﻿KEV. 
  W. 
  DOWNES 
  ON 
  THE 
  BLACKDOWN" 
  BEDS. 
  81 
  

  

  used 
  sometimes 
  for 
  whetstones, 
  but 
  chiefly 
  for 
  building. 
  If 
  we 
  

   include 
  the 
  sand 
  layers 
  which 
  divide 
  the 
  concretionary 
  beds 
  with 
  the 
  

   concretions 
  themselves 
  we 
  may 
  estimate 
  it 
  at 
  about 
  4 
  feet. 
  There 
  

   are 
  but 
  few 
  fossils, 
  chiefly 
  Inoceramus 
  sulcatus 
  and 
  Trigonia 
  

   aliformis. 
  

  

  Bed 
  6, 
  = 
  bed 
  4 
  of 
  Fitton, 
  is 
  known 
  as 
  " 
  Gutters." 
  It 
  consists 
  of 
  

   sand 
  and 
  concretionary 
  layers, 
  is 
  about 
  5 
  feet 
  in 
  thickness, 
  and 
  

   contains 
  but 
  few 
  fossils, 
  but 
  among 
  them 
  Inoceramus 
  sulcatus 
  and 
  

   Pectunculus 
  umbonatus. 
  

  

  Bed 
  7. 
  A 
  very 
  fossiliferous 
  band 
  in 
  sand. 
  P. 
  umbonatus 
  is 
  the 
  

   prevailing 
  fossil 
  ; 
  but 
  there 
  are 
  many 
  others. 
  These 
  are 
  found, 
  to 
  

   use 
  the 
  expression 
  of 
  the 
  workmen, 
  in 
  " 
  clumps 
  ;" 
  that 
  is 
  to 
  say, 
  in 
  

   clusters 
  or 
  colonies, 
  with 
  valves 
  almost 
  always 
  attached, 
  and 
  with 
  

   species 
  but 
  little 
  mixed. 
  They 
  have 
  evidently 
  been 
  deposited 
  in 
  

   still 
  water, 
  and 
  are 
  apparently 
  in 
  the 
  habitat 
  in 
  which 
  they 
  lived 
  

   and 
  died. 
  Murex 
  calcar, 
  with 
  its 
  long 
  slender 
  spines, 
  is 
  often 
  found 
  

   perfect 
  at 
  this 
  zone. 
  

  

  Bed 
  8. 
  This 
  is 
  also 
  very 
  fossiliferous, 
  and 
  the 
  conditions 
  are 
  the 
  

   same 
  as 
  those 
  just 
  mentioned. 
  The 
  prevailing 
  fossil 
  is 
  Turritella 
  

   gramdata 
  in 
  " 
  clumps." 
  The 
  individuals 
  of 
  this 
  long 
  univalve 
  are 
  

   inclined 
  at 
  all 
  angles 
  toward 
  all 
  points 
  of 
  the 
  compass. 
  Sometimes 
  

   the 
  " 
  clumps 
  " 
  consist 
  wholly 
  or 
  mainly 
  of 
  Turritellce. 
  Sometimes 
  

   again, 
  they 
  are 
  mixed 
  with 
  Dimorphosoma 
  (Aporrhais) 
  calcarata 
  

   and 
  D. 
  neglecta 
  ; 
  Siphonia 
  pyriformis 
  seems 
  to 
  be 
  peculiar 
  to 
  this 
  bed. 
  

   This 
  and 
  the 
  preceding 
  bed 
  run 
  more 
  or 
  less 
  into 
  each 
  other, 
  but 
  the 
  

   order 
  is 
  generally 
  as 
  here 
  indicated. 
  Together 
  the 
  two 
  beds 
  con- 
  

   stitute 
  JBed 
  3 
  of 
  Fitton, 
  and 
  are 
  conjointly 
  about 
  4 
  feet 
  in 
  thickness. 
  

  

  Bed 
  9. 
  "Hard 
  fine 
  vein"=Fitton's 
  bed 
  2. 
  It 
  is 
  a 
  thin 
  layer 
  of 
  

   concretions 
  used 
  for 
  scythestones. 
  

  

  Bed 
  10. 
  " 
  Eed 
  rock"=Pitton's 
  bed 
  1. 
  It 
  is 
  a 
  very 
  fossiliferous 
  

   stratified 
  sandstone 
  in 
  layers 
  divided 
  by 
  sand 
  ; 
  Bivalves 
  in 
  this 
  bed 
  

   have 
  their 
  valves 
  nearly 
  always 
  separated, 
  and 
  species 
  are 
  completely 
  

   mixed. 
  There 
  is 
  some, 
  but 
  not 
  much, 
  indication 
  of 
  attrition, 
  and 
  

   some 
  of 
  the 
  fossils 
  are 
  broken, 
  while 
  all 
  lie 
  flatly 
  on 
  planes 
  of 
  bed- 
  

   ding. 
  The 
  sandstone 
  is 
  vertically 
  divided 
  at 
  intervals 
  of 
  1 
  to 
  3 
  feet 
  by 
  

   miniature 
  joints, 
  cutting 
  clean 
  through 
  hard 
  chalcedonic 
  fossils, 
  without 
  

   leaving, 
  as 
  a 
  rule, 
  a 
  single 
  projecting 
  splinter. 
  Some 
  of 
  the 
  fossils 
  

   have 
  their 
  surface 
  a 
  little 
  decomposed*, 
  thus 
  obliterating 
  the 
  finer 
  

   striae, 
  and 
  hence 
  perhaps 
  giving 
  origin 
  to 
  the 
  distinction 
  between 
  

   Cucullaza 
  fibrosa 
  and 
  G. 
  glabra, 
  both 
  of 
  which 
  occur 
  in 
  this 
  bed. 
  

   The 
  prevailing 
  fossil 
  is 
  Cyprina 
  cuneata. 
  Exogyra 
  conica 
  is 
  also 
  

   very 
  common. 
  Trigonia 
  scabricola, 
  though 
  not 
  so 
  common, 
  is 
  con- 
  

   fined 
  mainly, 
  if 
  not 
  entirely, 
  to 
  this 
  bed. 
  With 
  this 
  bed 
  or 
  some 
  

   part 
  of 
  it 
  the 
  Haldon 
  series 
  probably 
  begins, 
  while 
  with 
  the 
  bed 
  

   beneath 
  it 
  the 
  " 
  whetstone 
  beds 
  " 
  end. 
  Thickness 
  about 
  3 
  feet. 
  I 
  

   had 
  a 
  cartload 
  of 
  rock 
  from 
  this 
  bed 
  10 
  brought 
  to 
  my 
  house, 
  and 
  

   broke 
  it 
  up 
  at 
  leisure, 
  and 
  found 
  the 
  following 
  approximate 
  per- 
  

   centages 
  : 
  — 
  

  

  * 
  i. 
  e. 
  have 
  a 
  pulverulent 
  coating 
  in 
  the 
  rock, 
  which 
  rubs 
  off 
  with 
  a 
  touch. 
  

  

  Q.J.G.S. 
  No. 
  149. 
  g 
  

  

  