﻿4 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  G7 
  

  

  ites 
  fossilis 
  in 
  1804. 
  8 
  Under 
  the 
  rules 
  of 
  nomenclature 
  this 
  name 
  

   had 
  priority, 
  and 
  Miller's 
  name 
  would 
  have 
  to 
  be 
  discarded 
  in 
  its 
  

   favor. 
  Not 
  only 
  so, 
  but 
  as 
  the 
  name 
  Pentacrinus 
  had 
  been 
  attached 
  

   to 
  the 
  (briareus) 
  fossilis 
  type, 
  No. 
  1, 
  long 
  before 
  the 
  time 
  of 
  the 
  

   Austins, 
  it 
  followed 
  that 
  their 
  genus 
  Extracrinus 
  must 
  also 
  go 
  into 
  

   the 
  discard, 
  and 
  all 
  the 
  species 
  which 
  had 
  been 
  ranked 
  under 
  it 
  

   would 
  now 
  have 
  to 
  be 
  listed 
  as 
  the 
  true 
  Pentacrinus. 
  

  

  Furthermore, 
  it 
  was 
  found 
  that 
  the 
  Pentacrinus 
  type 
  No. 
  2 
  was 
  

   covered 
  by 
  the 
  genus 
  Isocrinus 
  Agassiz, 
  1836 
  (von 
  Meyer, 
  1837) 
  : 
  

   so 
  that 
  the 
  species 
  of 
  that 
  type, 
  which 
  included 
  all 
  the 
  Recent 
  

   "Pentacrinus", 
  would 
  have 
  to 
  be 
  written 
  Isocrinus, 
  leaving 
  the 
  

   species 
  of 
  type 
  No. 
  1 
  as 
  the 
  true 
  Pentacrinus, 
  typified 
  by 
  Blumen- 
  

   bach's 
  original 
  species, 
  P. 
  fossilis. 
  

  

  All 
  this 
  history, 
  of 
  which 
  I 
  am 
  giving 
  but 
  a 
  brief 
  abstract, 
  will 
  

   be 
  found 
  fully 
  set 
  forth 
  with 
  ample 
  reference 
  to 
  the 
  original 
  sources, 
  

   in 
  Doctor 
  Bather's 
  paper 
  already 
  mentioned. 
  Thus 
  when 
  in 
  the 
  

   literature 
  the 
  name 
  Pentacrinus 
  is 
  encountered 
  for 
  an 
  existing 
  

   crinoid, 
  or 
  for 
  a 
  fossil 
  species 
  in 
  the 
  works 
  of 
  de 
  Loriol, 
  it 
  means 
  

   Isocrinus 
  ; 
  and 
  where 
  the 
  name 
  " 
  Extracrinus 
  " 
  occurs 
  it 
  should 
  be 
  

   read 
  Pentacrinus. 
  And 
  for 
  the 
  classic 
  name 
  " 
  Pentacrinus 
  briareus 
  " 
  

   there 
  should 
  now 
  be 
  substituted 
  P. 
  fossilis. 
  Quenstedt 
  did 
  not 
  adopt 
  

   the 
  name 
  " 
  Extracrinus," 
  but 
  continued 
  to 
  use 
  the 
  original 
  term 
  for 
  

   both 
  forms. 
  

  

  "With 
  this 
  explanation 
  to 
  obviate 
  confusion 
  over 
  the 
  names, 
  we 
  

   are 
  in 
  position 
  to 
  consider 
  the 
  questions 
  relating 
  to 
  the 
  particular 
  

   forms 
  of 
  the 
  genus 
  suggested 
  by 
  the 
  new 
  material. 
  

  

  According 
  to 
  Quenstedt 
  and 
  de 
  Loriol 
  9 
  the 
  true 
  Pentacrinus 
  

   (type 
  No. 
  1, 
  above) 
  is 
  divisible 
  into 
  two 
  groups, 
  characterized 
  by 
  

   stem 
  characters 
  only, 
  which 
  with 
  our 
  present 
  knowledge 
  would 
  be 
  

   described 
  as 
  follows: 
  

  

  1. 
  P. 
  (briareus) 
  fossils 
  (Blumenbach), 
  1S02. 
  Lower 
  Lias, 
  Dorsetshire, 
  Eng- 
  

   land. 
  

  

  Stem 
  short, 
  sharply 
  pentagonal. 
  Coluniuals 
  alternating, 
  but 
  not 
  strongly 
  

   unequal. 
  Internodals 
  few, 
  from 
  1 
  near 
  the 
  calyx, 
  to 
  3 
  or 
  4 
  distally. 
  Cirri 
  

   large, 
  very 
  long, 
  prismatic 
  or 
  flattened, 
  in 
  whorls 
  of 
  5 
  to 
  every 
  nodal. 
  

  

  2. 
  P. 
  subangulrrtis 
  Miller, 
  1821. 
  Upper 
  and 
  middle 
  Lias, 
  Wurtemburg, 
  

   Germany. 
  

  

  Stem 
  very 
  long, 
  subpentangular 
  or 
  round. 
  Columnals 
  alternating, 
  very 
  

   unequal 
  ; 
  internodals 
  numerous, 
  increasing 
  from 
  the 
  calyx 
  distalwards 
  by 
  

   doubling. 
  Cirri 
  few, 
  small, 
  short 
  and 
  round. 
  

  

  In 
  a 
  good 
  specimen 
  from 
  Holzmaden 
  in 
  my 
  collection 
  the 
  cirrus 
  

   intervals 
  increase 
  from 
  3 
  ossicles 
  (1 
  long 
  and 
  2 
  short) 
  beginning 
  

   with 
  the 
  second 
  large 
  colunmal 
  near 
  the 
  calyx, 
  to 
  7, 
  15, 
  and 
  31 
  

   internodals 
  at 
  about 
  the 
  fifteenth 
  internode, 
  a 
  distance 
  of 
  about 
  30 
  

  

  - 
  Abh. 
  Naturh. 
  No. 
  70, 
  pi. 
  70. 
  

  

  Crin. 
  de 
  la 
  France, 
  vol. 
  2, 
  p. 
  385. 
  

  

  