﻿536 
  MR. 
  F. 
  E. 
  COWPER 
  REED 
  ON 
  THE 
  FOSSILS 
  OF 
  [DeC. 
  1 
  89 
  7, 
  

  

  Bowmani, 
  sp. 
  (3. 
  

  

  , 
  cf. 
  oblongatus, 
  . 
  

  

  Lichas 
  sp. 
  

   Bemopleurides 
  sp. 
  

   SphcBrexochus 
  mirus, 
  Beyr. 
  

   Staurocephalus 
  sp. 
  

   Stygina 
  latifrons, 
  Portl. 
  

   Trinucleus 
  seticomis, 
  His. 
  

   , 
  Tar. 
  

  

  Calymene 
  Blumenbachi, 
  Brongn. 
  

   Gheirurus 
  bimucronatus 
  ?, 
  Murch. 
  

  

  juvenis, 
  Salt. 
  (J 
  clavifrons, 
  Dalm.). 
  

  

  [Pseudosj)k(srexochus] 
  subquadra- 
  

  

  tus, 
  Reed. 
  

   Cybele 
  rugosa, 
  Portl., 
  var. 
  a. 
  

  

  , 
  var. 
  attenuata 
  no 
  v. 
  

  

  Harpes, 
  2 
  spp. 
  

   Illcsnus 
  Bowmani, 
  Salt. 
  

  

  Of 
  the 
  above 
  the 
  Illceni 
  are 
  the 
  most 
  abundant. 
  Besides 
  /. 
  Bow- 
  

   mani 
  there 
  are 
  fragments 
  of 
  a 
  foroi 
  (sp. 
  a) 
  possessing 
  an 
  ornamen- 
  

   tation 
  of 
  small 
  pits 
  distributed 
  with 
  some 
  regularity 
  over 
  the 
  shell, 
  

   with 
  a 
  very 
  finely-punctated 
  surface. 
  But 
  the 
  specimens 
  are 
  too 
  

   imperfect 
  to 
  determine 
  the 
  species. 
  

  

  Another 
  form 
  has 
  the 
  general 
  appearance 
  of 
  /. 
  Bowmani, 
  so 
  far 
  

   as 
  the 
  fragments 
  allow 
  one 
  to 
  distinguish 
  its 
  characters, 
  but 
  the 
  

   pygidium 
  is 
  seen 
  to 
  be 
  bluntly 
  pointed 
  behind 
  when 
  the 
  shell 
  is 
  

   removed 
  and 
  the 
  cast 
  of 
  the 
  under 
  surface 
  displayed 
  to 
  view. 
  

  

  The 
  remaining 
  form, 
  represented 
  by 
  one 
  imperfect 
  pygidium 
  in 
  

   this 
  collection, 
  has 
  the 
  shape 
  and 
  prominent 
  axis 
  of 
  /. 
  oblongatus 
  

   (Angelin), 
  with 
  which 
  it 
  may 
  be 
  compared; 
  but 
  it 
  is 
  not 
  quite 
  

   clear 
  whether 
  the 
  specimen 
  has 
  not 
  suffered 
  crushing 
  and 
  distortion. 
  

  

  Calymene 
  Blumenbachi 
  and 
  Sphcerexoclius 
  mirus 
  are 
  represented 
  

   by 
  several 
  pygidia 
  and 
  head-shields 
  which 
  call 
  for 
  no 
  remarks. 
  

  

  Trinucleus 
  seticomis 
  of 
  the 
  tj'pical 
  Swedish 
  form, 
  without 
  the 
  long 
  

   head-spines 
  of 
  T. 
  BucJdandi, 
  occurs 
  in 
  the 
  limestone, 
  so 
  far 
  as 
  one 
  

   can 
  judge 
  from 
  portions 
  of 
  the 
  fringe 
  and 
  general 
  expansions. 
  But 
  

   in 
  one 
  specimen 
  the 
  three 
  or 
  four 
  uppermost 
  rows 
  of 
  pits 
  or 
  the 
  

   convex 
  portion 
  of 
  the 
  fringe 
  immediately 
  in 
  front 
  of 
  the 
  glabella 
  are 
  

   situated 
  in 
  regularly 
  radiating 
  grooves, 
  giving 
  a 
  very 
  distinctive 
  

   appearance 
  to 
  this 
  part. 
  In 
  other 
  respects 
  the 
  specimen 
  resembles 
  

   the 
  typical 
  T. 
  seticomis, 
  and 
  can 
  only 
  be 
  considered 
  a 
  variety 
  of 
  it. 
  

  

  Cybele 
  rugosa 
  appears 
  to 
  occur, 
  for 
  I 
  can 
  only 
  regard 
  the 
  two 
  

   imperfect 
  pygidia 
  of 
  a 
  Cybele 
  as 
  belonging 
  to 
  this 
  species. 
  In 
  

   ' 
  variety 
  a 
  ' 
  three 
  pairs 
  of 
  small 
  tubercles 
  are 
  situated 
  on 
  the 
  axis, 
  

   just 
  at 
  the 
  inner 
  termination 
  of 
  the 
  incomplete 
  transverse 
  farrows 
  

   which 
  mark 
  out 
  the 
  rings 
  on 
  the 
  axis. 
  This 
  specimen 
  closely 
  

   resembles 
  that 
  figured 
  by 
  Nicholson 
  & 
  Etheridge 
  in 
  their 
  ' 
  Mono- 
  

   graph 
  of 
  the 
  Girvan 
  Silurian 
  Fossils 
  ' 
  (pi. 
  xiv. 
  fig. 
  13) 
  ; 
  while 
  var. 
  

   attenuata 
  has 
  the 
  long 
  attenuated 
  axis 
  of 
  M'Coy's 
  figure 
  (' 
  Syn. 
  Brit. 
  

   Pal. 
  Foss.' 
  pi. 
  i.G, 
  fig. 
  8), 
  but 
  there 
  are 
  three 
  pairs 
  of 
  small 
  tubercles 
  

   on 
  the 
  axis 
  as 
  in 
  the 
  other 
  variety, 
  and 
  the 
  ribs 
  on 
  the 
  lateral 
  lobes 
  

   are 
  narrower, 
  except 
  the 
  outer 
  one, 
  which 
  is 
  flattened 
  and 
  pitted 
  so 
  

   as 
  to 
  give 
  a 
  somewhat 
  wide 
  margin 
  to 
  the 
  upper 
  part 
  of 
  the 
  outer 
  

   edge 
  of 
  the 
  pygidium. 
  Otherwise 
  it 
  is 
  similar 
  to 
  M'Coy's 
  figure. 
  

   It 
  may 
  be 
  designated 
  as 
  var. 
  attenuata. 
  Fragments 
  of 
  the 
  head- 
  

   shields 
  of 
  Cybele 
  are 
  abundant. 
  

  

  Harpes 
  is 
  represented 
  by 
  two 
  fragments 
  belonging 
  to 
  the 
  punc- 
  

   tated 
  border 
  of 
  two 
  species. 
  The 
  punctures 
  in 
  one 
  specimen 
  are 
  

   much 
  coarser 
  and 
  more 
  irregular 
  than 
  in 
  the 
  other, 
  which 
  is 
  uni- 
  

   formly 
  covered 
  with 
  fine 
  minute 
  pits. 
  

  

  