﻿614 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  [10] 
  

  

  shade 
  of 
  red 
  or 
  orange, 
  and 
  I 
  have 
  seen 
  no 
  evidence 
  of 
  any 
  other 
  bright 
  

   color. 
  A 
  few 
  species 
  from 
  between 
  100 
  and 
  300 
  fathoms 
  are 
  conspicu- 
  

   ously 
  marked 
  with 
  scarlet 
  or 
  vermilion, 
  but 
  such 
  bright 
  markings 
  were 
  

   not 
  noticed 
  in 
  any 
  species 
  from 
  below 
  1,000 
  fathoms. 
  Below 
  this 
  depth, 
  

   orange 
  red 
  of 
  varying 
  intensity 
  is 
  apparently 
  the 
  most 
  common 
  color, 
  

   although 
  in 
  several 
  species, 
  very 
  notably 
  in 
  Notostomus 
  robustus, 
  the 
  

   color 
  is 
  an 
  exceedingly 
  intense 
  dark 
  crimson. 
  

  

  The 
  structure 
  of 
  the 
  eyes 
  of 
  the 
  abyssal 
  Decapoda 
  is 
  of 
  the 
  highest 
  in- 
  

   terest, 
  and 
  worthy 
  of 
  the 
  most 
  minute 
  and 
  careful 
  investigation 
  and 
  

   comparison 
  with 
  the 
  corresponding 
  structures 
  of 
  the 
  shallow-water 
  and 
  

   surface 
  forms. 
  Such 
  an 
  investigation 
  I 
  have 
  not 
  been 
  able 
  thus 
  far 
  to 
  

   make, 
  but 
  the 
  importance 
  of 
  the 
  subject 
  induces 
  me 
  to 
  record 
  the 
  re- 
  

   sults 
  of 
  a 
  superficial 
  examination 
  of 
  the 
  external 
  characters 
  of 
  the 
  eyes 
  

   of 
  most 
  of 
  the 
  abyssal 
  species 
  from 
  the 
  Albatross 
  collections. 
  These 
  

   imperfect 
  observations 
  have 
  been 
  briefly 
  given 
  under 
  each 
  species 
  iu 
  

   the 
  list 
  of 
  species 
  taken 
  below 
  1,000 
  fathoms. 
  

  

  If 
  we 
  exclude 
  from 
  this 
  list 
  all 
  the 
  species 
  whose 
  bathymetrical 
  habi- 
  

   tats 
  are 
  in 
  any 
  degree 
  doubtful, 
  and 
  examine 
  the 
  21 
  species 
  given 
  as 
  

   inhabiting 
  the 
  immediate 
  neighborhood 
  of 
  the 
  bottom, 
  we 
  find 
  that 
  

   Geryon 
  quinqucdens, 
  Lithodes 
  Agassizii, 
  and 
  Sabinea 
  princeps 
  have 
  nor- 
  

   mal, 
  well-developed 
  large 
  black 
  eyes 
  apparently 
  entirely 
  similar 
  to 
  

   those 
  of 
  allied 
  shallow-water 
  species. 
  Sclerocrangon 
  Agassizii, 
  Bythoca- 
  

   ris 
  gracilis, 
  Heterocarpus 
  oryx, 
  Nematocarcinus 
  erisiferus, 
  and 
  jV 
  7 
  . 
  cursor 
  

   have 
  normal 
  black 
  eyes 
  apparently 
  a 
  little 
  smaller 
  than 
  those 
  of 
  the 
  

   allied 
  shallow-water 
  species. 
  Ethusina 
  abyssicola 
  and 
  Parapagurus 
  

   pilosimanus 
  have 
  distinctly 
  faceted 
  black 
  eyes, 
  which, 
  though 
  very 
  

   much 
  smaller 
  than 
  inmost 
  shallow-water 
  species, 
  are 
  still 
  fully 
  as 
  large 
  

   aud 
  apparently 
  quite 
  as 
  perfect 
  as 
  in 
  those 
  of 
  some 
  shallow-water 
  

   species 
  iu 
  which 
  they 
  are 
  evidently 
  sensitive 
  to 
  ordinary 
  changes 
  of 
  

   light. 
  The 
  eyes 
  of 
  the 
  species 
  of 
  Glyphocrangon 
  are 
  very 
  large, 
  with 
  the 
  

   faceted 
  surface 
  much 
  larger 
  than 
  the 
  allied 
  shallow-water 
  species, 
  but 
  

   they 
  are 
  borne 
  on 
  very 
  short 
  stalks 
  with 
  comparatively 
  little 
  mobility, 
  

   aud 
  have 
  dark 
  purple 
  instead 
  of 
  black 
  pigment. 
  The 
  eyes 
  of 
  Pontoph 
  Hits 
  

   abyssi 
  are 
  lighter 
  in 
  color 
  than 
  those 
  of 
  the 
  species 
  of 
  Glyphocrangon, 
  

   but 
  are 
  faceted 
  and 
  apparently 
  have 
  some 
  of 
  the 
  normal 
  visual 
  elements. 
  

   All 
  the 
  species 
  of 
  Munidopsis 
  and 
  of 
  Pentaehclcs 
  have 
  peculiarly 
  modified 
  

   eyes 
  from 
  which 
  the 
  normal 
  visual 
  elements 
  are 
  apparently 
  wanting. 
  

   Of 
  these 
  21 
  abyssal 
  species, 
  7 
  are 
  thus 
  seen 
  to 
  have 
  normal 
  black 
  eyes, 
  

   2 
  have 
  abnormally 
  small 
  eyes, 
  and 
  3 
  have 
  large 
  eyes 
  with 
  purplish 
  or 
  

   very 
  light 
  colored 
  pigment, 
  while 
  8 
  have 
  eyes 
  of 
  perhaps 
  doubtful 
  func- 
  

   tion. 
  If 
  we 
  confine 
  this 
  examination 
  to 
  the 
  5 
  species 
  taken 
  below 
  2,000 
  

   fathoms, 
  we 
  have 
  1 
  species 
  with 
  well-developed 
  black 
  eyes, 
  2 
  with 
  ab- 
  

   normally 
  small 
  black 
  eyes, 
  1 
  with 
  light 
  colored 
  eyes, 
  and 
  1 
  with 
  eyes 
  of 
  

   doubtful 
  function. 
  

  

  These 
  facts 
  and 
  the 
  comparison 
  of 
  the 
  eyes 
  and 
  the 
  color 
  of 
  the 
  abys- 
  

   sal 
  species 
  with 
  the 
  blind 
  and 
  colorless 
  cave-dwelling 
  crustaceans 
  cer- 
  

  

  