﻿112 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  

  

  curred; 
  6 
  species 
  of 
  Gasteropoda, 
  Chemnitzia 
  Jieddingtonensis 
  and 
  

   Gerithium 
  muricatum 
  being 
  amongst 
  the 
  number 
  ; 
  15 
  genera 
  and 
  

   21 
  species 
  of 
  Lamellibranchiata 
  ; 
  Gidaris 
  Jlorigemma, 
  the 
  only 
  

   species 
  illustrating 
  the 
  Echinoidea 
  ; 
  with 
  4 
  typical 
  Corals, 
  Tham- 
  

   nastrcea, 
  Isastrcea, 
  Monilivaltia, 
  and 
  .EhabdopJiyllia. 
  There 
  is 
  no 
  

   indication 
  of 
  the 
  Lower 
  Calcareous 
  Grit. 
  

  

  The 
  Yorkshire 
  Basin. 
  

   130 
  miles 
  north 
  of 
  Upware 
  the 
  Coral 
  Rag 
  of 
  Yorkshire 
  makes 
  its 
  

   southernmost 
  appearance. 
  

  

  The 
  authors 
  subdivide 
  the 
  Yorkshire 
  Corallian 
  area 
  into 
  four 
  

   districts 
  — 
  (1) 
  the 
  Scarborough, 
  (2) 
  the 
  Pickering, 
  (3) 
  the 
  Ham- 
  

   bleton, 
  and 
  (4) 
  the 
  Howardian 
  districts. 
  

  

  The 
  Scarborough 
  district 
  is 
  most 
  ably 
  described 
  by 
  the 
  authors, 
  

   both 
  in 
  this 
  communication 
  and 
  by 
  one 
  of 
  them 
  (Mr. 
  Hudleston) 
  

   in 
  a 
  iDaper 
  read 
  before 
  the 
  Geologists' 
  Association 
  (vol. 
  iv. 
  p. 
  353 
  

   et 
  seqq.). 
  The 
  fine 
  section 
  at 
  Filey, 
  a 
  little 
  to 
  the 
  north 
  of 
  the 
  

   Brig, 
  exposes 
  the 
  Upper 
  Calcareous 
  series 
  and 
  the 
  Eiley-Brig 
  

   Calc-grit, 
  the 
  Lower 
  Calcareous 
  series, 
  and 
  the 
  Lower 
  Calcareous 
  

   Grit 
  proper. 
  The 
  first 
  is 
  in 
  two 
  divisions, 
  and 
  about 
  13 
  feet 
  in 
  

   thickness 
  : 
  the 
  upper 
  (No. 
  1) 
  contains 
  few 
  fossils 
  ; 
  from 
  the 
  second 
  

   (No. 
  2) 
  23 
  species 
  were 
  obtained 
  — 
  

  

  Ammonites 
  4 
  species. 
  

  

  Gasteropoda 
  4 
  „ 
  

  

  Lamellibranchiata 
  .... 
  15 
  „ 
  

  

  23 
  

  

  The 
  Ammonites 
  are 
  all 
  characteristic, 
  A. 
  cordatus 
  and 
  A. 
  perarmatus 
  

   being 
  the 
  chief 
  forms 
  ; 
  they 
  arc 
  associated 
  with 
  Chemnitzia 
  hedding- 
  

   tonensis, 
  Littorina 
  muricata, 
  Gervillia 
  avicidoides 
  large 
  and 
  abundant, 
  

   and 
  Pholadomya 
  decemcostata. 
  The 
  Eiley-Brig 
  Calc-Grit 
  is 
  10 
  feet 
  

   thick, 
  and 
  composed 
  of 
  massive 
  yellow 
  calcareous 
  grit, 
  characterized 
  

   by 
  a 
  large 
  Ostrea, 
  var. 
  of 
  0. 
  bidlata. 
  

  

  The 
  Lower 
  Calcareous 
  series 
  is 
  divided 
  into 
  two 
  groups, 
  the 
  

   upper 
  15 
  feet, 
  the 
  lower 
  11 
  feet 
  thick. 
  25 
  species 
  occur 
  in 
  the 
  

   lower 
  group. 
  No 
  Gasteropoda 
  seem 
  to 
  occur 
  here 
  ; 
  but 
  there 
  are 
  

   10 
  Lamellibranchiata, 
  4 
  Brachiopoda 
  (the 
  characteristic 
  Rliyncho- 
  

   nella 
  Thurmanni 
  being 
  abundant, 
  and 
  6 
  species 
  of 
  other 
  groups, 
  

   with 
  Waldheimia 
  Hudlestoni 
  and 
  W. 
  buccidenta), 
  and 
  5 
  genera 
  and 
  

   5 
  species 
  of 
  Echinodermata. 
  

  

  The 
  Lower 
  Calcareous 
  Grit 
  proper 
  is 
  about 
  60 
  feet 
  in 
  thickness, 
  

   and 
  occupies 
  the 
  base 
  of 
  the 
  section. 
  The 
  soft 
  calcareous 
  sands 
  

   contain 
  huge 
  ball-stones 
  with 
  nests 
  of 
  fossils. 
  Trigonia 
  triquetra, 
  

   Pinna 
  lanceolata, 
  Ostrea 
  solitaria, 
  &c. 
  occur 
  in 
  the 
  upper 
  division. 
  

   The 
  lowest 
  part 
  of 
  this 
  Lower 
  Calc-grit 
  is 
  rich 
  in 
  fossils 
  — 
  Ammo- 
  

   nites 
  jperarmatus, 
  A. 
  cordatus, 
  Perna 
  quadrata, 
  and 
  Astrojpecten 
  

   rectus 
  ; 
  below 
  is 
  the 
  Oxford 
  Clay 
  (toe. 
  cit. 
  pp. 
  315-319). 
  

  

  The 
  authors 
  carefully 
  describe 
  the 
  Corallian 
  series 
  in 
  the 
  interior 
  

   of 
  the 
  country, 
  illustrating, 
  through 
  the 
  gorge 
  of 
  the 
  Derwent 
  at 
  the 
  

   Eorge 
  valley, 
  a 
  complete 
  section 
  of 
  the 
  whole 
  Corallian 
  series 
  from 
  

  

  