﻿Ornithosaurian 
  Genus 
  Oniitliocheiriis. 
  547 
  

  

  B, 
  C 
  will 
  be 
  found 
  to 
  belong 
  to 
  the 
  distal 
  ends 
  of 
  Groups 
  A, 
  

   33, 
  C 
  as 
  now 
  classified. 
  That 
  Group 
  A 
  belongs 
  to 
  a 
  genus 
  

   of 
  the 
  family 
  Ornithodesniidae 
  appears 
  to 
  be 
  certain 
  by 
  a 
  

   comparison 
  with 
  the 
  hnmerns 
  of 
  Ornithodesmus 
  latidens, 
  and. 
  

   from 
  Prof. 
  Williston^s^ 
  description 
  of 
  the 
  distal 
  end 
  of 
  

   the 
  humerus 
  of 
  OrnWiostoma 
  (Pteranodon) 
  yve 
  consider 
  the 
  

   distal 
  ends 
  of 
  Group 
  B 
  to 
  belong 
  to 
  that 
  genus, 
  and 
  there- 
  

   fore 
  to 
  the 
  edentulous 
  forms 
  of 
  the 
  Cambridge 
  Greensand. 
  

   Whether 
  the 
  jjroximal 
  ends 
  of 
  this 
  group 
  are 
  rightly 
  appor- 
  

   tioned 
  is 
  a 
  more 
  difficult 
  matter 
  to 
  determine, 
  for 
  the 
  base 
  

   is 
  all 
  that 
  remains 
  of 
  the 
  deltoid 
  crest, 
  the 
  most 
  characteristic 
  

   feature. 
  On 
  examination 
  of 
  these 
  specimens 
  it 
  appears 
  that 
  

   it 
  was 
  oblique 
  to 
  the 
  long 
  axis 
  of 
  the 
  condyle, 
  which, 
  as 
  far 
  as 
  

   it 
  goes, 
  agrees 
  with 
  Prof. 
  Williston's 
  f 
  descri|)tion 
  of 
  the 
  crest 
  

   in 
  Ormthostoma 
  {Pteranodoii). 
  "This 
  process, 
  the 
  radial 
  or 
  

   deltoid, 
  has 
  its 
  convex 
  rounded 
  extremity 
  directed 
  obliquely 
  

   forward 
  and 
  upward 
  and 
  outward/^ 
  yet 
  at 
  the 
  same 
  time 
  it 
  

   resembles, 
  perliaps 
  in 
  a 
  greater 
  degree, 
  his 
  account 
  of 
  Nycto- 
  

   snuriis 
  X, 
  " 
  the 
  deltoid, 
  radial, 
  or 
  lateral 
  process 
  very 
  large. 
  '^ 
  

   ''It 
  is 
  directed 
  forward 
  and 
  a 
  little 
  downward.^^ 
  He 
  also 
  

   says, 
  '' 
  The 
  ulnar 
  or 
  median 
  process 
  is 
  very 
  stout." 
  This, 
  

   together 
  with 
  the 
  fact 
  that 
  the 
  crest 
  is 
  more 
  distal 
  to 
  the 
  

   condyle 
  in 
  Nyctosaums, 
  seems 
  to 
  favour 
  a 
  gieater 
  affinity 
  to 
  

   Nyctosauriis 
  than 
  to 
  the 
  proximal 
  ends 
  in 
  Group 
  B 
  (? 
  Orni- 
  

   thostoma). 
  Thus, 
  he 
  remarks 
  §, 
  " 
  This 
  crest 
  is 
  further 
  

   removed 
  from 
  the 
  head 
  of 
  the 
  bone 
  than 
  is 
  the 
  case 
  in 
  species 
  

   of 
  Pteranodon.''^ 
  Perhaps 
  with 
  the 
  details 
  now 
  given 
  for 
  

   this 
  group 
  an 
  examination 
  of 
  the 
  American 
  specimens 
  would 
  

   enable 
  a 
  decision. 
  At 
  any 
  rate, 
  they 
  do 
  not 
  belong 
  to 
  

   Groups 
  A 
  or 
  C, 
  and 
  thus 
  in 
  all 
  probability 
  pertain 
  to 
  the 
  

   edentulous 
  forms. 
  In 
  regard 
  to 
  Group 
  C, 
  typified 
  by 
  the 
  

   perfect 
  humerus 
  J. 
  a. 
  6, 
  30, 
  there 
  is 
  not 
  even 
  a 
  suggestion 
  

   to 
  be 
  obtained 
  from 
  known 
  facts 
  as 
  to 
  which, 
  if 
  any, 
  of 
  the 
  

   remaining 
  genera, 
  formed 
  on 
  the 
  evidence 
  of 
  the 
  premaxillse, 
  

   it 
  belongs. 
  

  

  Radius 
  and 
  Ulna. 
  

   The 
  specimens 
  on 
  tablet 
  J. 
  a. 
  9 
  are 
  the 
  proximal 
  ends 
  of 
  

  

  * 
  S. 
  W. 
  Williston, 
  " 
  Restoration 
  of 
  Oi'vitkustoma" 
  Kansas 
  Univ. 
  

   Quart. 
  1897, 
  p. 
  45. 
  

  

  t 
  S. 
  W. 
  Williston, 
  ibid. 
  p. 
  44. 
  

  

  X 
  Id. 
  Field 
  Co]. 
  Mug. 
  Pub. 
  78, 
  g-eo. 
  ser. 
  vol. 
  ii. 
  no. 
  3, 
  p. 
  141. 
  

  

  § 
  Id. 
  Kansas 
  Univ. 
  Quart, 
  vol. 
  i. 
  18U2-8, 
  p. 
  6. 
  

  

  37* 
  

  

  