﻿PLATE 
  XXXI 
  V. 
  

  

  LlCHAS 
  BKEVICEPS 
  Hall. 
  

  

  Page 
  197. 
  

  

  Fig. 
  1. 
  The 
  upper 
  surface 
  of 
  au 
  imperfect 
  head 
  ; 
  the 
  typical 
  form 
  of 
  the 
  Species. 
  

  

  Fig. 
  1 
  a. 
  Au 
  eulargemeut 
  of 
  the 
  surface 
  of 
  the 
  glabella. 
  

  

  Fig. 
  2. 
  Profile 
  view 
  of 
  the 
  same, 
  showing 
  the 
  elevation 
  of 
  the 
  glabellar 
  lobe. 
  

  

  Fig. 
  3. 
  An 
  enlargement 
  of 
  the 
  eye. 
  

  

  Fig. 
  4. 
  An 
  imperfect 
  thorax 
  and 
  pygidium 
  ; 
  the 
  anterior 
  part 
  of 
  the 
  figure 
  is 
  

  

  restored 
  in 
  outline. 
  

   Fig. 
  5. 
  The 
  lower 
  surface 
  of 
  a 
  large 
  imperfect 
  pygidium, 
  showing 
  the 
  striae 
  of 
  

  

  the 
  enfolded 
  border. 
  

   Fig. 
  6. 
  The 
  upper 
  surface 
  of 
  a 
  smaller 
  imperfect 
  pygidium, 
  restored 
  in 
  outline. 
  

   Fig. 
  7. 
  The 
  central 
  portion 
  of 
  a 
  large 
  glabella 
  ; 
  the 
  outline 
  is 
  carried 
  out 
  to 
  

  

  correspond 
  with 
  the 
  specimen 
  fig. 
  1 
  . 
  

  

  Lichas 
  Boltoni 
  {Bigsby) 
  var. 
  Occidentalis 
  Hall. 
  

  

  Page 
  198. 
  

  

  Fig. 
  8. 
  The 
  lower 
  side 
  of 
  a 
  large 
  perfect 
  pygidium, 
  showing 
  the 
  broad 
  inner 
  

   lining 
  of 
  the 
  border 
  with 
  its 
  characteristic 
  markings. 
  

  

  Fig. 
  9. 
  The 
  upper 
  side 
  of 
  a 
  smaller 
  imperfect 
  pygidium. 
  The 
  separation 
  

   between 
  the 
  lobe 
  of 
  the 
  axis 
  and 
  its 
  continuation 
  on 
  the 
  marginal 
  

   expansion, 
  is 
  due 
  to 
  accidental 
  pressure 
  and 
  partial 
  distortion 
  of 
  

   the 
  parts. 
  

  

  Fig. 
  10. 
  The 
  lower 
  surface 
  of 
  a 
  smaller 
  pygidium, 
  showing 
  similar 
  characters 
  

   to 
  fig. 
  8, 
  except 
  that 
  it 
  is 
  more 
  rounded 
  on 
  the 
  posterior 
  margin. 
  

  

  Fig. 
  11. 
  The 
  hypostoma 
  of 
  a 
  specimen, 
  probably 
  of 
  this 
  variety, 
  resembling 
  

   those 
  from 
  the 
  Niagara 
  shale 
  of 
  New 
  York. 
  

  

  Lichas 
  sp.f 
  

  

  Page 
  199. 
  

  

  Fig. 
  12. 
  The 
  anterior 
  extension 
  of 
  a 
  head 
  of 
  undetermined 
  specific 
  relations 
  

   belonging 
  to 
  this 
  genus. 
  

  

  Dalmanites 
  verrucosus 
  Hall. 
  

  

  Page 
  195. 
  

  

  Fig. 
  13. 
  The 
  lower 
  surface 
  of 
  the 
  marginal 
  rim 
  of 
  the 
  head, 
  for 
  comparison 
  

   with 
  fig. 
  2 
  of 
  PI. 
  33. 
  

  

  Fig. 
  14. 
  The 
  inner 
  side 
  of 
  the 
  crust 
  of 
  a 
  pygidium, 
  showing 
  the 
  points 
  of 
  

   attachment 
  for 
  natatory 
  organs.* 
  

  

  Fig. 
  15. 
  Profile 
  view, 
  looking 
  across 
  the 
  elevation 
  of 
  these 
  processes 
  of 
  attach- 
  

   ment, 
  and 
  of 
  the 
  ridge 
  corresponding 
  to 
  the 
  dorsal 
  furrow 
  of 
  the 
  

   exterior. 
  

  

  *See 
  a 
  paper 
  in 
  this 
  Report, 
  on 
  the 
  Discovery 
  of 
  the 
  Remains 
  of 
  Natatory 
  and 
  Bran- 
  

   chial 
  Appendages 
  of 
  TriloMtes, 
  by 
  C. 
  D. 
  Walcott. 
  

  

  