﻿NIAGARA 
  FALLS 
  AND 
  VICINITY 
  I97 
  

  

  # 
  

  

  being 
  almost 
  flat. 
  Strong 
  sinus 
  and 
  fold 
  in 
  adult, 
  with 
  minor 
  plica- 
  

   tions 
  on 
  each; 
  strong 
  concentric 
  

   rugose 
  lamellae; 
  plications 
  less 
  

   rounded 
  than 
  preceding. 
  

  

  Found 
  in 
  the 
  Clinton 
  and 
  

  

  Rochester 
  beds 
  at 
  Niagara, 
  gen- 
  

  

  JIHU 
  

   erally 
  associated 
  with 
  the 
  preced- 
  

  

  ing 
  but 
  much 
  less 
  common. 
  Also 
  

  

  Fig. 
  114 
  Atrypa 
  rugosa 
  with 
  striae 
  enlarged 
  

  

  at 
  Lockport, 
  etc. 
  (Hall). 
  

  

  Genus 
  cyrtina 
  Davidson 
  

  

  [Ety,. 
  : 
  y.opzia^ 
  a 
  wicker 
  shield] 
  

  

  (1858. 
  British 
  Carbon. 
  Brachiopoda. 
  Monograph, 
  p. 
  66; 
  1893. 
  

   Pal. 
  N. 
  Y. 
  V. 
  8, 
  pt 
  2, 
  p. 
  43) 
  

  

  Shells 
  S 
  p 
  i 
  r 
  i 
  f 
  e 
  r 
  -like; 
  usually 
  small; 
  valves 
  very 
  unequal; 
  

   pedicle 
  valve 
  elevated, 
  with 
  a 
  high 
  cardinal 
  area, 
  the 
  delthyrium 
  of 
  

   which 
  is 
  covered 
  by 
  an 
  elongate, 
  convex 
  pseudodeltidium, 
  which 
  is 
  

   perforated 
  below 
  the 
  apex; 
  surface 
  plicate. 
  Dental 
  lamellae 
  strong, 
  

   converging 
  rapidly, 
  and 
  meeting 
  a 
  median 
  septum. 
  Cardinal 
  pro- 
  

   cess 
  a 
  double 
  apophysis. 
  Brachidium 
  an 
  extroverted 
  spire. 
  

  

  Cyrtina 
  pyramidalis 
  (Hall) 
  (Fig. 
  115). 
  

   Spirifer 
  pyramidalis 
  Hall 
  (1852. 
  

   Pal. 
  N. 
  Y. 
  2:266, 
  pi. 
  54) 
  

   H 
  Distinguishing 
  characters. 
  Pyramidal 
  

  

  .2k. 
  B^ 
  flat 
  brachial 
  valve; 
  extremely 
  convex 
  ped- 
  

  

  Fig. 
  115 
  Cyrtina 
  pyramidalis 
  with 
  iclc 
  valvc 
  ; 
  subaugular 
  pWcatious, 
  about 
  

  

  striae 
  enlarged 
  

  

  five 
  on 
  each 
  side 
  of 
  mesial 
  fold 
  and 
  sinus. 
  

   Found 
  " 
  near 
  the 
  top 
  and 
  just 
  below 
  the 
  edge 
  of 
  the 
  clifif 
  on 
  the 
  

   Niagara 
  river 
  above 
  Lewiston 
  " 
  (Hall). 
  

  

  Genus 
  spirifer 
  Sowerby 
  

  

  [Ety. 
  : 
  spira, 
  spire; 
  fero, 
  to 
  bear] 
  

  

  (1815. 
  Mineral 
  conchology, 
  2:42; 
  1894. 
  Hall 
  & 
  Clarke. 
  Pal. 
  

   N. 
  Y. 
  V. 
  8, 
  pt 
  2, 
  p. 
  i) 
  

  

  Shell 
  variously 
  shaped, 
  commonly 
  very 
  much 
  wider 
  than 
  long, 
  

   radially 
  plicated 
  or 
  striated, 
  crossed 
  by 
  concentric 
  growth 
  lines, 
  

   which 
  in 
  some 
  forms 
  are 
  lamellose 
  or 
  even 
  marked 
  by 
  spines. 
  

  

  ^ 
  

  

  form; 
  vertical 
  or 
  slightly 
  bent 
  area; 
  nearly 
  

  

  