﻿H. 
  G. 
  SEELEy 
  ON 
  NEUSTICOSATJRITS 
  PTTSLLLTJS. 
  357 
  

  

  Ophidians 
  ; 
  but 
  there 
  is 
  no 
  reason 
  to 
  regard 
  it 
  as 
  an 
  evidence 
  of 
  

   affinity. 
  Similarly 
  the 
  long 
  neck 
  recalls 
  the 
  lizard 
  from 
  the 
  Chalk 
  

   named 
  Dolichosaurus, 
  which 
  also 
  has 
  the 
  arches 
  joined 
  by 
  zygo- 
  

   sphene 
  and 
  zygantrum. 
  And 
  in 
  the 
  rib 
  rising 
  directly 
  from 
  the 
  

   side 
  of 
  the 
  vertebra 
  in 
  our 
  fossil, 
  without 
  transverse 
  processes 
  to 
  

   support 
  it, 
  the 
  character 
  is 
  more 
  Lacertian 
  than 
  in 
  Plesiosaurus. 
  

   But 
  it 
  should 
  also 
  be 
  remembered, 
  that 
  Pliosaurus, 
  and 
  Rhomaleo- 
  

   saurus 
  from 
  the 
  Lias, 
  like 
  Nothosaurus, 
  have 
  the 
  cervical 
  ribs 
  

   articulated 
  by 
  doable 
  heads, 
  as 
  in 
  Crocodiles 
  ; 
  so 
  that 
  much 
  weight 
  

   cannot 
  be 
  attached 
  to 
  characters 
  in 
  which 
  the 
  vertebral 
  column 
  

   shows 
  Lacertilian 
  analogies. 
  

  

  The 
  Pectoral 
  Arch 
  

  

  is 
  imperfectly 
  preserved 
  (PL 
  XIII. 
  fig. 
  1). 
  The 
  coracoid 
  on 
  the 
  left 
  

   side 
  is 
  entirely 
  removed 
  ; 
  on 
  the 
  right 
  side 
  it 
  is 
  complete. 
  It 
  has 
  

   very 
  much 
  the 
  form 
  of 
  an 
  ischium 
  of 
  Plesiosaurus, 
  and 
  is 
  as 
  unlike 
  

   the 
  coracoid 
  of 
  Plesiosaurs 
  as 
  could 
  be 
  while 
  still 
  formed 
  on 
  the 
  

   same 
  plan. 
  The 
  bones 
  were 
  directed 
  backward, 
  and 
  met 
  in 
  the 
  

   median 
  line 
  by 
  a 
  suture 
  which 
  was 
  not 
  more 
  than 
  7 
  mm. 
  long. 
  The 
  

   oblique 
  position 
  of 
  the 
  coracoid 
  will 
  be 
  best 
  understood 
  by 
  stating 
  

   that 
  the 
  median 
  suture 
  is 
  entirely 
  posterior 
  to 
  the 
  glenoid 
  cavity 
  for 
  

   the 
  humerus. 
  The 
  transverse 
  width 
  of 
  the 
  bone 
  is 
  about 
  12 
  mm. 
  

   Its 
  extreme 
  length, 
  measured 
  obliquely, 
  is 
  about 
  14 
  mm. 
  It 
  is 
  con- 
  

   stricted 
  in 
  the 
  middle 
  ; 
  but 
  the 
  anterior 
  concavity 
  is 
  shorter 
  and 
  deeper 
  

   than 
  the 
  posterior 
  concavity. 
  The 
  width 
  at 
  the 
  scapular 
  end 
  is 
  less 
  

   than 
  7 
  mm., 
  and 
  the 
  corresponding 
  antero-posterior 
  measurement 
  at 
  

   the 
  median 
  suture 
  is 
  more 
  than 
  8 
  mm. 
  At 
  the 
  suture 
  with 
  the 
  other 
  

   coracoid 
  there 
  is 
  a 
  small 
  wedge-shaped 
  interval 
  at 
  the 
  posterior 
  

   margin, 
  such 
  as 
  is 
  usually 
  seen 
  in 
  Plesiosaurs. 
  The 
  scapular 
  end 
  

   has 
  a 
  small 
  anterior 
  surface 
  for 
  union 
  with 
  the 
  scapula, 
  and 
  a 
  wider, 
  

   thicker 
  antero-lateral 
  surface 
  for 
  union 
  with 
  the 
  humerus. 
  In 
  trans- 
  

   verse 
  measurement 
  the 
  bone 
  is 
  concave, 
  while 
  from 
  front 
  to 
  back 
  it 
  

   is 
  flattened. 
  The 
  scapulae 
  are 
  imperfect 
  ; 
  but 
  that 
  on 
  the 
  left 
  side 
  

   is 
  the 
  better 
  preserved. 
  It 
  has 
  somewhat 
  of 
  a 
  chopper-like 
  shape, 
  

   the 
  part 
  which 
  would 
  correspond 
  to 
  the 
  handle 
  of 
  the 
  chopper 
  

   being 
  directed 
  above 
  the 
  head 
  of 
  the 
  humerus, 
  much 
  like 
  the 
  supra^- 
  

   humeral 
  process 
  of 
  the 
  scapula 
  in 
  Plesiosaurus. 
  The 
  blade 
  of 
  the 
  

   bone 
  is 
  subobovate, 
  with 
  a 
  slight 
  median 
  ridge 
  dividing 
  the 
  surface 
  

   into 
  two 
  nearly 
  equal 
  portions. 
  This 
  ridge 
  terminates 
  posteriorly 
  in 
  

   a 
  thickened, 
  rounded 
  articulation, 
  which 
  contributed 
  with 
  the 
  cora- 
  

   coid 
  to 
  form 
  the 
  glenoid 
  cavity 
  for 
  the 
  humerus. 
  Interior 
  to 
  this, 
  

   though 
  not 
  well 
  seen, 
  is 
  the 
  articular 
  surface 
  which 
  unites 
  the 
  bone 
  

   with 
  the 
  coracoid. 
  The 
  ridge 
  on 
  the 
  bone 
  not 
  improbably 
  indicates 
  the 
  

   area 
  which 
  was 
  overlapped 
  by 
  the 
  clavicle. 
  The 
  length 
  of 
  the 
  blade 
  

   of 
  the 
  scapula 
  is 
  just 
  over 
  1 
  cm. 
  ; 
  its 
  breadth 
  is 
  6 
  mm. 
  ; 
  the 
  length 
  

   of 
  the 
  posterior 
  process 
  cannot 
  be 
  given 
  with 
  certainty, 
  since 
  it 
  is 
  

   partly 
  covered 
  by 
  the 
  head 
  of 
  the 
  humerus 
  ; 
  but 
  it 
  could 
  not 
  have 
  

   been 
  less 
  than 
  3 
  mm. 
  This 
  process 
  ascends 
  at 
  a 
  considerable 
  angle 
  

   above 
  the 
  plane 
  of 
  the 
  base 
  of 
  the 
  bone. 
  As 
  already 
  remarked, 
  the 
  

   Q.J.G.S. 
  No. 
  151. 
  2 
  b 
  

  

  