﻿512 
  COLLECTIONS 
  FROM 
  THE 
  WESTERN 
  INDIAN 
  OCEAN. 
  

  

  Neoplax 
  ophiodes. 
  (Plate 
  XLV. 
  figs, 
  a-e.) 
  

  

  Disk 
  pentagonal 
  and 
  small 
  ; 
  arms 
  narrow, 
  elongated, 
  having 
  tlio 
  

   general 
  appearance 
  of 
  being 
  somewhat 
  constricted 
  between 
  each 
  

   joint, 
  owing, 
  probably, 
  to 
  the 
  mode 
  of 
  attachment 
  of 
  the 
  spines 
  to 
  

   the 
  edge 
  of 
  the 
  side 
  arm-plates. 
  Granules 
  on 
  the 
  disk 
  rather 
  large, 
  

   sparse, 
  scattered, 
  sometimes 
  almost 
  glassy 
  in 
  appearance 
  ; 
  at 
  the 
  edge 
  

   of 
  the 
  disk 
  thej- 
  are 
  more 
  closely 
  packed 
  and 
  form 
  a 
  pretty 
  definite 
  row 
  

   of 
  bounding 
  granules. 
  Very 
  few 
  granules 
  on 
  the 
  actinal 
  surface. 
  

  

  Mouth-plates 
  oval, 
  a 
  good 
  deal 
  broader 
  than 
  long, 
  the 
  side 
  mouth- 
  

   shields 
  lying 
  across 
  them, 
  so 
  as 
  almost, 
  or 
  altogether, 
  to 
  meet 
  in 
  the 
  

   middle 
  line. 
  Five 
  mouth-papillce, 
  four 
  close 
  together, 
  the 
  fifth 
  

   close 
  to 
  its 
  fellow 
  of 
  tho 
  opposite 
  sidel 
  Three 
  or 
  four 
  pretty 
  strong 
  

   teeth. 
  

  

  Though 
  the 
  genital 
  slits 
  are 
  ordinarily 
  long, 
  the 
  bridge 
  separating 
  

   the 
  fellows 
  of 
  a 
  pair 
  is 
  of 
  a 
  fair 
  breadth 
  ; 
  genital 
  scale 
  prominent. 
  

  

  On 
  the 
  fourth 
  or 
  fifth 
  joint 
  from 
  the 
  disk 
  there 
  are 
  six 
  small 
  

   but 
  distinct 
  lateral 
  spines, 
  attached 
  to 
  the 
  edge 
  of 
  the 
  lateral 
  plate 
  ; 
  

   and 
  further 
  out 
  there 
  may 
  be 
  seven 
  spines. 
  The 
  lowest 
  spine 
  is 
  

   the 
  longest 
  and 
  the 
  most 
  distinct. 
  The 
  upper 
  arm-plates 
  are 
  widest 
  

   along 
  their 
  proximal 
  edge, 
  the 
  sides 
  slope 
  inwards, 
  and 
  the 
  distal 
  

   edge 
  is 
  much 
  narrower. 
  The 
  most 
  distinctive 
  character 
  in 
  the 
  

   lower 
  arm-plates 
  appears 
  to 
  be 
  the 
  excavation 
  on 
  the 
  distal 
  edge. 
  

   The 
  tentacle-scale 
  is 
  single, 
  small, 
  and 
  at 
  times, 
  indeed, 
  appears 
  to 
  

   be 
  absent. 
  

  

  Diam. 
  of 
  disk 
  11-5, 
  8. 
  Length 
  of 
  arm 
  (probable), 
  60, 
  40 
  millim. 
  

  

  Coloration 
  : 
  the 
  three 
  specimens 
  exhibit 
  some 
  ditferences, 
  but 
  are 
  

   all 
  brownish 
  above 
  and 
  of 
  a 
  lighter 
  hue 
  below 
  ; 
  several 
  arm 
  -joints 
  

   are, 
  here 
  and 
  there, 
  darker 
  than 
  those 
  just 
  in 
  front 
  of 
  or 
  behind 
  

   them. 
  

  

  All 
  the 
  three 
  specimens 
  were 
  found 
  at 
  Darros 
  Island, 
  Amirante 
  

   group, 
  at 
  a 
  depth 
  of 
  22 
  fms. 
  

  

  