﻿Ornithosaurian 
  Genus 
  Ornltlioclieirus. 
  555 
  

  

  the 
  premaxillse. 
  Group 
  A 
  certainly 
  approaclies 
  Ornitho- 
  

   desmus 
  latidens, 
  hnt 
  ditt'ers 
  considerably 
  iu 
  the 
  great 
  inflation 
  

   of 
  the 
  ventral 
  surface, 
  the 
  depth 
  of 
  the 
  preaxial 
  border, 
  the 
  

   lack 
  of 
  any 
  drawing 
  in 
  of 
  its 
  distal 
  termination 
  into 
  a 
  

   tubercle, 
  and 
  no 
  prolongation 
  of 
  the 
  dorsal 
  surface 
  of 
  the 
  

   bone 
  over 
  the 
  preaxial 
  border 
  as 
  a 
  wing. 
  Tlie 
  longitudinal 
  

   ridge 
  on 
  the 
  dorsal 
  surface 
  is 
  not 
  as 
  highly 
  developed. 
  The 
  

   ventral 
  surface 
  of 
  Oryiithodesmus 
  latidens 
  is 
  deeply 
  concave, 
  

   especially 
  towards 
  the 
  postaxial 
  border, 
  before 
  the 
  rise 
  of 
  the 
  

   bone 
  for 
  the 
  articular 
  facet, 
  where, 
  in 
  the 
  Cambridge 
  specimen, 
  

   tlui 
  convexity 
  is 
  the 
  greatest, 
  and 
  the 
  articular 
  facet 
  on 
  tiie 
  

   postaxial 
  side 
  is 
  more 
  oblique. 
  

  

  The 
  Carpal 
  s. 
  

  

  It 
  is 
  impossible 
  to 
  assign 
  any 
  of 
  these 
  bones 
  to 
  any 
  given 
  

   genus, 
  but 
  two 
  which 
  have 
  been 
  figured 
  by 
  Seeley 
  in 
  ' 
  Orni- 
  

   thosauria^ 
  are 
  sufficiently 
  close 
  to 
  Orniihodesmus 
  latidens 
  to 
  

   favour 
  an 
  assumption 
  that 
  they 
  belong 
  to 
  a 
  genus 
  with 
  the 
  

   humerus 
  of 
  the 
  type 
  of 
  Group 
  A. 
  These 
  bones 
  are 
  J. 
  b. 
  1, 
  

   no. 
  7, 
  pi. 
  V. 
  fig. 
  3, 
  a 
  proximal 
  belonging 
  to 
  the 
  right 
  carpus, 
  

   and 
  i. 
  b. 
  '6, 
  2i., 
  pi. 
  v. 
  fig. 
  7, 
  to 
  the 
  right 
  distal 
  carpal. 
  

  

  TJie 
  IVing 
  Metacarpal. 
  

  

  As 
  with 
  the 
  other 
  bones, 
  only 
  fragments 
  of 
  the 
  wing 
  

   metacarpal 
  occur, 
  and 
  therefore 
  comparisons 
  with 
  other 
  

   genera 
  from 
  the 
  length 
  cannot 
  be 
  made. 
  The 
  best-preserved 
  

   proximal 
  end 
  is 
  i. 
  b. 
  5, 
  3, 
  figured 
  by 
  Seeley 
  (pi. 
  vi. 
  figs. 
  2 
  

   & 
  3). 
  It 
  appears 
  to 
  belong 
  to 
  an 
  entirely 
  difierent 
  family 
  

   from 
  Ondthodesinus. 
  

  

  Several 
  specimens 
  possess 
  the 
  facet, 
  below 
  the 
  main 
  

   proximal 
  articulation, 
  for 
  the 
  bending 
  of 
  the 
  wing 
  ; 
  but 
  

   they 
  are 
  not 
  as 
  developed 
  or 
  directed 
  outwards 
  in 
  as 
  great 
  

   a 
  degree 
  as 
  in 
  Oruitkodcsnius 
  latidens. 
  

  

  The 
  Sternum. 
  

  

  The 
  anterior 
  projecting 
  process 
  is 
  the 
  only 
  part 
  of 
  the 
  

   sternum 
  preserved. 
  It 
  was 
  directed 
  well 
  forward, 
  down- 
  

   ward, 
  and 
  oblique 
  to 
  the 
  sternal 
  plate, 
  and 
  not 
  vertical 
  as 
  in 
  

   Ornithodesmus 
  latidens. 
  They 
  are 
  all 
  close 
  to 
  Ornithustuma 
  

   {Pteranodun) 
  and 
  Nyctosaurus, 
  but 
  they 
  cannot 
  be 
  appor- 
  

   tioned 
  either 
  to 
  the 
  dentigerous 
  or 
  edentulous 
  forms 
  of 
  the 
  

   Cauibridge 
  Greensand 
  for 
  certainty. 
  

  

  