﻿1864.] 
  DAWKINS 
  — 
  HH^TIC 
  BEDS 
  AND 
  WHITE 
  LIAS. 
  397 
  

  

  Somerset, 
  taking, 
  in 
  the 
  course 
  of 
  my 
  examination, 
  upwards 
  of 
  seventy 
  

   sections. 
  The 
  results 
  of 
  this 
  exploration, 
  so 
  far 
  as 
  relates 
  to 
  the 
  

   Rhastic 
  beds 
  and 
  the 
  White 
  Lias, 
  are 
  embodied 
  in 
  the 
  following 
  paper. 
  

   The 
  suites 
  of 
  fossils 
  collected, 
  and 
  numbered 
  on 
  the 
  spot, 
  have 
  

   been 
  examined 
  by 
  my 
  friend 
  Mr. 
  Etheridge, 
  E.G.S., 
  without 
  whose 
  

   able 
  assistance 
  and 
  corrections 
  I 
  should 
  have 
  felt 
  diffident 
  in 
  my 
  own 
  

   determination 
  of 
  the 
  Invertebrata. 
  

  

  § 
  II. 
  Description 
  of 
  the 
  Sections. 
  

  

  1. 
  West 
  of 
  Watchet. 
  — 
  The 
  sea-shore 
  in 
  the 
  neighbourhood 
  of 
  

   Watchet, 
  in 
  West 
  Somerset, 
  affords 
  perhaps 
  one 
  of 
  the 
  very 
  best 
  

   sections 
  in 
  England 
  of 
  the 
  beds 
  between 
  the 
  Red 
  Marls 
  and 
  the 
  

   zone 
  of 
  Ammonites 
  BucMandi. 
  In 
  the 
  high 
  cliffs 
  the 
  relations 
  of 
  

   the 
  Gypsiferous 
  and 
  Red 
  and 
  Grey 
  Marls 
  are 
  clearly 
  shown. 
  Sea- 
  

   wards, 
  the 
  Rhsetic 
  beds, 
  and 
  the 
  limestones 
  of 
  the 
  zones 
  of 
  Am- 
  

   monites 
  planorbis 
  and 
  A. 
  BucMandi 
  — 
  here 
  forming 
  saddles, 
  or 
  

   with 
  but 
  gentle 
  dip, 
  there 
  vertical 
  and 
  standing 
  up 
  like 
  tombstones 
  

   — 
  afford 
  suites 
  of 
  fossils 
  remarkable 
  for 
  their 
  beauty 
  and 
  their 
  

   numbers. 
  Immediately 
  to 
  the 
  west 
  of 
  Watchet 
  Harbour, 
  the 
  

   Watchet 
  Eault 
  appears, 
  throwing 
  down 
  the 
  Lias 
  to 
  the 
  south, 
  and 
  

   causing 
  the 
  Ammonites 
  planorbis 
  shales, 
  having 
  a 
  dip 
  of 
  45° 
  N.N.E., 
  

   to 
  abut 
  against 
  the 
  Red 
  Marls, 
  which 
  dip 
  25° 
  S.S.W. 
  Thence 
  

   the 
  fault 
  runs 
  nearly 
  parallel 
  to 
  the 
  coast-line, 
  disappearing 
  in 
  the 
  

   sea 
  — 
  westward 
  at 
  Blue 
  Anchor, 
  eastward 
  in 
  the 
  Bay 
  of 
  Donni- 
  

   ford. 
  To 
  the 
  north 
  of 
  this, 
  and 
  near 
  low- 
  water 
  mark, 
  is 
  a 
  second, 
  

   running 
  parallel 
  to 
  the 
  first, 
  and 
  throwing 
  down 
  the 
  shales 
  with 
  

   A. 
  planorbis 
  to 
  the 
  north. 
  Between 
  these 
  two 
  faults 
  lie 
  the 
  

   sections 
  which 
  I 
  am 
  about 
  to 
  describe 
  — 
  the 
  one 
  to 
  the 
  west, 
  the 
  

   other 
  to 
  the 
  east 
  of 
  Watchet. 
  

  

  Immediately 
  to 
  the 
  south 
  of 
  the 
  Ammonites 
  planorbis 
  shales, 
  

   on 
  reaching 
  the 
  eastern 
  side 
  of 
  the 
  point 
  that 
  divides 
  the 
  small 
  

   Blue 
  Anchor 
  Bay 
  from 
  that 
  of 
  Watchet, 
  is 
  a 
  series 
  of 
  Red 
  and 
  Grey 
  

   Marls, 
  with 
  a 
  dip 
  of 
  13° 
  to 
  the 
  north, 
  increasing 
  westwards 
  to 
  30°. 
  

   The 
  lowest 
  of 
  these, 
  at 
  the 
  base 
  of 
  the 
  cliff, 
  is 
  a 
  soft 
  slate-coloured 
  

   marl 
  (A), 
  passing 
  into 
  black 
  at 
  the 
  bottom 
  : 
  4 
  feet. 
  Above 
  this 
  are 
  

   some 
  dark-grey 
  and 
  black 
  slaty 
  beds 
  (B), 
  with 
  layers 
  of 
  black 
  shale, 
  

   and 
  highly 
  charged 
  with 
  flesh-coloured 
  gypsum, 
  besides 
  contain- 
  

   ing 
  a 
  little 
  of 
  the 
  white 
  fibrous 
  variety 
  : 
  4 
  feet. 
  Then 
  occurs 
  a 
  dark 
  

   slate- 
  coloured 
  homogeneous 
  marlstone 
  (C), 
  4 
  feet 
  thick, 
  with 
  a 
  little 
  

   flesh-coloured 
  gypsum. 
  The 
  latter 
  is 
  deposited 
  in 
  the 
  fissures, 
  and, 
  

   from 
  their 
  obliquity 
  in 
  some 
  places, 
  it 
  gives 
  the 
  appearance 
  of 
  

   " 
  false 
  bedding." 
  It 
  occurs 
  also 
  in 
  the 
  true 
  bedding. 
  Above 
  this 
  

   is 
  a 
  coal-black 
  shale 
  (D), 
  presenting 
  a 
  marked 
  feature 
  in 
  the 
  section, 
  

   and 
  containing 
  gypsum 
  : 
  10 
  feet. 
  This 
  is 
  overlain 
  by 
  gypseous 
  grey 
  

   sandy 
  marls 
  (E), 
  much 
  indurated 
  : 
  10 
  feet. 
  Up 
  to 
  this 
  point 
  I 
  was 
  

   unable 
  to 
  detect 
  the 
  least 
  fragment 
  of 
  any 
  organism. 
  In 
  the 
  grey, 
  

   ripple-marked, 
  fissile, 
  sandy 
  marlstones, 
  6 
  feet 
  in 
  thickness 
  (F), 
  

   immediately 
  above, 
  organic 
  remains 
  were 
  very 
  abundant. 
  The 
  Anne- 
  

   lida 
  are 
  represented 
  by 
  very 
  numerous 
  holes 
  and 
  tracks 
  ; 
  of 
  the 
  Mol- 
  

   lusca, 
  the 
  Bivalves 
  by 
  Modiola 
  minima, 
  Pecten 
  Valoniensis, 
  Myacites 
  

  

  VOL. 
  XX. 
  PART 
  I. 
  2 
  F 
  

  

  