﻿THE 
  

  

  157 
  

  

  as 
  in 
  Eudesicrinus 
  *. 
  Specimen 
  A 
  shows 
  at 
  its 
  aboral 
  end 
  a 
  similar, 
  

   deep, 
  narrow, 
  circular 
  cavity. 
  We 
  might 
  suppose 
  that 
  the 
  joint 
  of 
  

   the 
  stem 
  succeeding 
  this 
  was 
  partially 
  excavated 
  for 
  the 
  reception 
  of 
  

   a 
  portion 
  of 
  the 
  chambered 
  organ 
  ; 
  but 
  a 
  comparison 
  with 
  the 
  more 
  

   closely 
  allied 
  forms 
  of 
  Eugeniacrinidse 
  suggests 
  rather 
  that 
  the 
  

   upper 
  part 
  of 
  the 
  top 
  stem-joint 
  was 
  inserted 
  in 
  this 
  cavity. 
  What- 
  

   ever 
  was 
  the 
  mode 
  of 
  union, 
  there 
  are 
  now 
  no 
  traces 
  of 
  a 
  ridged 
  sutural 
  

   surface. 
  So 
  far 
  Trigonocrinus 
  approaches 
  Phyllocrinus 
  ; 
  but 
  from 
  

   all 
  the 
  Eugeniacrinidfe 
  it 
  appears 
  to 
  differ 
  in 
  the 
  presence 
  of 
  a 
  basal 
  

   ring. 
  De 
  Loriol 
  says 
  of 
  the 
  Eugeniacrinidae 
  that 
  there 
  are 
  no 
  

   basals 
  ; 
  the 
  radials, 
  he 
  says, 
  repose 
  directly 
  on 
  an 
  " 
  article 
  basal." 
  

   This 
  " 
  article 
  basal 
  " 
  is, 
  according 
  to 
  him, 
  the 
  top 
  stem-joint 
  ; 
  in 
  

   some 
  species 
  it 
  may 
  possibly 
  have 
  received 
  a 
  small 
  portion 
  of 
  the 
  

   chambered 
  organ 
  — 
  e. 
  g. 
  Eug. 
  nutans, 
  Goldfuss, 
  Tetracr. 
  moniliformis, 
  

   Minister, 
  and 
  Eug. 
  mayalis, 
  Moriere. 
  This, 
  however, 
  is 
  very 
  doubt- 
  

   ful, 
  and 
  it 
  is 
  certain 
  that 
  in 
  Eug. 
  caryophyllatus, 
  Schloth., 
  Eug. 
  Du- 
  

   mortieri, 
  de 
  L., 
  Eug. 
  Moussoni, 
  Desor, 
  Eug. 
  crenulatus, 
  d'Orb., 
  Eug. 
  

   aberrans, 
  de 
  L., 
  and 
  in 
  most 
  if 
  not 
  in 
  all 
  of 
  the 
  Phyllocrini, 
  the 
  

   chambered 
  organ 
  was 
  situated 
  within 
  the 
  radial 
  circlet 
  far 
  above 
  

   the 
  " 
  article 
  basal." 
  The 
  idea 
  that 
  basals 
  are 
  entirely 
  unrepre- 
  

   sented 
  is, 
  however, 
  quite 
  opposed 
  to 
  our 
  present 
  knowledge 
  of 
  

   crinoid 
  morphology. 
  The 
  question 
  to 
  be 
  answered 
  therefore 
  is 
  : 
  — 
  

   Where 
  are 
  the 
  basals 
  in 
  Eugeniacrinidae 
  ? 
  

  

  Dr. 
  Carpenter 
  supposes 
  that 
  the 
  " 
  article 
  basal 
  " 
  consists 
  of 
  anchy- 
  

   losed 
  basals 
  f. 
  His 
  arguments 
  are 
  (1) 
  analogy 
  with 
  JRhizocrinus 
  and 
  

   JBathycrinus, 
  (2) 
  doubtful 
  homology 
  with 
  Eudesicrinus 
  and 
  Holopus, 
  

   (3) 
  interradial 
  ridges 
  on 
  upper 
  surface 
  of 
  " 
  article 
  basal 
  " 
  in 
  Eugenia- 
  

   crinus 
  and 
  Tetracrinus, 
  (4) 
  arrangement 
  of 
  internal 
  canals. 
  I 
  shall 
  

   consider 
  these 
  in 
  order. 
  

  

  (1) 
  This 
  argument 
  is 
  only 
  of 
  value 
  as 
  showing 
  how 
  forms 
  once 
  

   supposed 
  to 
  be 
  without 
  basals 
  have 
  been 
  proved 
  to 
  possess 
  them. 
  

   J. 
  S. 
  Miller 
  likewise 
  supposed 
  that 
  the 
  " 
  article 
  basal 
  " 
  in 
  Eugenia- 
  

   crinus 
  represented 
  basals. 
  He, 
  however, 
  imagined 
  that 
  he 
  had 
  

   before 
  him 
  young 
  individuals, 
  " 
  in 
  which 
  an 
  insufficient 
  calcareous 
  

   secretion 
  has 
  not 
  as 
  yet 
  distinctly 
  separated 
  the 
  plates, 
  they 
  might 
  

   very 
  possibly 
  assume 
  the 
  regular 
  character 
  of 
  the 
  genus 
  Encrinites 
  

   in 
  a 
  more 
  advanced 
  stage 
  of 
  their 
  growth 
  "J. 
  Dr. 
  Carpenter's 
  hypo- 
  

   thesis 
  is 
  the 
  converse 
  of 
  Miller's. 
  To 
  prove 
  Miller 
  right, 
  we 
  should 
  

   require 
  older 
  specimens 
  in 
  which 
  the 
  sutures 
  were 
  becoming 
  evident. 
  

   Carpenter, 
  on 
  the 
  other 
  hand, 
  could 
  prove 
  his 
  case 
  by 
  producing 
  

   young 
  specimens 
  in 
  which 
  the 
  sutures 
  had 
  not 
  yet 
  been 
  obscured. 
  

   No 
  such 
  specimens, 
  old 
  or 
  young, 
  have 
  yet 
  been 
  found. 
  

  

  (2) 
  The 
  top 
  part 
  of 
  the 
  support 
  in 
  Eudesicrinus 
  does, 
  it 
  is 
  true, 
  

  

  * 
  De 
  Loriol, 
  ' 
  Pal. 
  Franc;.' 
  loo. 
  cit 
  p. 
  161. 
  

  

  t 
  P. 
  H. 
  Carpenter, 
  " 
  On 
  the 
  Supposed 
  Absence 
  of 
  Basals," 
  &c., 
  loo. 
  cit. 
  p. 
  329 
  ; 
  

   and 
  Eeport 
  ' 
  Challenger 
  ' 
  Crinoidea, 
  I. 
  Stalked 
  Crinoids, 
  p. 
  227. 
  

  

  \ 
  ' 
  Natural 
  History 
  of 
  the 
  Crinoidea,' 
  Bristol, 
  1820, 
  p. 
  113. 
  In 
  young 
  Encrinus 
  

   gracilis 
  the 
  sutures 
  between 
  the 
  basals 
  are 
  invisible; 
  vide 
  E. 
  Beyrich, 
  "Ueberdie 
  

   Crinoideen 
  des 
  Muschelkalks," 
  Abh. 
  d. 
  k. 
  Akad. 
  d. 
  Wiss. 
  Berlin, 
  Phys.-Kl. 
  No. 
  1, 
  

   pp. 
  1-49, 
  pis. 
  i. 
  & 
  ii. 
  

  

  