﻿2 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  07 
  

  

  derful 
  specimens 
  of 
  the 
  species 
  to 
  which 
  this 
  probably 
  belongs 
  have 
  

   been 
  obtained 
  in 
  various 
  European 
  localities 
  — 
  one 
  of 
  the 
  finest 
  being 
  

   on 
  exhibition 
  in 
  the 
  hall 
  of 
  Invertebrate 
  Paleontology 
  in 
  the 
  United 
  

   States 
  National 
  Museum, 
  having 
  complete 
  arms 
  15 
  inches 
  long, 
  and 
  

   5 
  feet 
  of 
  stem 
  attached 
  — 
  none 
  of 
  them 
  exhibit 
  such 
  perfection 
  in 
  fine 
  

   structural 
  details 
  as 
  this, 
  especially 
  in 
  the 
  sharp 
  definition 
  of 
  the 
  

   pinnules, 
  as 
  shown 
  b}^ 
  the 
  figure 
  herewith. 
  The 
  condition 
  of 
  this 
  

   specimen 
  indicates 
  that 
  it 
  was 
  part 
  of 
  a 
  considerable 
  colony, 
  in 
  which 
  

   a 
  lar^e 
  number 
  of 
  these 
  crinoids 
  were 
  imbedded 
  together, 
  as 
  is 
  the 
  

   case 
  at 
  some 
  of 
  the 
  European 
  localities. 
  

  

  The 
  second 
  locality 
  is 
  about 
  125 
  miles 
  east 
  of 
  the 
  first, 
  near 
  the 
  

   international 
  boundary 
  line, 
  on 
  a 
  tributary 
  to 
  Overthrust 
  Creek, 
  1% 
  

   miles 
  above 
  its 
  mouth, 
  and 
  about 
  8 
  miles 
  west 
  of 
  the 
  one 
  hundred 
  and 
  

   * 
  forty-first 
  meridian. 
  A. 
  G. 
  Madclren, 
  while 
  engaged 
  in 
  geological 
  

   investigations 
  along 
  the 
  Canada-Alaska 
  boundary 
  during 
  1911 
  and 
  

   1912, 
  found 
  at 
  this 
  locality 
  a 
  crinoid 
  bed 
  composed 
  of 
  fragments 
  of 
  

   the 
  same 
  Pentacrinus 
  as 
  the 
  Black 
  Island 
  specimen, 
  in 
  a 
  formation 
  

   largely 
  made 
  up 
  of 
  black 
  shales 
  which 
  are 
  probably 
  the 
  equivalent 
  

   of 
  the 
  Kingak 
  shale. 
  3 
  These 
  remains 
  consist 
  of 
  numerous 
  column 
  

   and 
  arm 
  fragments 
  of 
  large 
  size, 
  rather 
  closely 
  packed 
  together, 
  in- 
  

   dicating 
  a 
  bed 
  of 
  considerable 
  extent, 
  in 
  which, 
  however, 
  the 
  speci- 
  

   mens 
  lack 
  the 
  fine 
  preservation 
  of 
  that 
  of 
  locality 
  1. 
  The 
  matrix 
  

   is 
  highly 
  ferruginous, 
  with 
  much 
  oxidation 
  at 
  the 
  surface 
  by 
  which 
  

   the 
  structural 
  details 
  are 
  destroyed, 
  except 
  in 
  some 
  of 
  the 
  column 
  

   fragments, 
  which 
  have 
  the 
  joint-faces 
  well 
  preserved, 
  showing 
  the 
  

   petaloid 
  sectors 
  characteristic 
  of 
  the 
  genus. 
  

  

  There 
  is 
  a 
  general 
  similarity 
  in 
  size 
  and 
  appearance 
  of 
  the 
  parts 
  

   recovered 
  from 
  the 
  two 
  localities, 
  which 
  indicates 
  the 
  probability 
  of 
  

   their 
  being 
  of 
  the 
  same 
  species. 
  They 
  are 
  larger 
  than 
  the 
  corre- 
  

   sponding 
  parts 
  of 
  specimens 
  as 
  usually 
  found 
  at 
  Lyme-Regis 
  in 
  

   Dorsetshire, 
  England, 
  but 
  not 
  of 
  greater 
  size 
  than 
  that 
  of 
  many 
  

   specimens 
  from 
  the 
  Wurtemburg 
  localities. 
  

  

  Among 
  Mesozoic 
  crinoids 
  no 
  genus 
  has 
  attracted 
  more 
  attention, 
  

   both 
  in 
  the 
  literature 
  and 
  in 
  the 
  rocks, 
  than 
  Pentacrinus 
  of 
  the 
  lower 
  

   Jurassic. 
  From 
  what 
  has 
  been 
  learned 
  in 
  recent 
  years, 
  it 
  probably 
  

   had 
  a 
  wider 
  distribution 
  than 
  any 
  other. 
  In 
  view 
  of 
  this 
  fact, 
  and 
  

   of 
  the 
  evidence 
  as 
  disclosed 
  by 
  the 
  material 
  now 
  before 
  us 
  of 
  its 
  great 
  

   abundance 
  in 
  a 
  region 
  where 
  it 
  was 
  least 
  expected, 
  I 
  have 
  thought 
  

   it 
  well, 
  for 
  the 
  benefit 
  of 
  those 
  who 
  may 
  not 
  have 
  convenient 
  access 
  

   !■> 
  the 
  publications, 
  to 
  give 
  a 
  brief 
  summary 
  of 
  the 
  leading 
  facts 
  rela- 
  

   tive 
  to 
  the 
  genus. 
  The 
  chief 
  descriptive 
  matter 
  may 
  be 
  found 
  in 
  

   the 
  works 
  of 
  J. 
  S. 
  Miller, 
  Quenstedt, 
  de 
  Loriol, 
  and 
  P. 
  H. 
  Carpenter; 
  

   but 
  for 
  a 
  comprehensive 
  and 
  lucid 
  exposition 
  of 
  the 
  genus 
  and 
  the 
  

  

  [,/effingwell, 
  same 
  reference, 
  p. 
  120. 
  

  

  