﻿HO 
  Mr. 
  E. 
  W. 
  Sexton 
  on 
  

  

  LX. 
  — 
  A 
  new 
  Amphipod 
  Species, 
  Tryphosites 
  alleni. 
  By 
  

   E. 
  W. 
  SEXTONj 
  Marine 
  Biological 
  Laboratory, 
  Plymouth. 
  

  

  [Plate 
  XIV.] 
  

  

  Two 
  specimens 
  of 
  the 
  species 
  described 
  below 
  were 
  taken 
  by 
  

   Dr. 
  Allen 
  during 
  the 
  cruise 
  of 
  the 
  ' 
  Huxley' 
  in 
  the 
  north 
  of 
  

   the 
  Bay 
  of 
  Biscay, 
  August 
  1906, 
  trawled 
  in 
  246 
  fathoms, 
  

   48° 
  7' 
  N., 
  8° 
  13' 
  W. 
  

  

  Fam. 
  Lysianassidae. 
  

  

  Genus 
  Tryphosites, 
  G. 
  0. 
  Sars. 
  

  

  Tryphosites 
  alleni, 
  sp. 
  n. 
  (PI. 
  XIV.) 
  

  

  Two 
  specimens, 
  ovigerous 
  females, 
  measuring 
  10 
  mm. 
  from 
  

   the 
  tip 
  of 
  the 
  rostrum 
  to 
  the 
  tip 
  of 
  the 
  telson. 
  

  

  Besides 
  these 
  two 
  specimens 
  I 
  have 
  been 
  able, 
  through 
  

   Mr. 
  Tattersall's 
  kindness, 
  to 
  examine 
  some 
  fourteen 
  others, 
  

   taken, 
  together 
  with 
  the 
  type 
  species, 
  T. 
  longipes, 
  by 
  the 
  

   1 
  Helga 
  ' 
  on 
  the 
  west 
  of 
  Ireland, 
  in 
  200 
  fathoms. 
  They 
  were 
  

   of 
  all 
  sizes, 
  measuring 
  from 
  2"5 
  mm. 
  to 
  10 
  mm. 
  in 
  length 
  ; 
  

   the 
  four 
  largest 
  were 
  males. 
  

  

  With 
  regard 
  to 
  the 
  distribution 
  of 
  the 
  two 
  species, 
  Mr. 
  

   Tattersall 
  has 
  informed 
  me 
  that 
  " 
  T. 
  longipes 
  is 
  alone 
  found 
  

   in 
  shallow 
  water. 
  The 
  other 
  form 
  is 
  alone 
  found 
  in 
  very 
  

   deep 
  water, 
  and 
  the 
  two 
  forms 
  together 
  in 
  intermediate 
  

   depths." 
  

  

  Description. 
  

  

  In 
  general 
  aspect 
  much 
  resembling 
  the 
  type 
  species, 
  

   T. 
  longipes 
  *, 
  the 
  principal 
  distinguishing 
  characters 
  being 
  

   found 
  in 
  the 
  hand 
  of 
  gnathopod 
  2, 
  the 
  shape 
  of 
  side-plate 
  4, 
  

   the 
  epimera 
  of 
  pleon-segment 
  3, 
  and 
  the 
  telson. 
  

  

  Bead 
  longer 
  than 
  the 
  first 
  peiEeon-segment, 
  but 
  not 
  equal 
  

   to 
  the 
  first 
  two 
  in 
  length; 
  lateral 
  corners 
  much 
  produced 
  and 
  

   acute. 
  

  

  Eyes 
  large, 
  a 
  long 
  oval, 
  pigment 
  faded. 
  

  

  Side-plates 
  as 
  in 
  the 
  type 
  species 
  with 
  the 
  exception 
  of 
  

   side-plate 
  4 
  ; 
  in 
  this 
  (fig. 
  1) 
  the 
  projecting 
  portion 
  of 
  the 
  

   lower 
  hind 
  margin 
  is 
  rounded, 
  in 
  longipes 
  it 
  is 
  truncate 
  and 
  

   angular. 
  

  

  * 
  A 
  full 
  description 
  and 
  figures 
  will 
  be 
  found 
  in 
  Prof. 
  Sars's 
  ' 
  Crustacea 
  

   of 
  Norway,' 
  vol. 
  i. 
  p. 
  81, 
  pi. 
  xxviii. 
  fig 
  - 
  . 
  3, 
  and 
  pi. 
  xxix. 
  fig. 
  1. 
  

  

  