﻿I50 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  

  

  Crinoidea, 
  so 
  abundant 
  in 
  the 
  Carboniferous 
  seas, 
  are 
  represented 
  in 
  

   the 
  Lias 
  by 
  Eliabdocrinus, 
  Extracrinus, 
  and 
  Pentacrinus, 
  the 
  older 
  

   Palaeozoic 
  forms 
  disappearing 
  in 
  the 
  Permian 
  rocks. 
  No 
  form 
  of 
  

   irregular 
  Echinoidea 
  {Echinoidea 
  exocyclica) 
  has 
  yet 
  been 
  detected 
  

   in 
  either 
  of 
  the 
  three 
  divisions 
  of 
  the 
  Lias. 
  They 
  first 
  appear 
  in 
  

   the 
  lowest 
  bed 
  of 
  the 
  Inferior 
  Oolite, 
  and 
  are 
  there 
  individually 
  

   very 
  abundant. 
  

  

  Lower 
  Lias. 
  — 
  The 
  lowest 
  beds 
  of 
  the 
  Lias 
  (the 
  zone 
  of 
  JEgoceras 
  

   planorbis) 
  yield 
  at 
  Lyme 
  Eegis 
  and 
  other 
  localities 
  Cidaris 
  Edivardsii. 
  

   Pseudodiadema 
  lobatum, 
  Hemipedina 
  BeclieL 
  H. 
  JBoiverbanJcii, 
  and 
  

   H. 
  Tomesii. 
  

  

  The 
  zone 
  of 
  JEgoceras 
  angidatum 
  has 
  also 
  yielded 
  Cidaris 
  Edwardsii 
  

   and 
  Hemipedina 
  Tomesii, 
  together 
  with 
  Pentacrinus 
  psilonoti 
  and 
  

   P. 
  basaltiformis. 
  In 
  Yorkshire, 
  Dorsetshire, 
  and 
  Warwickshire 
  this 
  

   zone 
  yields 
  a 
  remarkable 
  and 
  prolific 
  fauna, 
  especially 
  of 
  Gasteropoda 
  

   and 
  Lamellibranchiata. 
  Messrs. 
  Tate 
  and 
  Blake, 
  in 
  their 
  'Yorkshire 
  

   Lias,' 
  exhaustively 
  detail 
  the 
  history 
  of 
  this 
  zone 
  in 
  Yorkshire. 
  Prof. 
  

   Tate, 
  in 
  1867 
  (Q. 
  J. 
  Gcol. 
  Soc. 
  vol. 
  xxiii.), 
  described 
  the 
  Lower 
  Lias 
  

   of 
  the 
  north-east 
  of 
  Ireland, 
  both 
  the 
  zone 
  of 
  JEgoceras 
  planorbis 
  

   and 
  that 
  of 
  Belemnites 
  acutus, 
  and 
  also 
  the 
  fossilifcrous 
  zone 
  of 
  jE. 
  an- 
  

   gidatum. 
  From 
  eight 
  localities 
  he 
  gives 
  a 
  list 
  of 
  102 
  species. 
  The 
  

   researches 
  of 
  Jules 
  Martin 
  in 
  the 
  Angulatum-beds 
  of 
  the 
  Cote 
  d'Or, 
  

   and 
  those 
  of 
  MM. 
  Terquem 
  and 
  Piette, 
  in 
  the 
  " 
  Lias 
  Infcrieur 
  do 
  

   l'est 
  de 
  la 
  France'' 
  (Mem. 
  de 
  la 
  Soc. 
  Geolog. 
  de 
  Prance, 
  2 
  ser. 
  

   tome 
  viii. 
  p. 
  1), 
  have 
  greatly 
  advanced 
  our 
  critical 
  knowledge 
  of 
  

   these 
  lower 
  divisions 
  of 
  the 
  Lias 
  of 
  France, 
  and 
  thrown 
  much 
  

   light 
  upon 
  the 
  history 
  of 
  the 
  English 
  deposits 
  of 
  the 
  same 
  age. 
  

   In 
  Yorkshire 
  alone 
  nearly 
  120 
  species 
  occur 
  in 
  this 
  zone, 
  50 
  of 
  

   which 
  are 
  Lamcllibranchs 
  and 
  27 
  Gasteropods, 
  with 
  5 
  species 
  of 
  

   Ammonites, 
  A. 
  Conybeari 
  and 
  A. 
  Joluistoni 
  being 
  amongst 
  them. 
  

   Some 
  species 
  pass 
  to 
  the 
  succeeding 
  Bucklandi-beds, 
  but 
  not 
  sufficient 
  

   to 
  allow 
  of 
  any 
  union 
  of 
  the 
  two 
  zones. 
  No 
  species 
  in 
  any 
  

   genera 
  occurring 
  in 
  the 
  Lias 
  pass 
  to 
  the 
  Inferior 
  Oolite 
  or 
  higher 
  

   beds. 
  In 
  the 
  Bucklandi-series 
  no 
  new 
  forms 
  have 
  been 
  detected, 
  

   either 
  in 
  France 
  or 
  England. 
  One 
  only, 
  Acrosalenia 
  rninuta, 
  is 
  

   added 
  to 
  the 
  fauna 
  of 
  the 
  Oxynotus-series. 
  The 
  same 
  species, 
  

   with 
  Pentacrinus 
  scalaris 
  and 
  P. 
  psilonoti, 
  pass 
  to 
  the 
  zone 
  of 
  

   Arietites 
  raricostatus. 
  

  

  Middle 
  Lias. 
  — 
  The 
  rich 
  and 
  prolific 
  horizon 
  of 
  JEyoceras 
  Jamesoni 
  

   includes 
  Opliioderma 
  Gaveyi, 
  Pentacrinus 
  Milleri, 
  Pseudodiadema 
  (?), 
  

   Plumaster 
  opliiuroides, 
  Extracrinus 
  subanyularis, 
  Millericrinus 
  Haus- 
  

   manni, 
  Pentacrinus 
  punctifer, 
  P. 
  robustus, 
  and 
  P. 
  laivis. 
  

  

  Both 
  in 
  the 
  north 
  and 
  south 
  of 
  England 
  the 
  Capricornus-clays 
  

   and 
  limestones, 
  which 
  succeed 
  everywhere 
  the 
  Jamesoni-series, 
  ex- 
  

   hibit 
  new 
  forms 
  of 
  the 
  Echinodermata, 
  chiefly 
  the 
  Asteriadse. 
  They 
  

   are 
  Ur 
  aster 
  carinatus, 
  Tropidaster 
  pectinatus, 
  Luiclia 
  Murchisoni, 
  

   Plumaster 
  ophiuroides, 
  Astropecten 
  Hastingsice, 
  Ophioderma 
  Milleri, 
  

   0. 
  Gaveyi,0. 
  carinatum, 
  Ophiolepis 
  Murrayi, 
  O.columba, 
  and 
  Penta- 
  

   crinus 
  interbrachiatus. 
  These 
  are 
  chiefly 
  northern 
  species 
  charac- 
  

   terizing 
  the 
  Middle 
  Lias 
  of 
  Yorkshire 
  at 
  Staithes, 
  Boulby, 
  Pobin 
  

   Hood's 
  Bay 
  (N. 
  Cheek), 
  Huntcliffe, 
  &c. 
  

  

  