﻿ANNIVERSARY 
  ADDRESS 
  OF 
  THE 
  PRESIDENT. 
  1 
  93 
  

  

  Acrosalenia 
  6 
  species. 
  

  

  Cidaris 
  3 
  „ 
  

  

  Hemipedina 
  1 
  „ 
  

  

  Hemicidaris 
  8 
  „ 
  

  

  Pedina 
  2 
  „ 
  

  

  Pseudodiadema 
  .... 
  5 
  „ 
  

  

  Bhabdo 
  cidaris 
  1 
  „ 
  

  

  Stomechinus 
  1 
  „ 
  

  

  27 
  „ 
  

  

  13 
  genera 
  of 
  the 
  Echinoidea 
  Endocyclica 
  range 
  through 
  the 
  Jurassic 
  

   rocks, 
  and 
  they 
  are 
  represented 
  by 
  93 
  species 
  ; 
  very 
  few 
  have 
  long 
  

   ranges 
  in 
  time. 
  In 
  the 
  group 
  under 
  consideration 
  the 
  genera 
  Acro- 
  

   salenia, 
  Pedina, 
  and 
  Polycyphus 
  possess 
  species 
  of 
  long 
  duration 
  : 
  they 
  

   are 
  Acrosalenia 
  hemicidaroides, 
  A. 
  spinosa 
  (both 
  of 
  which 
  range 
  

   through 
  the 
  Lower 
  Oolites 
  to 
  the 
  Cornbrash), 
  Pedina 
  rotata 
  and 
  P. 
  

   SmitJiii, 
  Polycyphus 
  Normanus 
  ; 
  Hemicidaris 
  Bravenderi 
  and 
  Pseudo- 
  

   diadema 
  homostigma 
  pass 
  also 
  to 
  the 
  Cornbrash. 
  Thus 
  of 
  the 
  27 
  

   species, 
  7 
  pass 
  to 
  the 
  horizon 
  named. 
  

  

  Exocyclica. 
  — 
  5 
  genera 
  and 
  8 
  species 
  in 
  this 
  singular 
  group 
  of 
  the 
  

  

  Echinoidea 
  occur 
  in 
  the 
  Great 
  Oolite 
  ; 
  but 
  the 
  entire 
  Jurassic 
  rocks 
  

  

  have 
  yielded 
  8 
  genera 
  and 
  40 
  species. 
  The 
  Great-Oolite 
  genera 
  

  

  are 
  : 
  — 
  ™ 
  o 
  

  

  Clypeus 
  2 
  species. 
  

  

  Echinobrissus 
  3 
  „ 
  

  

  Galeropygus 
  1 
  „ 
  

  

  Pygaster 
  1 
  „ 
  

  

  Pygurus 
  1 
  „ 
  

  

  8 
  „ 
  

  

  Of 
  the 
  3 
  genera 
  and 
  32 
  species 
  beyond 
  those 
  above 
  named 
  none 
  

   occur 
  in 
  the 
  Great 
  Oolite 
  ; 
  they 
  chiefly 
  belong 
  to 
  the 
  Inferior 
  Oolite 
  ; 
  

   but 
  Clypeus 
  Mulleri 
  and 
  G. 
  Plottii 
  also 
  occur 
  in 
  the 
  Eorest 
  Marble, 
  

   and 
  Echinobrissus 
  orbicularis 
  passes 
  to 
  the 
  Cornbrash 
  and 
  Coral 
  Rag. 
  

   Asteroidea. 
  — 
  Only 
  2 
  genera 
  (Astropecten 
  with 
  3 
  species 
  and 
  Goni- 
  

   aster 
  with 
  1) 
  have 
  as 
  yet 
  been 
  detected 
  in 
  the 
  Great 
  Oolite 
  ; 
  but 
  

   11 
  genera 
  and 
  32 
  species 
  are 
  known 
  in 
  the 
  Jurassic 
  rocks. 
  They 
  

  

  Astropecten 
  14 
  species. 
  

  

  Goniaster 
  3 
  „ 
  

  

  Luidia 
  1 
  „ 
  

  

  Ophioderma 
  5 
  „ 
  

  

  Ophiolepis 
  2 
  „ 
  

  

  Ophiurella 
  1 
  „ 
  

  

  Plumaster 
  1 
  „ 
  

  

  Solaster 
  1 
  „ 
  

  

  Stellaster 
  1 
  „ 
  

  

  Tropidaster 
  1 
  „ 
  

  

  Uraster 
  2 
  

  

  32 
  

  

  5) 
  

  

  55 
  

  

  None 
  of 
  the 
  above 
  32 
  species 
  pass 
  to 
  higher 
  beds. 
  

  

  vol. 
  xxxviii. 
  p 
  

  

  