﻿ANNIVERSARY 
  ADDRESS 
  OF 
  THE 
  PRESIDENT. 
  1 
  73 
  

  

  opened 
  up 
  and 
  worked 
  for 
  " 
  Cement," 
  the 
  Upper 
  at 
  Whitby 
  for 
  jet 
  

   and 
  alum-shale 
  ; 
  and 
  the 
  working 
  of 
  these 
  three 
  products 
  has 
  un- 
  

   doubtedly 
  led 
  to 
  the 
  making 
  of 
  large 
  collections 
  from 
  the 
  two 
  areas. 
  

   Yet, 
  largely 
  as 
  these 
  lower 
  beds 
  are 
  worked 
  at 
  Barrow 
  on 
  Soar, 
  

   only 
  6 
  genera 
  and 
  7 
  species 
  have 
  hitherto 
  occurred 
  there. 
  But 
  it 
  

   must 
  be 
  remembered 
  that 
  it 
  is 
  only 
  the 
  very 
  lowest 
  beds 
  that 
  are 
  

   worked 
  at 
  Barrow, 
  and 
  that 
  only 
  a 
  limited 
  vertical 
  section 
  is 
  exhibited. 
  

   The 
  genera 
  and 
  species 
  occurring 
  there 
  are 
  Cosmolepis 
  Egertoni,Dape- 
  

   dius 
  orbis, 
  Lepidotus 
  serratus, 
  Pholidophorus 
  Hastingsice, 
  P. 
  StricJc- 
  

   landi, 
  Pycnodus 
  liassiciis, 
  and 
  Ptycholepis 
  minor. 
  Small 
  as 
  is 
  this 
  

   assemblage, 
  it 
  is 
  the 
  largest 
  known 
  out 
  of 
  the 
  Lyme-Regis 
  area. 
  Thus 
  

   the 
  106 
  Lower-Lias 
  species 
  are 
  nearly 
  all 
  from 
  the 
  cliff-sections 
  and 
  

   foreshore 
  at 
  Lyme 
  Regis. 
  

  

  The 
  genera 
  most 
  largely 
  represented 
  are 
  the 
  following 
  : 
  — 
  

  

  * 
  iEchmodus 
  . 
  . 
  . 
  . 
  

  

  11 
  species 
  

  

  all 
  Lower 
  Lias. 
  

  

  *Dapedius 
  . 
  . 
  . 
  

  

  8 
  

  

  55 
  

  

  55 
  55 
  

  

  55 
  

  

  Eugnathus 
  . 
  . 
  . 
  

  

  12 
  

  

  55 
  

  

  11 
  5, 
  

  

  „ 
  1 
  Middle, 
  1 
  Upper 
  Lias. 
  

  

  Hybodus 
  

  

  10 
  

  

  55 
  

  

  all 
  „ 
  

  

  55 
  

  

  Leptolepis 
  . 
  . 
  . 
  

  

  6 
  

  

  55 
  

  

  3 
  „ 
  

  

  „ 
  4 
  Upper 
  Lias. 
  

  

  Pachycormus 
  . 
  

  

  11 
  

  

  55 
  

  

  4 
  „ 
  

  

  „ 
  8 
  in 
  Upper. 
  

  

  Pholidophorus. 
  

  

  . 
  10 
  

  

  55 
  

  

  all 
  „ 
  

  

  55 
  

  

  The 
  remaining 
  36 
  genera 
  contain 
  only 
  one 
  or 
  a 
  few 
  species 
  each 
  ; 
  

   23 
  are 
  represented 
  only 
  by 
  single 
  species. 
  

  

  Very 
  few 
  Lower-Lias 
  species 
  range 
  into 
  the 
  Middle 
  or 
  Upper 
  Lias. 
  

   Eugnathus 
  chirotes 
  is 
  the 
  only 
  form 
  out 
  of 
  the 
  106 
  that 
  is 
  common 
  

   to 
  both 
  Middle 
  and 
  Lower 
  Lias, 
  and 
  Leptolepis 
  Bronni 
  and 
  Pachy- 
  

   cormus 
  leptosteus 
  are 
  the 
  only 
  two 
  species 
  common 
  to 
  the 
  Lower 
  and 
  

   Upper 
  Lias. 
  No 
  single 
  form 
  occurs 
  in 
  all 
  three 
  divisions. 
  The 
  18 
  

   species 
  of 
  Upper-Lias 
  fish 
  illustrate 
  6 
  genera, 
  Eugnathus 
  1 
  species, 
  

   Lepidotus 
  3, 
  Leptolepis 
  4, 
  Macrosemius 
  1, 
  Pachycormus 
  8, 
  and 
  Pty- 
  

   cholepis 
  1 
  species. 
  This 
  almost 
  total 
  dying-out 
  of 
  the 
  Lower-Lias 
  

   species, 
  without 
  any 
  known 
  or 
  visible 
  unconformity 
  between 
  that 
  

   division 
  and 
  the 
  succeeding 
  Middle 
  and 
  Upper 
  Lias, 
  has 
  yet 
  to 
  

   be 
  accounted 
  for. 
  A 
  zoological 
  group 
  so 
  prolific 
  in 
  individuals 
  as 
  

   the 
  Fishes, 
  and 
  pelagic 
  in 
  habit, 
  must 
  have 
  constituted 
  an 
  important 
  

   element 
  in 
  the 
  long- 
  continued 
  history 
  of 
  the 
  Lower-Lias 
  deposits. 
  

   The 
  36 
  genera 
  with 
  only 
  a 
  few 
  known 
  species 
  each, 
  and 
  the 
  23 
  with 
  

   only 
  one 
  and 
  few 
  individuals, 
  conclusively 
  show 
  that 
  when 
  we 
  have 
  

   more 
  exhaustively 
  examined 
  the 
  Lias 
  in 
  its 
  strike 
  through 
  Eng- 
  

   land, 
  these 
  rarer 
  genera 
  will 
  receive 
  large 
  specific 
  additions. 
  Our 
  

   table 
  shows 
  at 
  a 
  glance 
  the 
  almost 
  complete 
  specific 
  break 
  between 
  

   the 
  Lower 
  and 
  Middle 
  Lias, 
  and 
  the 
  total 
  change 
  that 
  took 
  place 
  at 
  

   the 
  close 
  of 
  the 
  formation. 
  The 
  only 
  4 
  known 
  Inferior-Oolite 
  forms 
  

   are 
  Strophodus 
  magnus, 
  S. 
  subreticulatus, 
  S. 
  tenuis, 
  and 
  Hybodus 
  

   crassus, 
  the 
  last 
  genus 
  only 
  being 
  represented 
  in 
  the 
  Lias. 
  The 
  

   58 
  Great-Oolite 
  species 
  stand 
  alone 
  also. 
  

  

  * 
  Mchmodus 
  and 
  Dapedius 
  are 
  probably 
  one 
  genus. 
  

  

  