﻿158 
  MR. 
  P. 
  A. 
  BATHER 
  ON 
  TRIGOXOCRINTTS 
  FROM 
  

  

  probably 
  consist 
  of 
  fused 
  basals 
  : 
  but 
  it 
  wholly 
  differs 
  in 
  appearance 
  

   and 
  position 
  from 
  the 
  " 
  article 
  basal 
  " 
  of 
  Eug. 
  caryophyllatus, 
  and 
  

   probably 
  of 
  all 
  Eugeniacrinidse 
  ; 
  nor 
  could 
  it 
  in 
  any 
  case 
  be 
  used 
  as 
  

   a 
  strong 
  argument 
  by 
  Carpenter, 
  since 
  he 
  himself 
  has 
  assigned 
  that 
  

   genus 
  to 
  a 
  different 
  family. 
  

  

  (3) 
  Eidges 
  are 
  well 
  known 
  to 
  be 
  occasionally 
  present 
  on 
  the 
  upper 
  

   surface 
  of 
  the 
  " 
  article 
  basal 
  " 
  in 
  such 
  individuals 
  as 
  have 
  the 
  inter- 
  

   radial 
  sutures 
  well 
  marked. 
  One 
  is 
  not 
  tempted 
  to 
  ascribe 
  to 
  these 
  

   ridges 
  any 
  morphological 
  significance, 
  seeing 
  that 
  their 
  intensity 
  is 
  

   obviously 
  connected 
  with 
  the 
  depth 
  of 
  the 
  suture-groove, 
  and 
  that 
  

   similar 
  ridges 
  occur 
  on 
  the 
  top 
  stem-joint 
  of 
  Apiocrinidse. 
  But, 
  says 
  

   Dr. 
  Carpenter, 
  " 
  in 
  Tetracrinus 
  and 
  Eugeniacrinus 
  the 
  ridges 
  are 
  

   interradial." 
  It 
  is 
  hard 
  to 
  see 
  how 
  they 
  could 
  be 
  otherwise 
  : 
  and 
  for 
  

   the 
  matter 
  of 
  that, 
  it 
  often 
  happens 
  in 
  Apiocrinus 
  elegans, 
  Defr., 
  non 
  

   d'Orb. 
  {—A. 
  Parhinsoni, 
  Schl.), 
  that 
  the 
  top 
  stem-joint 
  has 
  under- 
  

   gone 
  interradial 
  fission, 
  in 
  which 
  case 
  the 
  joint 
  below 
  it 
  shows 
  inter- 
  

   radial 
  ridges 
  *. 
  

  

  (4) 
  Dr. 
  Carpenter 
  says 
  f, 
  " 
  the 
  so-called 
  uppermost 
  stem-joint 
  of 
  

  

  Eugeniacrinidse 
  is 
  pierced 
  by 
  five 
  interradial 
  canals, 
  each 
  of 
  

  

  which 
  forks 
  just 
  below 
  the 
  synostosis 
  of 
  this 
  piece 
  with 
  the 
  radials 
  

   above. 
  In 
  Encrinus, 
  Apiocrinus, 
  Millericrinm, 
  Pentacrinus, 
  Meta- 
  

   crinus, 
  &c, 
  and 
  in 
  the 
  larval 
  Comatulce, 
  each 
  of 
  the 
  basals 
  is 
  perfor- 
  

   ated 
  by 
  one 
  of 
  these 
  bifurcating 
  interradial 
  canals 
  ; 
  and 
  no 
  Crinoid 
  

   is 
  known 
  with 
  these 
  canals 
  situated 
  anywhere 
  else 
  but 
  in 
  the 
  basals. 
  

   They 
  lodge 
  the 
  five 
  primary 
  cords 
  which 
  proceed 
  outwards 
  from 
  the 
  

   chambered 
  organ 
  towards 
  the 
  circular 
  commissure 
  contained 
  within 
  

   the 
  radial 
  pentagon." 
  This 
  is 
  very 
  solid 
  argument, 
  and 
  the 
  major 
  

   premiss 
  will 
  be 
  accepted 
  by 
  everybody 
  ; 
  all 
  depends 
  on 
  the 
  minor. 
  Is 
  

   Dr. 
  Carpenter's 
  description 
  of 
  the 
  structure 
  in 
  Eugeniacrinus 
  correct 
  ? 
  

   He 
  instances 
  no 
  authority, 
  brings 
  forward 
  no 
  evidence, 
  and 
  gives 
  

   hardly 
  any 
  details. 
  

  

  With 
  this 
  it 
  is 
  interesting 
  to 
  compare 
  the 
  explicit 
  account 
  of 
  Prof 
  

   K. 
  v. 
  Zittelt, 
  based 
  on 
  evidence 
  similar 
  to 
  that 
  previously 
  published 
  

   by 
  Prof. 
  E. 
  Beyrich 
  §, 
  Dr. 
  Carpenter 
  alludes 
  to 
  Beyrich's 
  view 
  || 
  ; 
  but 
  

   I 
  cannot 
  find 
  that 
  he 
  has 
  anywhere 
  seriously 
  discussed 
  it, 
  or 
  examined 
  

   the 
  evidence. 
  Yon 
  Zittel's 
  account 
  is 
  as 
  follows 
  : 
  — 
  " 
  The 
  central 
  

   canal 
  of 
  the 
  stem 
  enters 
  the 
  massive 
  calyx 
  composed 
  of 
  the 
  anchy- 
  

   losed 
  radials 
  ; 
  it 
  gradually 
  broadens 
  upward, 
  and 
  at 
  a 
  short 
  dis- 
  

   tance 
  gives 
  off 
  5 
  interradial 
  canals. 
  These 
  run 
  under 
  the 
  floor 
  

   of 
  the 
  visceral 
  cavity 
  and 
  very 
  soon 
  bifurcate. 
  The 
  branches 
  

   enter 
  the 
  radials, 
  unite 
  there, 
  each 
  with 
  the 
  converging 
  branch 
  of 
  an 
  

   adjacent 
  basal 
  canal; 
  they 
  then 
  proceed, 
  close 
  to 
  one 
  another, 
  

  

  * 
  See 
  also 
  J. 
  S. 
  Miller, 
  * 
  Nat. 
  Hist. 
  Crin.' 
  p. 
  32, 
  line 
  9 
  et 
  scq. 
  pi. 
  vii. 
  figs. 
  1-6 
  

   and 
  8-10. 
  

  

  t 
  Absence 
  of 
  Basals, 
  &c, 
  he. 
  cit. 
  p. 
  329. 
  

  

  \ 
  Handb. 
  d. 
  Palaont. 
  p. 
  385. 
  

  

  § 
  Zeitscbr. 
  deutsch. 
  geol. 
  Ges. 
  xxi. 
  p. 
  835 
  (Berlin, 
  1869), 
  Protokoll 
  d. 
  Sitzung, 
  

   15 
  September: 
  " 
  Herr 
  Beyrich 
  legte 
  Praparate 
  von 
  Eugeniacrinuskelchen 
  vor,- 
  

   u. 
  s. 
  w." 
  

  

  I 
  Absence 
  of 
  Basals, 
  &c, 
  loc. 
  cit. 
  p. 
  327. 
  

  

  