﻿P. 
  E. 
  Raymond 
  — 
  Beeche^s 
  Classification 
  of 
  Trilobites. 
  197 
  

  

  which 
  has 
  been 
  suggested 
  is 
  the 
  removal 
  of 
  the 
  Calymenidse 
  

   from 
  the 
  Proparia 
  to 
  the 
  Opisthoparia. 
  Not 
  of 
  any 
  great 
  

   importance 
  in 
  itself, 
  such 
  a 
  change 
  reduces 
  an 
  already 
  some- 
  

   what 
  small 
  order 
  to 
  such 
  proportions 
  that 
  nearly 
  all 
  the 
  

   families 
  of 
  trilobites 
  would 
  be 
  grouped 
  in 
  the 
  Opisthoparia 
  and 
  

   we 
  would 
  truly 
  have 
  arrived 
  at 
  the 
  pass 
  which 
  Woods 
  has 
  

   deplored. 
  The 
  arguments 
  can 
  probably 
  be 
  best 
  set 
  forth 
  if 
  

   we 
  take 
  up 
  in 
  order 
  each 
  family 
  whose 
  position 
  in 
  the 
  scheme 
  

   has 
  been 
  questioned. 
  

  

  Hypoparia. 
  

  

  Agnostidce. 
  — 
  Beecher 
  included 
  in 
  this 
  family 
  both 
  Agnostus 
  

   and 
  Miorodisous 
  (Eodiscus), 
  but 
  the 
  remarks 
  which 
  follow 
  

   exclude 
  the 
  Eodiscidse. 
  The 
  members 
  of 
  this 
  family 
  were 
  

   considered 
  by 
  Beecher 
  as 
  the 
  most 
  primitive 
  of 
  trilobites, 
  

   though 
  he 
  recognized 
  in 
  them 
  certain 
  highly 
  specialized 
  and 
  

   even 
  degraded 
  characteristics 
  (see 
  his 
  paper, 
  pp. 
  184-185). 
  He 
  

   stated 
  that 
  the 
  free 
  cheeks 
  were 
  continuous 
  and 
  ventral 
  in 
  

   position, 
  and 
  the 
  suture 
  marginal 
  or 
  ventral. 
  He 
  unfortunately 
  

   furnished 
  no 
  definite 
  proof 
  of 
  these 
  statements, 
  the 
  truth 
  of 
  

   which 
  has 
  been 
  denied 
  by 
  Jaekel,* 
  Lindstrom,f 
  and 
  Holm, 
  and 
  

   questioned 
  by 
  S 
  winner 
  ton 
  .\ 
  

  

  In 
  his 
  article 
  Beecher 
  states 
  : 
  " 
  In 
  Agnostus 
  this 
  feature 
  

   (the 
  suture) 
  has 
  escaped 
  notice. 
  The 
  examination 
  of 
  extensive 
  

   series 
  of 
  Agnostus 
  in 
  the 
  National 
  Museum 
  and 
  in 
  the 
  Museum 
  

   of 
  Comparative 
  Zoology 
  has 
  proved 
  that 
  under 
  favorable 
  con- 
  

   ditions 
  of 
  preservation 
  this 
  genus 
  shows 
  a 
  distinct 
  plate, 
  

   separated 
  from 
  the 
  cranidium 
  by 
  a 
  suture, 
  and 
  it 
  can 
  be 
  com- 
  

   pared 
  only 
  with 
  the 
  free 
  cheeks 
  of 
  other 
  trilobites." 
  Beecher 
  

   neither 
  mentioned 
  the 
  species 
  in 
  which 
  he 
  saw 
  this 
  plate, 
  nor 
  

   did 
  he 
  ever 
  figure 
  it.§ 
  Acting 
  on 
  the 
  above 
  hint, 
  however, 
  I 
  

  

  *Zeitschr. 
  Deutsch. 
  Geol. 
  Ges., 
  vol. 
  lxi, 
  p. 
  387, 
  1909. 
  

  

  fKongl. 
  Svenska 
  Vet. 
  Akad. 
  Handl., 
  xxxiv, 
  No. 
  8, 
  p. 
  10, 
  1901. 
  

  

  JGeol. 
  Mag., 
  Dec. 
  6, 
  vol. 
  ii, 
  p. 
  490, 
  1915. 
  

  

  § 
  Agnostidce. 
  — 
  In 
  regard 
  to 
  the 
  presence 
  of 
  free 
  cheeks 
  in 
  the 
  Agnostidae 
  

   as 
  seen 
  by 
  Beecher, 
  the 
  reason 
  why 
  he 
  " 
  furnished 
  no 
  definite 
  proof 
  of 
  these 
  

   statements" 
  is 
  as 
  follows: 
  Before 
  he 
  had 
  printed 
  his 
  classification 
  of 
  the 
  

   Trilobita 
  he 
  and 
  I 
  had 
  gone 
  over 
  the 
  material 
  in 
  the 
  United 
  States 
  National 
  

   Museum 
  and 
  I 
  distinctly 
  remember 
  that 
  he 
  was 
  especially 
  desirous 
  of 
  seeing 
  

   Hypoparia. 
  Dr. 
  Walcott 
  had 
  turned 
  over 
  to 
  that 
  museum 
  much 
  material 
  

   that 
  he 
  had 
  gathered 
  under 
  auspices 
  of 
  the 
  United 
  States 
  Geological 
  Survey 
  

   and 
  there 
  was 
  considerable 
  material 
  of 
  the 
  genus 
  Agnostus. 
  All 
  of 
  this 
  

   material 
  Beecher 
  looked 
  over, 
  and 
  among 
  the 
  American 
  species 
  of 
  Agnostus 
  

   preserved 
  in 
  shales 
  there 
  was 
  one 
  that 
  seemed 
  to 
  show 
  the 
  presence 
  of 
  free 
  

   cheeks. 
  The 
  evidence 
  at 
  first 
  was 
  not 
  conclusive 
  and 
  he 
  then 
  went 
  over 
  the 
  

   material 
  again 
  and 
  finally 
  succeeded 
  in 
  finding 
  a 
  free 
  cheek 
  in 
  the 
  form 
  of 
  

   an 
  imprint 
  lying 
  alone 
  among 
  the 
  heads 
  and 
  tails 
  of 
  Agnostus. 
  The 
  species 
  

   is 
  now 
  unknown 
  to 
  me. 
  This 
  he 
  showed 
  to 
  me 
  and 
  we 
  agreed 
  that 
  it 
  was 
  

   actually 
  a 
  free 
  cheek 
  of 
  a 
  species 
  of 
  this 
  genus. 
  In 
  width 
  the 
  free 
  cheek 
  was 
  

   linear, 
  almost 
  no 
  thicker 
  than 
  a 
  human 
  hair 
  and 
  without 
  a 
  trace 
  of 
  an 
  eye- 
  

   spot 
  or 
  ornamentation. 
  The 
  reason 
  why 
  he 
  did 
  not 
  figure 
  the 
  specimen 
  was 
  

   because 
  the 
  Cambrian 
  trilobites 
  were 
  reserved 
  for 
  further 
  study 
  by 
  Walcott, 
  

   and 
  it 
  was 
  expected 
  that 
  in 
  the 
  course 
  of 
  time 
  the 
  latter 
  would 
  come 
  upon 
  

   this 
  specimen 
  and 
  figure 
  it 
  in 
  his 
  prospective 
  monograph 
  of 
  Cambrian 
  

   trilobites. 
  — 
  Charles 
  Schu 
  chert. 
  

  

  