﻿REV. 
  W. 
  DOWNES 
  ON 
  THE 
  BLACXDOWN 
  BEDS. 
  

  

  Disocheta 
  Meyeri 
  (J. 
  S. 
  Gardner). 
  G-eol. 
  Mag, 
  1880, 
  pi. 
  iii. 
  fig. 
  5. 
  

  

  Pyrgiscus 
  Woodwardii. 
  Geol. 
  Mag. 
  1876, 
  pi. 
  iii. 
  fig. 
  19. 
  K 
  

  

  Littorina 
  gracilis 
  (Sow.). 
  J, 
  B, 
  V. 
  Fitton, 
  pi. 
  xviii. 
  fig. 
  5. 
  

  

  conica 
  (Sow.). 
  B, 
  CE. 
  ? 
  Pbasianella. 
  

  

  monilifera 
  (Sow.). 
  J, 
  E, 
  V, 
  E, 
  CE. 
  

  

  rotundata 
  (Sow.). 
  B, 
  OE. 
  ? 
  Phasianella. 
  

  

  pungens 
  (Sow.). 
  J, 
  B, 
  W, 
  D, 
  CE. 
  Fitton, 
  pi. 
  xviii. 
  fig. 
  5. 
  ? 
  Pbasianella. 
  

  

  Phasianella 
  striata 
  (Sow.). 
  B, 
  "W, 
  D. 
  Fitton, 
  pi. 
  xviii. 
  fig. 
  15. 
  

  

  pusilla 
  (Sow.). 
  CE. 
  

  

  * 
  sp. 
  ? 
  J, 
  E. 
  

  

  formosa. 
  B. 
  Fitton, 
  pi. 
  xviii. 
  fig. 
  14. 
  

  

  Dentalium 
  cylindricurn 
  (Sow.). 
  J. 
  

   * 
  medium 
  (Sow.). 
  J, 
  B, 
  V, 
  CE. 
  

  

  Entalis 
  Meyeri 
  (J. 
  S. 
  Gardner). 
  Q. 
  J. 
  G. 
  S., 
  Feb. 
  1878, 
  pi. 
  iii. 
  fig. 
  40. 
  

  

  Pileopsis 
  Seeleyana 
  (J. 
  S. 
  Gardner). 
  Q. 
  J. 
  G. 
  S., 
  May 
  1877, 
  pi. 
  vii. 
  figs. 
  5-7. 
  

   #Actaeon 
  afiinis 
  (Sow.). 
  Common. 
  Beds 
  7-10.- 
  

  

  *Avellana 
  iucrassata 
  (Mant.) 
  = 
  ~RmgicxAsb 
  incrassata 
  (Sow.). 
  Common. 
  Beds 
  

   7-10. 
  

  

  Cephalopoda. 
  

  

  Nautilus. 
  2 
  species. 
  E, 
  V, 
  W, 
  T. 
  

   Ammonites 
  Beuclantii 
  (Brongn.). 
  J. 
  

  

  Goodhallii 
  (Sow.). 
  Common. 
  

  

  varicosus 
  (Sow.). 
  Common. 
  

  

  lautus 
  (Sow.). 
  E. 
  

  

  splendens 
  (Sow.). 
  B, 
  T, 
  V, 
  W, 
  D, 
  CE. 
  

  

  interruptus 
  (d'Orb.). 
  D. 
  

  

  serratus 
  (Park.). 
  E. 
  

  

  auritus 
  (Sow.). 
  B. 
  

  

  denarius 
  (Sow.). 
  B, 
  T, 
  V, 
  W. 
  

  

  tuberculatus 
  (Sow.). 
  B, 
  W, 
  E. 
  

  

  Toxoceras 
  Emericianus 
  (d'Orb. 
  ), 
  = 
  Hamites 
  spinulosus 
  (Sow.). 
  B, 
  V, 
  E. 
  

  

  The 
  Ammonites 
  at 
  Blackdown 
  seem 
  to 
  have 
  been 
  found 
  mostly 
  in 
  

   the 
  lower 
  concretionary 
  beds 
  ; 
  but 
  I 
  have 
  found 
  one 
  or 
  two 
  indivi- 
  

   duals 
  of 
  A. 
  varicosus 
  in 
  bed 
  10. 
  Mr. 
  Vicary 
  has 
  one 
  undeterminable 
  

   fragment 
  of 
  an 
  Ammonite 
  from 
  Haldon. 
  It 
  is 
  the 
  only 
  instance 
  

   of 
  an 
  Ammonite 
  or, 
  indeed, 
  of 
  any 
  Cephalopod 
  from 
  Haldon 
  that 
  I 
  

   can 
  hear 
  of. 
  

  

  An 
  analysis 
  of 
  the 
  above 
  list 
  teaches 
  us 
  that 
  the 
  Blackdown 
  fauna 
  

   (omitting 
  the 
  few 
  corals) 
  amounts 
  to 
  196 
  species, 
  and 
  that 
  50 
  of 
  these 
  

   occur 
  at 
  Haldon 
  also. 
  

  

  Of 
  these 
  50 
  fossils 
  in 
  common, 
  1 
  is 
  a 
  plant, 
  1 
  is 
  an 
  Annelid, 
  1 
  is 
  a 
  

   Brachiopod, 
  38 
  are 
  Lamellibranchiata, 
  8 
  are 
  Gasteropoda, 
  and 
  1 
  (a 
  

   single 
  individual) 
  is 
  a 
  Cephalopod. 
  

  

  We 
  find 
  also 
  that 
  in 
  every 
  instance 
  in 
  which 
  the 
  Haldon 
  fauna 
  

   agrees 
  with 
  that 
  oT 
  Blackdown, 
  bed 
  10 
  seems 
  to 
  be 
  the 
  probable 
  

   downward 
  limit. 
  It 
  is 
  significant 
  that 
  Siphonia 
  pyriformis, 
  Inoce- 
  

   ramus 
  sulcatus, 
  and 
  Trigonia 
  aliformis 
  are 
  all 
  apparently 
  absent 
  at 
  

   Haldon 
  ; 
  while 
  we 
  might 
  almost 
  say 
  the 
  same 
  thing 
  of 
  Pectunculus 
  

   umbonatus 
  and 
  of 
  Ammonites 
  generally 
  f 
  . 
  This 
  negative 
  evidence 
  is 
  

   further 
  confirmed 
  by 
  the 
  absence 
  of 
  concretions 
  suitable 
  for 
  making 
  

   whetstones. 
  

  

  Positive 
  evidence 
  points 
  in 
  the 
  same 
  direction 
  ; 
  Pecten 
  quadricos- 
  

  

  t 
  Mr. 
  Vicary 
  has 
  2 
  specimens 
  of 
  the 
  former 
  and 
  1 
  fragment 
  of 
  the 
  latter. 
  

  

  