﻿[81] 
  

  

  DECAPODA 
  FROM 
  ALBATROSS 
  DREDGINGS. 
  

  

  685 
  

  

  epipods 
  ; 
  there 
  is 
  a 
  well-developed 
  pleurobranchia 
  on 
  the 
  fourteenth 
  

   somite. 
  The 
  number 
  and 
  arrangement 
  of 
  the 
  branchiae 
  and 
  epipods 
  are 
  

   the 
  same 
  for 
  all 
  these 
  species, 
  and 
  as 
  indicated 
  in 
  the 
  following 
  formula: 
  

  

  Parapen^us 
  Smith. 
  

  

  The 
  species 
  referred 
  to 
  this 
  genus 
  are 
  at 
  once 
  distinguished 
  from 
  the 
  

   species 
  of 
  Penceus 
  proper 
  in 
  having 
  the 
  endognath 
  of 
  the 
  first 
  maxilla 
  

   short 
  and 
  unsegmented, 
  the 
  second 
  gnathopod 
  without 
  an 
  epipod, 
  and 
  

   the 
  fourteenth 
  somite 
  (posterior 
  somite 
  of 
  the 
  peraeon) 
  wholly 
  without 
  

   branchiae. 
  The 
  species 
  examined 
  further 
  agree 
  in 
  having 
  none 
  of 
  the 
  

   sulci 
  of 
  the 
  carapax 
  conspicuous 
  except 
  the 
  cervical, 
  and 
  in 
  having 
  the 
  

   antennular 
  flagella 
  shorter 
  than 
  the 
  carapax. 
  In 
  Parapenccus 
  longirostris, 
  

   politus, 
  and 
  megalops, 
  the 
  mandibular 
  palpi 
  are 
  as 
  in 
  the 
  typical 
  species 
  

   of 
  Pcnwus, 
  there 
  are 
  no 
  exopods 
  at 
  the 
  bases 
  of 
  any 
  of 
  the 
  perajopods, 
  

   and 
  the 
  branchio-epipodal 
  formula 
  is 
  as 
  follows: 
  

  

  While 
  in 
  Parapenceus 
  constrictus 
  and 
  some 
  other 
  species 
  the 
  distal 
  

   segment 
  of 
  the 
  mandibular 
  palpus 
  is 
  slightly 
  elongated 
  and 
  narrowed 
  

   distally, 
  there 
  are 
  very 
  small 
  narrow 
  lamellar 
  exopods 
  at 
  the 
  bases 
  of 
  

   all 
  the 
  peraeopods, 
  there 
  is 
  no 
  pleurobranchia 
  on 
  the 
  thirteenth 
  somite, 
  

   and 
  the 
  branchio-epipodal 
  formula 
  is 
  as 
  follows 
  : 
  

  

  These 
  characters 
  are, 
  however, 
  combined 
  to 
  a 
  certain 
  extent 
  in 
  two 
  

   other 
  species 
  which 
  I 
  have 
  examined 
  : 
  A 
  Japanese 
  species, 
  which 
  closely 
  

   resembles 
  the 
  constrictus 
  in 
  general 
  appearance, 
  but 
  has 
  no 
  exoi>ods 
  at 
  

   the 
  bases 
  of 
  the 
  posterior 
  peraeopods 
  and 
  has 
  the 
  epipods 
  and 
  branchiae 
  

  

  