﻿Crustacea 
  of 
  Dominica. 
  13 
  

  

  Ophthahnopods 
  short, 
  cylindrical, 
  not 
  narrowed 
  at 
  the 
  base, 
  

   separated 
  from 
  each 
  other 
  below 
  by 
  a 
  small 
  vertical 
  plate. 
  

  

  Antennula. 
  — 
  Basal 
  segment 
  of 
  peduncle 
  more 
  or 
  less 
  hairy, 
  

   hollowed 
  above 
  at 
  its 
  proximal 
  end, 
  furnished 
  externally 
  with 
  

   a 
  large 
  tooth 
  which 
  does 
  not 
  reach 
  so 
  far 
  as 
  its 
  anterior 
  mar- 
  

   gin 
  ; 
  anterior 
  margin 
  armed 
  with 
  a 
  series 
  of 
  strong 
  spines 
  

   interspersed 
  with 
  hairs 
  ; 
  inferior 
  surface 
  flat, 
  its 
  inner 
  edge 
  

   forming 
  a 
  ridge, 
  which 
  terminates 
  in 
  front 
  in 
  a 
  small 
  tooth. 
  

   Second 
  segment 
  about 
  equal 
  in 
  length 
  to 
  the 
  first, 
  armed 
  

   above 
  with 
  more 
  or 
  fewer 
  small 
  scattered 
  spines 
  and 
  in 
  front 
  

   with 
  a 
  marginal 
  series 
  of 
  spines 
  interspersed 
  with 
  hairs 
  ; 
  

   outer, 
  inner, 
  and 
  under 
  surfaces 
  smooth, 
  except 
  for 
  a 
  series 
  of 
  

   hairs 
  along 
  the 
  inner 
  inferior 
  edge. 
  Third 
  segment 
  the 
  

   shortest, 
  armed 
  above 
  like 
  the 
  second 
  with 
  scattered 
  spines 
  

   and 
  a 
  marginal 
  series, 
  its 
  inferior 
  edge 
  furnished 
  with 
  hairs, 
  

   which 
  are 
  conspicuously 
  long 
  in 
  front. 
  The 
  superior 
  spines 
  

   .on 
  the 
  two 
  segments 
  which 
  have 
  been 
  just 
  described 
  may 
  in 
  

   small 
  specimens 
  be 
  wholly 
  absent. 
  The 
  inner 
  Jlagellum 
  

   longer 
  than 
  the 
  outer, 
  slightly 
  longer 
  than 
  the 
  carapace, 
  the 
  

   outer 
  slightly 
  shorter. 
  

  

  Antenna. 
  — 
  Distal 
  segment 
  of 
  peduncle 
  cylindrical, 
  not 
  

   projecting 
  quite 
  so 
  far 
  forwards 
  as 
  the 
  peduncle 
  of 
  the 
  an- 
  

   tennula, 
  with 
  a 
  marginal 
  series 
  of 
  hairs 
  and 
  small 
  spines 
  on 
  

   its 
  inner 
  surface 
  ; 
  externally 
  beneath 
  the 
  scale 
  there 
  is 
  a 
  

   pointed 
  process 
  which 
  projects 
  about 
  as 
  far 
  as 
  the 
  apex 
  of 
  the 
  

   antennular 
  spine. 
  Scale 
  with 
  parallel 
  edges, 
  ovate 
  in 
  front, 
  

   fringed 
  on 
  the 
  inner 
  edge 
  and 
  on 
  the 
  outer 
  edge 
  distally 
  with 
  

   long 
  hairs, 
  projecting 
  beyond 
  the 
  antennular 
  peduncle, 
  bearing 
  

   a 
  small 
  spine 
  on 
  the 
  outer 
  side. 
  Flagellum 
  when 
  stretched 
  

   backwards 
  reaching 
  about 
  as 
  far 
  as 
  the 
  end 
  of 
  the 
  body. 
  

  

  Pereiopods. 
  — 
  First 
  and 
  second 
  pairs 
  almost 
  alike 
  in 
  form 
  

   and 
  size. 
  Ischium 
  running 
  considerably 
  forwards 
  beneath 
  

   the 
  proximal 
  half 
  of 
  the 
  merus 
  and 
  with 
  it 
  constituting 
  almost 
  

   one 
  segment 
  ; 
  merus 
  furnished 
  externally 
  above 
  with 
  a 
  con- 
  

   spicuous, 
  long, 
  smooth 
  sulcus 
  ; 
  this 
  ischio-meral 
  segment 
  

   externally 
  hairy 
  or 
  smooth 
  and 
  in 
  the 
  larger 
  specimens 
  

   tubercular, 
  the 
  second 
  pereiopod 
  being 
  more 
  tubercular 
  than 
  

   the 
  first 
  ; 
  carpus, 
  propodus, 
  and 
  dactylus 
  also 
  slightly 
  tuber- 
  

   cular 
  or 
  smooth 
  ; 
  propodus 
  and 
  dactylus 
  terminated 
  with 
  long- 
  

   tufts 
  of 
  hairs. 
  Third 
  pereiopod 
  the 
  largest, 
  the 
  ischio-meral 
  

   segment 
  longer 
  than 
  the 
  three 
  segments 
  which 
  succeed 
  it 
  

   taken 
  together, 
  flatter 
  on 
  the 
  inner 
  surface, 
  rounded 
  externally 
  

   from 
  above 
  downwards. 
  In 
  the 
  largest 
  specimens 
  covered 
  

   externally 
  more 
  or 
  less 
  thickly 
  with 
  rounded 
  or 
  conical 
  smooth 
  

   tubercles, 
  exhibiting 
  a 
  tendency 
  to 
  arrangement 
  in 
  longitu- 
  

   dinal 
  series 
  ; 
  the 
  inner 
  surface 
  is 
  much 
  more 
  scantily 
  beset 
  

  

  