﻿292 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  

  

  differs 
  from 
  it 
  in 
  the 
  more 
  triangular 
  form 
  of 
  that 
  part, 
  and 
  in 
  the 
  

   much 
  more 
  prominent 
  basal 
  lobes. 
  It 
  must 
  have 
  had 
  very 
  short 
  

   spines 
  to 
  the 
  head-angles, 
  if 
  any. 
  There 
  is 
  no 
  margin 
  in 
  front 
  of 
  

   the 
  glabella. 
  The 
  eyes 
  are 
  small, 
  placed 
  centrally 
  on 
  the 
  cheek, 
  

   not 
  in 
  advance 
  of 
  this 
  position. 
  The 
  tail 
  has 
  a 
  broad 
  stout 
  mucro. 
  

   Side-ribs 
  about 
  six 
  ; 
  these 
  are 
  flat, 
  slightly 
  arched, 
  and 
  directed 
  

   obliquely 
  backward 
  ; 
  they 
  nearly 
  reach 
  the 
  narrow 
  flat 
  margin, 
  and 
  

   are 
  duplicate 
  throughout. 
  The 
  sides 
  are 
  rather 
  flat, 
  but 
  become 
  

   tumid 
  where 
  they 
  run 
  into 
  the 
  broad 
  base 
  of 
  the 
  thick 
  recurved 
  

   mucro, 
  which 
  was 
  probably, 
  when 
  perfect, 
  as 
  long 
  as 
  the 
  tail 
  itself. 
  

   P. 
  socialis 
  has 
  a 
  more 
  slender 
  and 
  less 
  recurved 
  spine 
  ; 
  but 
  the 
  

   species 
  are 
  closely 
  allied. 
  

  

  5. 
  Myocaris 
  Ltttraria, 
  gen. 
  et 
  spec, 
  nov., 
  Salter, 
  Geol. 
  Mag. 
  vol. 
  i. 
  

   p. 
  11. 
  fig. 
  4. 
  

  

  We 
  have 
  only 
  the 
  interior 
  cast 
  of 
  this 
  curious 
  fossil 
  ; 
  and 
  as 
  there 
  

   is 
  no 
  room 
  to 
  figure 
  it 
  here, 
  I 
  must 
  refer 
  to 
  the 
  first 
  number 
  of 
  the 
  

   ' 
  Geological 
  Magazine 
  ' 
  for 
  details. 
  

  

  It 
  is 
  closely 
  allied 
  to 
  the 
  Ceratiocaris, 
  an 
  Upper 
  Silurian 
  genus 
  of 
  

   bivalve 
  Crustacea, 
  from 
  which 
  its 
  deep 
  cervical 
  furrow, 
  indicated 
  on 
  

   the 
  cast, 
  and 
  reaching 
  from 
  a 
  point 
  in 
  advance 
  of 
  the 
  umbo 
  to 
  some 
  

   distance 
  backwards, 
  separates 
  it. 
  There 
  are 
  so 
  many 
  other 
  characters 
  

   of 
  habit 
  — 
  the 
  deeply 
  emarginate 
  anterior 
  border, 
  the 
  strongly 
  ridged 
  

   and 
  ornamented 
  posterior 
  slope, 
  &c. 
  — 
  that 
  I 
  cannot 
  doubt 
  it 
  is 
  a 
  

   distinct 
  genus. 
  

  

  The 
  strong 
  internal 
  subcardinal 
  ridge, 
  marking 
  the 
  position 
  

   of 
  the 
  cervical 
  furrow, 
  leads 
  me 
  to 
  suspect 
  that 
  Mibieria*, 
  a 
  Lower 
  

   Silurian 
  genus 
  which 
  has 
  not 
  yet 
  found 
  its 
  place, 
  may 
  be 
  a 
  cognate 
  

   form. 
  A 
  univalve 
  carapace 
  would 
  be 
  nothing 
  remarkable 
  among 
  

   the 
  allies 
  of 
  Nebalia, 
  but 
  is 
  very 
  puzzling 
  if 
  referred 
  to 
  Lamellibranchs, 
  

   while 
  the 
  whole 
  aspect 
  is 
  unlike 
  that 
  of 
  any 
  of 
  the 
  Calyptra?iform 
  

   shells. 
  I 
  think 
  we 
  may 
  have 
  here 
  the 
  true 
  affinity, 
  but 
  the 
  suggestion 
  

   is 
  only 
  given 
  to 
  induce 
  research. 
  The 
  strong 
  muscular 
  scar 
  behind 
  

   the 
  beak 
  is 
  against 
  it. 
  

  

  BRACHIOPODA. 
  

  

  One 
  of 
  the 
  most 
  interesting 
  discoveries 
  of 
  Marie 
  Rouault 
  in 
  the 
  

   rocks 
  of 
  Normandy 
  was 
  without 
  doubt 
  that 
  of 
  the 
  group 
  of 
  large 
  

   Lingulce 
  which 
  he 
  describes 
  from 
  the 
  Armorican 
  Grit 
  of 
  Montfort, 
  

   Guichen, 
  Soulevache, 
  &c, 
  which 
  grit 
  also 
  contains 
  the 
  fucoids 
  above 
  

   cited. 
  M. 
  Rouault 
  describes 
  three 
  species 
  of 
  Lingvlce, 
  all 
  of 
  which 
  

   I 
  think 
  are 
  identical 
  with 
  ours. 
  

  

  1. 
  Lingula 
  Lesueuri, 
  Rouault. 
  PI. 
  XVII. 
  fig. 
  1. 
  Marie 
  Rouault, 
  

   Bull. 
  Soc. 
  Geol. 
  Fr. 
  2nd 
  ser. 
  vol. 
  viii. 
  p. 
  727. 
  

  

  There 
  cannot 
  be 
  much 
  doubt 
  of 
  this 
  elongate 
  species. 
  It 
  is 
  fur- 
  

  

  * 
  R. 
  pholad/formis, 
  Sliarpe, 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  ix. 
  pi. 
  9. 
  fig. 
  17, 
  and 
  

   E. 
  complanata, 
  Salter, 
  ' 
  Siluria,' 
  2nd 
  edit. 
  p. 
  50, 
  woodcuts 
  of 
  Foss. 
  8. 
  fig. 
  3. 
  (This 
  

   last 
  was 
  erroneously 
  called 
  Bedonia 
  in 
  the 
  text 
  ; 
  see 
  Errata.) 
  

  

  