﻿358 
  Forty-seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  as 
  there 
  appears 
  to 
  be 
  a 
  slight 
  fracture 
  and 
  displacement 
  along 
  

   one 
  of 
  them. 
  Two 
  symmetrical 
  pairs 
  diverge 
  laterally 
  over 
  the 
  

   surface 
  of 
  the 
  central 
  plates 
  (c), 
  the 
  posterior 
  pair 
  being 
  the 
  

   shorter; 
  a 
  fourth 
  pair 
  follows 
  the 
  curvature 
  of 
  the 
  median 
  

   occipital 
  plate, 
  just 
  outside 
  of 
  it, 
  curves 
  upward 
  near 
  the 
  post- 
  

   lateral 
  extremities 
  of 
  the 
  shield 
  and 
  gives 
  off 
  two 
  short 
  branches 
  

   to 
  the 
  margin. 
  The 
  further 
  course 
  of 
  these 
  canals 
  cannot 
  be 
  

   made 
  out. 
  

  

  Plates. 
  The 
  ethmoid 
  (a. 
  e., 
  p. 
  e.) 
  has 
  a 
  lanceolate 
  outline 
  and 
  

   no 
  suture 
  between 
  its 
  anterior 
  and 
  posterior 
  divisions 
  can 
  be 
  

   distinguished. 
  The 
  sharp 
  posterior 
  apex 
  of 
  the 
  plate 
  extends 
  

   backwards 
  between 
  the 
  inner 
  margins 
  of 
  the 
  centrals 
  (c), 
  a 
  feature 
  

   in 
  which 
  there 
  is 
  a 
  notable 
  difference 
  from 
  Ooccosteus, 
  though 
  a 
  

   similar 
  arrangement 
  is 
  seen 
  in 
  the 
  genus 
  Homosteus* 
  

  

  The 
  outline 
  of 
  the 
  centrals 
  (c) 
  can 
  be 
  fully 
  traced 
  on 
  one 
  side. 
  

   The 
  median 
  suture 
  extending 
  to 
  the 
  median 
  occipital 
  (m. 
  o.) 
  

   with 
  its 
  characteristic 
  posterior 
  sigma 
  is 
  very 
  clearly 
  defined. 
  

  

  The 
  anterior 
  margins, 
  beginning, 
  as 
  stated, 
  in 
  front 
  of 
  the 
  apex 
  

   of 
  the 
  ethmoid, 
  and 
  the 
  lateral 
  margins, 
  especially 
  that 
  on 
  the 
  

   right 
  hand 
  side, 
  can 
  be 
  traced 
  for 
  their 
  entire 
  course. 
  

  

  The 
  median 
  occipital 
  (m. 
  o.) 
  is 
  large 
  and 
  has 
  the 
  usual 
  sub- 
  

   quadrate 
  form 
  characteristic 
  of 
  Coccosteus. 
  

  

  The 
  orbit 
  on 
  the 
  left 
  side 
  is 
  retained 
  and 
  this 
  helps 
  to 
  establish 
  

   the 
  outline 
  of 
  the 
  pre-orbital 
  plate 
  (p. 
  o.) 
  on 
  that 
  side. 
  

  

  I 
  have 
  marked 
  on 
  the 
  diagram 
  as 
  pre-maxillary 
  (p. 
  mx.) 
  a 
  frag- 
  

   ment 
  lying 
  in 
  front 
  of 
  the 
  pre-orbital 
  {p. 
  o.), 
  though 
  it 
  is 
  not 
  

   clearly 
  separated 
  from 
  the 
  maxillary 
  or 
  infra-orbital 
  (mx) 
  lying 
  

   beneath 
  or 
  outside 
  of 
  the 
  orbit. 
  The 
  plate 
  marked 
  (x) 
  may 
  also 
  

   be 
  a 
  part 
  of 
  the 
  maxillary 
  (mx), 
  for 
  while 
  it 
  is 
  separated 
  from 
  the 
  

   I 
  atter 
  by 
  a 
  deep 
  sinus, 
  it 
  is 
  difficult 
  to 
  decide 
  whether 
  this 
  is 
  a 
  

   sensory 
  canal 
  or 
  a 
  true 
  suture. 
  

  

  The 
  left 
  side 
  of 
  the 
  specimen 
  is 
  covered 
  by 
  a 
  broad 
  expansion 
  

   upon 
  which 
  evidences 
  of 
  sutures 
  are 
  very 
  uncertain. 
  This 
  sur- 
  

   face 
  undoubtedly 
  includes 
  the 
  post-orbital 
  (pt. 
  o.) 
  and 
  marginal 
  

   (m) 
  plates 
  (the 
  latter 
  of 
  which 
  is 
  fairly 
  well 
  defined 
  on 
  the 
  right 
  

   hand 
  side 
  of 
  the 
  specimen) 
  and 
  probably 
  some 
  portion 
  of 
  the 
  

   ventrolaterals 
  (vz.) 
  The 
  plates 
  (marked 
  e. 
  o.) 
  correspond 
  in 
  

  

  * 
  See 
  Traquair's 
  figure 
  of 
  Homosteus, 
  loc. 
  cit. 
  pi. 
  1. 
  fig. 
  1. 
  

  

  