﻿300 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  

  

  constricted 
  behind 
  the 
  anterior 
  or 
  byssal 
  portion, 
  and 
  is 
  covered 
  by 
  

   lines 
  of 
  rugae 
  and 
  lines 
  of 
  growth. 
  

  

  y 
  9. 
  Orthonota 
  Gramhysioides, 
  sp. 
  nov. 
  PI. 
  XYI. 
  fig. 
  10. 
  

  

  (Compare 
  Cypricardia 
  Ludoviciana, 
  Rouault, 
  Bull. 
  Soc. 
  Geol. 
  Fr. 
  

   2nd 
  ser. 
  vol. 
  viii. 
  p. 
  374.) 
  

  

  Transverse 
  oblong, 
  rounded 
  at 
  both 
  ends, 
  with 
  prominent 
  curved 
  

   beaks 
  overhanging 
  the 
  thin 
  edentulous 
  hinge-line. 
  A 
  broad 
  de- 
  

   pression 
  runs 
  from 
  the 
  beak 
  to 
  the 
  front 
  margin, 
  making 
  the 
  shell 
  

   trilobed, 
  and 
  partially 
  obliterating 
  the 
  strong 
  concentric 
  rugae 
  which 
  

   ornament 
  the 
  whole 
  shell. 
  These 
  are 
  very 
  strong 
  rounded 
  ridges 
  

   on 
  the 
  convex 
  anterior 
  portion, 
  and 
  become 
  duplicated 
  and 
  inter- 
  

   lined 
  as 
  they 
  pass 
  over 
  the 
  abrupt 
  but 
  not 
  keeled 
  umbonal 
  ridge 
  

   behind. 
  

  

  The 
  ornaments 
  on 
  this 
  pretty 
  species 
  (which, 
  notwithstanding 
  

   some 
  discrepancies, 
  closely 
  resembles 
  Rouault's 
  shell 
  from 
  Gahard) 
  

   recal 
  those 
  of 
  Grammysia, 
  to 
  which 
  the 
  genus 
  Orihonota 
  is 
  closely 
  

   allied. 
  The 
  name 
  is 
  intended 
  to 
  express 
  this 
  affinity. 
  M. 
  de 
  Yer- 
  

   neuil 
  thinks 
  this, 
  too, 
  may 
  be 
  Devonian. 
  I 
  confess 
  I 
  do 
  not. 
  

  

  Cypricardia 
  Mariana, 
  Rouault, 
  appears 
  to 
  belong 
  to 
  the 
  same 
  

   group, 
  but 
  has 
  fine 
  concentric 
  ridges. 
  

  

  ys 
  10. 
  LrRODESMA 
  cjelata, 
  spec. 
  nov. 
  PI. 
  XYI. 
  fig. 
  7. 
  

  

  Ovate, 
  11 
  lines 
  long 
  by 
  half 
  an 
  inch 
  high 
  at 
  the 
  slightly 
  promi- 
  

   nent 
  beak, 
  which 
  is 
  placed 
  at 
  the 
  posterior 
  ? 
  * 
  fourth, 
  where 
  the 
  

   shell 
  is 
  widest. 
  In 
  advance 
  of 
  this 
  the 
  shell 
  tapers 
  rapidly, 
  and 
  the 
  

   anterior 
  ? 
  end 
  is 
  obtusely 
  pointed, 
  almost 
  almond-shaped. 
  

  

  The 
  surface 
  is 
  closely 
  covered 
  with 
  fine 
  lines 
  of 
  growth, 
  but 
  ap- 
  

   pears 
  smooth. 
  The 
  muscular 
  scars 
  are 
  deep, 
  divided 
  from 
  the 
  um- 
  

   bonal 
  cavity 
  by 
  thick 
  subcardinal 
  ridges. 
  The 
  hinge-plate 
  broad, 
  

   and 
  has 
  beneath 
  the 
  beak 
  six 
  or 
  seven 
  radiating 
  teeth, 
  of 
  which 
  the 
  

   posterior? 
  one 
  (that 
  nearest 
  the 
  rounded 
  end) 
  is 
  the 
  largest. 
  

  

  11. 
  Arca? 
  Naranjoana, 
  De 
  Yern. 
  ? 
  PI. 
  XYI. 
  fig. 
  8. 
  Bull. 
  Soc. 
  

   Geol. 
  Fr. 
  2nd 
  ser. 
  vol. 
  xii. 
  1855, 
  pi. 
  26. 
  fig. 
  12. 
  

  

  This 
  agrees 
  so 
  well 
  with 
  De 
  Yerneuil's 
  figure 
  and 
  description 
  

   (except 
  the 
  hinge-area, 
  which 
  we 
  cannot 
  see) 
  that 
  I 
  do 
  not 
  like 
  to 
  

   give 
  a 
  new 
  name. 
  It 
  is 
  a 
  little 
  shorter 
  in 
  proportion. 
  I 
  doubt 
  its 
  

   being 
  an 
  Area. 
  

  

  12. 
  Pal^arca 
  f 
  sectjnda, 
  spec. 
  nov. 
  PI. 
  XYI. 
  fig. 
  9. 
  

  

  Nearly 
  an 
  inch 
  wide, 
  three-quarters 
  high, 
  and, 
  with 
  valves 
  united, 
  

   4 
  lines 
  thick. 
  Subtrigonal-ovate, 
  the 
  beak 
  placed 
  at 
  the 
  anterior 
  ? 
  

   fourth, 
  pointed, 
  but 
  not 
  incurved. 
  Anterior 
  and 
  ventral 
  margins 
  

   well 
  rounded, 
  posterior 
  truncate. 
  Umbonal 
  ridge 
  angular, 
  arched, 
  

   leaving 
  but 
  a 
  narrow 
  vertical 
  anterior 
  slope. 
  Lunette 
  ? 
  Hinge- 
  

  

  * 
  I 
  am 
  not 
  sure 
  that 
  the 
  Lyrodesma 
  falls 
  into 
  the 
  usual 
  character 
  of 
  the 
  Nu- 
  

   cules 
  in 
  haying 
  the 
  beak 
  posterior. 
  

  

  f 
  For 
  the 
  characters 
  of 
  this 
  genus 
  see 
  Billings's 
  Reports 
  (under 
  Cyrtodonfa), 
  

   1857, 
  and 
  the 
  Memoirs 
  of 
  the 
  Geol. 
  Survey 
  Canada, 
  vol. 
  iii. 
  (ined.). 
  

  

  