, 
  20 
  species 
  of 
  Belemnites, 
  and 
  14 
  Ammonites 
  ; 
  

   indeed 
  from 
  this 
  one 
  zone 
  alone 
  he 
  catalogues 
  115 
  species 
  ; 
  and 
  from 
  

   the 
  same 
  beds 
  at 
  Radstock 
  12 
  genera 
  and 
  26 
  species 
  of 
  Gastero- 
  

   poda. 
  Neither 
  the 
  spinatus- 
  or 
  margaritatus-zones 
  at 
  Ramsay 
  and 
  

   Portree, 
  in 
  the 
  Isle 
  of 
  Skye, 
  although 
  rich 
  in 
  Conchifera, 
  have 
  yielded 
  

   any 
  Gasteropoda 
  ; 
  but 
  from 
  the 
  same 
  horizon 
  in 
  Yorkshire 
  24 
  species 
  

   have 
  been 
  collected. 
  The 
  higher 
  zones 
  of 
  Stephanoceras 
  annidatum, 
  

   Harpoceras 
  serpentinum, 
  H. 
  bifrons, 
  and 
  Lytoceras 
  jurense, 
  in 
  the 
  same 
  

   county, 
  yield 
  about 
  30 
  species. 
  The 
  remaining 
  Gasteropod 
  fauna 
  in 
  

   the 
  Upper 
  Lias 
  is 
  scattered 
  in 
  few 
  species 
  over 
  many 
  localities, 
  hardly 
  

   to 
  be 
  expressed 
  save 
  through 
  tabulation. 
  From 
  the 
  Middle 
  Lias 
  of 
  

   Dorsetshire, 
  through 
  the 
  researches 
  of 
  Mr. 
  Day, 
  40 
  species 
  have 
  

   been 
  recorded, 
  and 
  these 
  chiefly 
  from 
  the 
  Golden-Cap 
  and 
  Down- 
  

   Cliff 
  sections. 
  To 
  carry 
  the 
  analysis 
  to 
  individual 
  sections, 
  cliff 
  or 
  

   otherwise, 
  in 
  the 
  Liassic 
  rocks, 
  would 
  entail 
  endless 
  detail 
  ; 
  and 
  the 
  

   authors 
  named 
  have 
  exhaustively 
  worked 
  out 
  the 
  faunas 
  their 
  

   respective 
  papers 
  illustrate. 
  

  

  Cephalopoda. 
  — 
  Ammonitidce. 
  The 
  species 
  of 
  Ammonites 
  in 
  the 
  

   Lias 
  exceed 
  in 
  number 
  the 
  whole 
  of 
  the 
  species 
  in 
  the 
  other 
  divisions 
  

   of 
  the 
  Jurassic 
  rocks. 
  The 
  total 
  number 
  of 
  known 
  Jurassic 
  species, 
  

   including 
  the 
  Lias, 
  is 
  477. 
  The 
  number 
  known 
  in 
  the 
  three 
  divi- 
  

   sions 
  of 
  the 
  Lias 
  is 
  293. 
  

  

  173 
  occur 
  in 
  the 
  Lower 
  Lias, 
  

   54 
  ., 
  Middle 
  Lias, 
  

  

  79 
  „ 
  Upper 
  Lias 
  ; 
  

  

  and 
  only 
  3 
  species 
  pass 
  to 
  the 
  succeeding 
  Inferior 
  Oolite; 
  but 
  I 
  

   even 
  doubt 
  two 
  of 
  these. 
  

  

  Yery 
  few 
  species 
  are 
  common 
  to 
  all 
  three 
  divisions 
  of 
  the 
  Lias, 
  

   either 
  in 
  England 
  or 
  on 
  the 
  continent 
  of 
  Europe 
  ; 
  indeed 
  critical 
  

   study 
  demonstrates 
  that 
  few 
  or 
  none 
  pass 
  even 
  from 
  the 
  Lower 
  to 
  

   the 
  Middle, 
  or 
  from 
  the 
  Middle 
  to 
  the 
  Upper 
  Lias, 
  and 
  not 
  a 
  single 
  

   form 
  ranges 
  through 
  all 
  three 
  divisions 
  in 
  Britain. 
  The 
  only 
  6 
  

   species 
  common 
  to 
  the 
  Lower 
  and 
  Middle 
  Lias 
  are 
  JOJgoceras 
  defossum, 
  

   JE. 
  gagateum, 
  Amaltheus 
  Guibalianus, 
  A. 
  lenticularis, 
  JEgoctras 
  

   planicosta 
  ?, 
  Am. 
  Robinsoni. 
  The 
  only 
  3 
  species 
  common 
  to 
  the 
  

   Middle 
  and 
  Upper 
  Lias 
  are 
  Am. 
  calypso, 
  Lytoceras 
  cornucopias, 
  

   and 
  Lytoceras 
  fimbriatum. 
  Thus 
  only 
  9 
  species 
  out 
  of 
  293 
  bridge 
  

   over 
  the 
  two 
  divisions 
  of 
  Lower 
  and 
  Middle 
  and 
  Upper 
  and 
  

   Middle 
  Lias. 
  I 
  have 
  stated 
  that 
  only 
  3 
  species 
  of 
  Ammonites 
  

   connect 
  the 
  Upper 
  Lias 
  and 
  the 
  Inferior 
  Oolite. 
  Out 
  of 
  so 
  large 
  a 
  

   specific 
  fauna 
  in 
  one 
  genus, 
  and 
  that 
  a 
  pelagic 
  one, 
  this 
  is 
  a 
  

   remarkable 
  generalization, 
  and 
  is 
  not 
  only 
  given 
  on 
  my 
  own 
  autho- 
  

   rity, 
  but 
  through 
  the 
  direct 
  analysis 
  I 
  have 
  made 
  of 
  the 
  works 
  of 
  

   reliable 
  palaeontologists, 
  German, 
  French, 
  and 
  English. 
  I 
  stated 
  

   above 
  that 
  the 
  species 
  in 
  the 
  Lias 
  exceed 
  in 
  number 
  all 
  in 
  the 
  

   10 
  succeeding 
  horizons. 
  The 
  most 
  careful 
  research 
  shows 
  that 
  

  

  