﻿208 
  

  

  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Genus 
  liopteria 
  Hall 
  

  

  [Ety. 
  : 
  XsJo?, 
  smooth; 
  Tzrepov, 
  wing] 
  

  

  (1883. 
  Pal. 
  N. 
  Y. 
  V. 
  5, 
  pt 
  I, 
  p. 
  4) 
  

  

  Shell 
  aviculoid, 
  oblique, 
  subrhomboidal 
  ; 
  anterior 
  end 
  not 
  auricu- 
  

   late; 
  wing 
  large, 
  extremity 
  produced. 
  Hinge 
  narrow, 
  furnished 
  

  

  with 
  a 
  slender 
  lateral 
  tooth 
  just 
  pos- 
  

   terior 
  to 
  the 
  beak 
  and 
  nearly 
  parallel 
  

   to 
  the 
  hinge 
  line. 
  Ligament 
  external; 
  

   ligamental 
  area 
  narrow, 
  extending 
  

   the 
  entire 
  length 
  of 
  the 
  hinge, 
  marked 
  

   by 
  fine, 
  sharp, 
  longitudinal 
  striae. 
  Test 
  

   with 
  concentric 
  striae 
  but 
  without 
  rays. 
  

  

  Liopteria 
  (?) 
  subplana 
  (Hall) 
  (Fig. 
  

   136). 
  Avicula 
  subplana 
  Hall 
  

   (1852. 
  Pal. 
  N. 
  Y. 
  2:283, 
  Pl- 
  59) 
  

  

  Distinguishing 
  characters. 
  Depressed 
  

   convex 
  surface; 
  similarity 
  of 
  right 
  and 
  

   left 
  valves; 
  ill 
  defined 
  wing 
  and 
  ear; 
  

   concentric 
  striae; 
  absence 
  of 
  radii. 
  

   Found 
  in 
  the 
  Rochester 
  shale 
  at 
  

   Lockport 
  associated 
  with 
  Pterinea 
  emacerata, 
  etc. 
  (Hall). 
  

   Probably 
  also 
  at 
  Niagara. 
  The 
  generic 
  reference 
  is 
  provisional. 
  

  

  Genus 
  lyriopecten 
  Hall 
  

  

  [¥.ty. 
  : 
  Xuptov, 
  small 
  lyre; 
  pecten, 
  comb, 
  i. 
  e. 
  the 
  genus 
  Pec- 
  

   ten] 
  

  

  (1884. 
  Pal. 
  N. 
  Y. 
  V. 
  5, 
  pt 
  I, 
  p. 
  12) 
  

  

  Shell 
  inequivalve, 
  with 
  a 
  short 
  hinge 
  line 
  and 
  very 
  small 
  anterior 
  

   ear. 
  Cartilage 
  in 
  shallow 
  furrows^ 
  parallel 
  to 
  the 
  hinge 
  margin. 
  

   Surface 
  ornamented 
  with 
  rays. 
  

  

  Lyriopecten 
  orbiculoides 
  (nom. 
  nov.) 
  cf. 
  Avicula 
  (?) 
  or- 
  

   b 
  i 
  c 
  u 
  1 
  a 
  t 
  a 
  Hall 
  (1852. 
  Pal. 
  N. 
  Y, 
  2 
  1284, 
  pi. 
  59) 
  

  

  Distinguishing 
  characters. 
  Right 
  (?) 
  valve 
  convex; 
  left 
  (?) 
  valve 
  

   flat; 
  form 
  suborbicular, 
  hinge 
  line 
  short, 
  straight; 
  strong 
  radiating 
  

   striae 
  cancelated 
  by 
  equally 
  strong 
  concentric 
  striae, 
  forming 
  sur- 
  

   face 
  similar 
  to 
  Pterinea 
  emacerata. 
  

  

  Fig. 
  136 
  Liopteria 
  (?) 
  subplana 
  

  

  