﻿T. 
  DAVIDSON 
  AND 
  W. 
  KING 
  ON 
  THE 
  TRIMERELLIDiG. 
  125 
  

  

  so-termed 
  Obolus 
  Davidsoni 
  which 
  had 
  been 
  discovered 
  in 
  the 
  same 
  

   island 
  *. 
  

  

  For 
  the 
  first 
  time, 
  in. 
  1868 
  the 
  public 
  became 
  acquainted 
  with 
  the 
  

   fact 
  that 
  an 
  objection 
  had 
  been 
  made 
  by 
  Prof. 
  Hall 
  against 
  the 
  

   generic 
  allocation 
  of 
  the 
  so-termed 
  Obolus 
  Davidsoni, 
  though 
  

   (bowing 
  to 
  the 
  opinion 
  of 
  other 
  authorities) 
  he 
  was 
  induced 
  to 
  name 
  

   an 
  allied 
  species 
  Obolus 
  Conradif. 
  

  

  In 
  1870, 
  Dall, 
  from 
  not 
  being 
  well 
  acquainted 
  with 
  the 
  characters 
  

   npon 
  which 
  Billings 
  had 
  founded 
  his 
  genus 
  Trimerella, 
  and 
  only 
  

   having 
  before 
  him 
  Lindstrom's 
  description 
  of 
  the 
  Gotland 
  specimens 
  

   above 
  referred 
  to, 
  was 
  led 
  to 
  propose 
  for 
  the 
  latter 
  the 
  separate 
  

   generic 
  designation, 
  Gotlandia%. 
  

  

  All 
  along 
  our 
  friends 
  were 
  either 
  supplying 
  us 
  with 
  specimens, 
  or 
  

   with 
  an 
  account 
  of 
  their 
  discoveries 
  ; 
  so 
  that, 
  with 
  close 
  attention 
  to 
  

   both, 
  we 
  felt 
  justified 
  in 
  believing 
  ourselves 
  enabled 
  to 
  throw 
  addi- 
  

   tional 
  light 
  on 
  the 
  group. 
  In 
  the 
  mean 
  time 
  others 
  were 
  still 
  

   working 
  on 
  the 
  same 
  subject. 
  Hall 
  brought 
  out 
  a 
  short 
  notice, 
  in 
  

   the 
  early 
  part 
  of 
  the 
  summer 
  of 
  1871, 
  which 
  contained 
  a 
  description, 
  

   with 
  names, 
  of 
  his 
  proposed 
  genera 
  Rliynobolus 
  and 
  Dinobolus§. 
  

   Dall 
  published 
  a 
  second 
  paper 
  giving 
  further 
  details 
  (already 
  known 
  

   to 
  ourselves) 
  on 
  the 
  internal 
  characters 
  of 
  Trimerella, 
  abandoning 
  

   at 
  the 
  same 
  time 
  his 
  genus 
  Gotlandia. 
  In 
  this 
  paper 
  Dall 
  briefly 
  

   referred 
  to 
  the 
  different 
  known 
  species 
  of 
  Trimerella, 
  and 
  added 
  two 
  

   or 
  three 
  new 
  ones 
  || 
  . 
  

  

  During 
  the 
  same 
  year 
  Meek 
  published 
  a 
  description 
  of 
  Trimerella 
  

   ohioensis 
  ^[ 
  ; 
  and 
  Billings 
  brought 
  out 
  a 
  supplement 
  containing 
  a 
  fuller 
  

   description 
  of 
  his 
  T. 
  acuminata** 
  ; 
  while, 
  in 
  the 
  same 
  year, 
  Quensteclt 
  

   briefly 
  noticed 
  the 
  genus 
  Trimerella, 
  along 
  with 
  Obolus, 
  Schmidt 
  ia, 
  

   Obolella, 
  and 
  Acritesff. 
  

  

  On 
  the 
  29th 
  of 
  December, 
  1871, 
  Billings 
  published 
  a 
  short 
  notice 
  

   of 
  a 
  new 
  genus, 
  MonomereJXa, 
  which, 
  he 
  intimated, 
  would 
  be 
  soon 
  

   fully 
  described, 
  and 
  illustrated 
  by 
  us 
  from 
  both 
  Canadian 
  and 
  

   Swedish 
  specimens. 
  He 
  also 
  proposed 
  another 
  genus 
  for 
  his 
  Obolus 
  

   canadensis 
  under 
  the 
  name 
  Obolelluui%^.. 
  

  

  In 
  April, 
  1872, 
  Hall 
  published 
  a 
  reissue 
  of 
  his 
  paper 
  " 
  printed 
  in 
  

   March, 
  1871," 
  to 
  which 
  is 
  added 
  a 
  plate 
  illustrating 
  the 
  interior 
  of 
  

   Trimerella, 
  and 
  the 
  ventral 
  valve 
  of 
  his 
  so-termed 
  genus 
  Rliynobolus. 
  

   In 
  the 
  same 
  month, 
  Billings 
  brought 
  out 
  a 
  fuller 
  account, 
  with 
  

   figures, 
  of 
  his 
  genus 
  Obolellina§§. 
  

  

  * 
  Ofv. 
  Vet. 
  Ak. 
  Forh. 
  vol. 
  xxiv. 
  p. 
  253, 
  1867 
  ; 
  and 
  Geol. 
  Mag. 
  vol, 
  v. 
  p. 
  441, 
  

   1868. 
  l 
  fe 
  1 
  ' 
  

  

  t 
  Twentieth 
  Annual 
  Report 
  of 
  the 
  Regents 
  of 
  the 
  University 
  of 
  the 
  State 
  of 
  

   New 
  York, 
  p. 
  368, 
  1868. 
  

  

  I 
  American 
  Journal 
  of 
  Conchology, 
  vol. 
  vi. 
  p. 
  160, 
  1870. 
  

   § 
  Notes 
  on 
  some 
  new 
  or 
  imperfectly 
  known 
  forms 
  among 
  the 
  Brachiopodn 
  : 
  

   March 
  1871 
  ; 
  and 
  Neues 
  Jahrbuch, 
  p. 
  989, 
  1871. 
  

  

  || 
  American 
  Journal 
  of 
  Conchology, 
  vol. 
  vii. 
  p. 
  79, 
  1871. 
  

   ^[ 
  American 
  Journal 
  of 
  Science 
  and 
  Art, 
  vol. 
  i. 
  3rd 
  ser. 
  p. 
  305, 
  April 
  1871. 
  

   ** 
  Ibid. 
  June 
  1871 
  ; 
  and 
  Annals 
  and 
  Mag. 
  of 
  Nat. 
  Hist. 
  4th 
  ser. 
  vol. 
  viii. 
  

   August 
  1871. 
  

  

  ft 
  Petrefactenkunde 
  Deutschlands, 
  p. 
  669, 
  &c. 
  1871. 
  

  

  tt 
  Canadian 
  Naturalist, 
  New 
  Series, 
  vol. 
  vi 
  . 
  p. 
  220, 
  1871. 
  §§ 
  Ibid. 
  April 
  1872. 
  

   Q. 
  J. 
  G.S. 
  No. 
  118. 
  L 
  

  

  