﻿48 
  Dr. 
  H. 
  Ludwig 
  on 
  Ophiopteron 
  elegans. 
  

  

  minute, 
  circular, 
  latticed 
  plates, 
  in 
  the 
  middle 
  of 
  which 
  rises 
  

   a 
  short 
  spinule, 
  which 
  bears 
  at 
  its 
  free 
  extremity 
  several 
  

   parallel 
  points 
  but 
  no 
  funnel. 
  

  

  The 
  peristome 
  is 
  3 
  millim. 
  in 
  diameter 
  and 
  is 
  constructed 
  

   in 
  a 
  manner 
  which 
  at 
  once 
  reminds 
  one 
  of 
  the 
  genera 
  Ophio- 
  

   thrix 
  and 
  Ophiogymna. 
  Buccal 
  papillae 
  are 
  entirely 
  wanting. 
  

   The 
  dental 
  papillae 
  stand 
  externally 
  in 
  three, 
  and 
  further 
  

   inwards 
  in 
  two 
  rows 
  one 
  over 
  the 
  other 
  ; 
  whether 
  these 
  are 
  

   followed 
  further 
  in 
  by 
  some 
  true 
  teeth 
  (i. 
  e. 
  papilla? 
  standing 
  

   in 
  a 
  row 
  one 
  above 
  the 
  other) 
  I 
  could 
  not 
  ascertain 
  without 
  

   damaging 
  the 
  specimen 
  too 
  much. 
  The 
  corner-pieces 
  of 
  the 
  

   mouth 
  leave 
  between 
  them 
  a 
  gap 
  widening 
  aborally 
  in 
  the 
  

   middle 
  line 
  of 
  each 
  interradius. 
  The 
  lateral 
  buccal 
  scutes 
  

   are 
  slightly 
  curved, 
  narrow, 
  broader 
  at 
  the 
  adradial 
  than 
  at 
  

   the 
  abradial 
  end, 
  and 
  do 
  not 
  touch 
  each 
  other. 
  The 
  buccal 
  

   scutes 
  are 
  broader 
  than 
  long, 
  rhomboidal, 
  with 
  rounded 
  

   angles 
  and 
  slightly 
  emarginate 
  sides; 
  the 
  aboral 
  angle 
  is 
  

   much 
  more 
  broadly 
  rounded 
  off 
  than 
  the 
  adoral. 
  The 
  broad 
  

   buccal 
  fissures 
  are 
  directly 
  contiguous 
  to 
  the 
  outer 
  sides 
  of 
  

   the 
  buccal 
  scutes, 
  and 
  are 
  separated 
  only 
  by 
  a 
  narrow 
  inter- 
  

   space 
  at 
  the 
  outer 
  angles 
  of 
  the 
  latter 
  *. 
  

  

  Systematic 
  Position. 
  — 
  The 
  above-described 
  fins 
  are 
  per- 
  

   fectly 
  characteristic 
  of 
  the 
  present 
  form, 
  and 
  as 
  we 
  know 
  of 
  

   no 
  similar 
  arrangement 
  in 
  any 
  other 
  species 
  of 
  Ophiurid, 
  it 
  

   seems 
  justifiable 
  to 
  establish 
  a 
  new 
  genus 
  under 
  the 
  name 
  of 
  

   Ophiopteron. 
  But 
  if 
  we 
  leave 
  the 
  fins 
  out 
  of 
  consideration, 
  

   and 
  only 
  look 
  at 
  the 
  other 
  characters, 
  our 
  new 
  form 
  appears 
  

   to 
  be 
  most 
  nearly 
  related 
  to 
  the 
  genus 
  OpMoihrix. 
  In 
  favour 
  

   of 
  this 
  relationship 
  we 
  have 
  not 
  only 
  the 
  structure 
  of 
  the 
  

   peristome, 
  but 
  also 
  the 
  rest 
  of 
  the 
  formation 
  of 
  the 
  disk, 
  as 
  

   well 
  as, 
  in 
  an 
  equal 
  degree, 
  the 
  structure 
  of 
  the 
  arms. 
  The 
  

   peristome 
  of 
  Ophiopteron 
  presents 
  the 
  same 
  characters 
  as 
  in 
  

   Ophiothrix 
  — 
  the 
  absence 
  of 
  buccal 
  papillae, 
  gaps 
  between 
  

   the 
  buccal 
  corner-pieces, 
  and 
  transverse 
  buccal 
  scutes 
  not 
  

   projecting 
  into 
  the 
  interbrachial 
  regions. 
  The 
  radial 
  scutes 
  

   also 
  agree 
  in 
  form 
  and 
  position 
  with 
  those 
  of 
  Ophiothrix. 
  

   The 
  peculiar 
  funnel-shaped 
  spinosity 
  of 
  the 
  back 
  of 
  the 
  disk, 
  

   so 
  far 
  as 
  it 
  consists 
  of 
  calcareous 
  tissue, 
  is 
  present 
  in 
  several 
  

   species 
  of 
  Ophiothrix 
  ; 
  but 
  the 
  latter 
  do 
  not 
  possess 
  the 
  fine 
  

  

  * 
  After 
  the 
  above 
  description 
  was 
  written 
  I 
  received 
  from 
  Dr. 
  Brock 
  

   a 
  second, 
  but 
  unfortunately 
  very 
  badly 
  preserved 
  specimen, 
  the 
  arms 
  of 
  

   which 
  are 
  as 
  much 
  as 
  36 
  millim. 
  long, 
  while 
  the 
  disk 
  has 
  the 
  same 
  diameter 
  

   as 
  in 
  the 
  specimen 
  above 
  described. 
  In 
  this 
  second 
  example 
  the 
  colour 
  

   of 
  the 
  disk 
  is 
  light 
  greenish 
  and 
  the 
  arms 
  show 
  indications 
  of 
  pale 
  green 
  

   transverse 
  bands. 
  It 
  is 
  particularly 
  remarkable 
  that 
  the 
  fins 
  are 
  so 
  torn 
  

   and 
  damaged 
  that 
  at 
  the 
  first 
  glance 
  one 
  can 
  hardly 
  recognize 
  the 
  animal. 
  

  

  