﻿22 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  6T 
  

  

  20 
  mm. 
  long. 
  Columnals 
  in 
  circular 
  neck 
  average 
  .17 
  mm. 
  long,, 
  

   except 
  where 
  increased 
  by 
  coalescing 
  to 
  twice 
  that 
  length. 
  

  

  This 
  species 
  is 
  of 
  interest 
  as 
  giving 
  us 
  an 
  additional 
  Devonian 
  

   representative. 
  It 
  is 
  founded 
  upon 
  a 
  single 
  specimen, 
  in 
  excellent 
  

   preservation 
  as 
  to 
  some 
  details, 
  but 
  unfortunately 
  broken 
  so 
  that 
  

   both 
  the 
  distal 
  and 
  proximal 
  portions 
  are 
  wanting. 
  The 
  arrange- 
  

   ment 
  of 
  cirri 
  is 
  upon 
  the 
  plan 
  of 
  M. 
  convolutus, 
  but 
  they 
  are 
  rela- 
  

   tively 
  shorter 
  and 
  coarser. 
  The 
  most 
  striking 
  characters 
  are 
  the 
  

   robustness 
  of 
  the 
  proximal 
  neck, 
  which 
  is 
  about 
  half 
  the 
  diameter 
  of 
  

   the 
  main 
  stem 
  in 
  the 
  next 
  adjoining 
  coil, 
  and 
  the 
  peculiar 
  distribu- 
  

   tion 
  of 
  the 
  columnals 
  of 
  which 
  it 
  is 
  composed. 
  These 
  are 
  extremely 
  

   thin 
  throughout, 
  about 
  .17 
  mm. 
  on 
  the 
  outer 
  side 
  of 
  the 
  curve, 
  but 
  

   in 
  the 
  portion 
  of 
  the 
  neck 
  which 
  is 
  proximal 
  to 
  the 
  calyx, 
  they 
  seem 
  

   to 
  become 
  coalesced 
  at 
  either 
  side 
  so 
  as 
  to 
  form 
  for 
  every 
  two 
  ossicles 
  

   a 
  single 
  one 
  of 
  double 
  their 
  length. 
  Thus 
  in 
  a 
  side 
  view 
  the 
  colum- 
  

   nals 
  here 
  are 
  about 
  .35 
  mm. 
  in 
  length 
  at 
  the 
  bottom, 
  and 
  when 
  seen 
  

   from 
  the 
  top 
  one 
  of 
  the 
  ossicles 
  takes 
  on 
  a 
  lenticular 
  form. 
  At 
  some 
  

   point 
  between 
  this 
  part, 
  which 
  is 
  that 
  freely 
  exposed 
  in 
  the 
  figures, 
  

   and 
  that 
  where 
  the 
  reversed 
  curve 
  begins, 
  this 
  doubling 
  in 
  length 
  

   of 
  columnals 
  seems 
  to 
  disappear, 
  so 
  that 
  it 
  is 
  not 
  continuous 
  for 
  the 
  

   whole 
  of 
  the 
  neck. 
  The 
  ends 
  of 
  the 
  enlarged 
  columnals, 
  and 
  the 
  

   form 
  of 
  the 
  lenticular 
  ossicle 
  between 
  them, 
  have 
  nearly 
  the 
  appear- 
  

   ance 
  of 
  those 
  in 
  the 
  variet}/ 
  bijugicirrus, 
  but 
  in 
  fact 
  they 
  have 
  no 
  

   facets 
  and 
  b:ar 
  no 
  relation 
  whatever 
  to 
  cirri. 
  I 
  am 
  unable 
  to 
  give 
  

   any 
  explanation 
  of 
  this 
  singular 
  structure, 
  which 
  is 
  a 
  very 
  definite 
  

   one, 
  as 
  shown 
  by 
  the 
  detailed 
  drawings. 
  

  

  The 
  species 
  is 
  named 
  in 
  honor 
  of 
  Prof. 
  Charles 
  Schuchert, 
  by 
  

   whom 
  the 
  unique 
  type 
  was 
  collected 
  many 
  years 
  ago 
  in 
  the 
  course 
  of 
  

   researches 
  upon 
  the 
  Helderbergian 
  formations 
  of 
  Tennessee. 
  

  

  Horizon 
  and 
  locality. 
  — 
  Helderbergian, 
  Linden 
  formation 
  ; 
  Benton 
  

   county, 
  Tennessee. 
  

  

  AMMONICRINUS, 
  new 
  genus 
  

  

  Plate 
  G 
  

  

  Of 
  the 
  type 
  of 
  Myelodactylus 
  in 
  having 
  the 
  crown 
  enveloped 
  by 
  

   a 
  coiled 
  bilateral 
  stem; 
  but 
  without 
  jointed 
  cirri, 
  their 
  place 
  being 
  

   taken 
  by 
  unarticulated 
  solid 
  processes 
  projecting 
  from 
  the 
  two 
  horns 
  

   of 
  the 
  crescentic 
  columnals; 
  and 
  with 
  calyx 
  of 
  Camerate 
  type. 
  

  

  Genotype. 
  — 
  Ammonicrinus 
  wanneri, 
  new 
  species. 
  

  

  Distribution. 
  — 
  Middle 
  Devonian; 
  Eifel, 
  Germany. 
  

  

  AMMONICRINUS 
  WANNERI, 
  new 
  species 
  

  

  Plate 
  6, 
  figs. 
  4-6 
  

  

  I 
  have 
  proposed 
  this 
  genus 
  and 
  species 
  upon 
  the 
  evidence 
  of 
  two 
  

   very 
  perfect 
  specimens 
  and 
  some 
  fragments 
  from 
  the 
  Middle 
  De- 
  

  

  