﻿242 
  Transactions. 
  — 
  Zoology. 
  

  

  fringe 
  of 
  hairs 
  ou 
  the 
  lower 
  surface. 
  First 
  pair 
  of 
  gnathopoda 
  with 
  carpus 
  

   and 
  propodos 
  subequal, 
  straight, 
  and 
  densely 
  clothed 
  with 
  long, 
  feathery 
  

   hairs. 
  Second 
  pair 
  with 
  the 
  carpus 
  long, 
  straight, 
  and 
  flat 
  on 
  the 
  under 
  

   surface, 
  which 
  is 
  fringed 
  with 
  a 
  double 
  row 
  of 
  similar 
  plumose 
  hairs 
  ; 
  

   propodos 
  tapering 
  and 
  hairy 
  ; 
  dactylos 
  minute. 
  Fourth 
  and 
  fifth 
  pairs 
  of 
  

   pereiopoda 
  longer 
  and 
  stouter 
  than 
  preceding 
  pairs. 
  Antepenultimate 
  and 
  

   penultimate 
  pairs 
  of 
  pleopoda 
  reaching 
  to 
  extremity 
  of 
  ultimate 
  ; 
  all 
  three 
  

   pairs 
  fringed 
  with 
  short 
  spines. 
  Telson 
  short, 
  reaching 
  to 
  extremity 
  of 
  

   peduncle 
  of 
  ultimate 
  pleopoda, 
  and 
  furnished 
  with 
  a 
  few 
  short 
  spines. 
  

  

  (No 
  locality). 
  Length 
  -3 
  inch. 
  

  

  Sub-tribe. 
  Hyperidea. 
  

   Fam. 
  I. 
  Hyperidae, 
  Spence 
  Bate, 
  Brit. 
  Mus. 
  Cat. 
  Amphip. 
  Crust, 
  p. 
  287. 
  

  

  Superior 
  antennae, 
  with 
  a 
  peduncle 
  of 
  three 
  joints, 
  and 
  a 
  variable 
  

   flagellum. 
  Inferior 
  antennse, 
  with 
  a 
  five-jointed 
  (?) 
  peduncle, 
  and 
  multi- 
  

   articulate 
  flagellum. 
  Gnathopoda 
  more 
  or 
  less 
  complexly 
  subchelate. 
  

   Four 
  anterior 
  pairs 
  of 
  pereiojDoda 
  subequal, 
  normal. 
  Three 
  anterior 
  pairs 
  

   of 
  pleopoda 
  normal 
  ; 
  three 
  posterior 
  pairs, 
  broad, 
  flat, 
  and 
  biramous. 
  

   Integument 
  thin 
  and 
  free 
  from 
  hairs. 
  

  

  Genus 
  Themisto, 
  Guerin-Meneville, 
  Mem. 
  de 
  la 
  Soc. 
  d'Hist. 
  Nat. 
  

  

  de 
  Paris, 
  iv., 
  1828; 
  Edwards, 
  Hist, 
  des 
  Crust., 
  iii., 
  p. 
  84; 
  Spence 
  

  

  Bate, 
  Brit. 
  Mus. 
  Cat. 
  Amphip. 
  Crust, 
  p. 
  311, 
  

  

  Cephalon 
  transversely 
  ovate. 
  Pereion 
  not 
  largely 
  distended. 
  Pleon 
  

   slender. 
  Eyes 
  occupying 
  the 
  entke 
  cephalon, 
  dorsally 
  separated. 
  An- 
  

   tenna 
  subequal, 
  as 
  long 
  as 
  the 
  cephalon 
  is 
  deep 
  ; 
  superior 
  pair 
  having 
  the 
  

   flagellum 
  not 
  articulated 
  ; 
  inferior 
  pair 
  having 
  the 
  flagellum 
  more 
  or 
  less 
  

   articulated. 
  Mandible 
  having 
  an 
  appendage. 
  First 
  pan* 
  of 
  gnathopoda 
  

   short, 
  tolerably 
  robust 
  ; 
  carpus 
  not 
  having 
  the 
  anterior 
  margin 
  inferiorly 
  

   produced 
  ; 
  second 
  pair 
  having 
  the 
  carpus 
  on 
  the 
  inferior 
  angle 
  anteriorly 
  

   produced. 
  First 
  pair 
  of 
  pereiopoda 
  having 
  the 
  carpus 
  dilated 
  ; 
  propodos 
  

   narrow, 
  and 
  capable 
  of 
  being 
  inflected 
  against 
  the 
  carpus 
  ; 
  second 
  pair 
  like 
  

   the 
  first 
  ; 
  third 
  pair 
  twice 
  the 
  length 
  of 
  the 
  second 
  ; 
  carpus 
  very 
  long 
  ; 
  

   propodos 
  longer 
  than 
  the 
  carpus, 
  fringed 
  along 
  the 
  anterior 
  margin 
  with 
  a 
  

   comb-like 
  series 
  of 
  teeth, 
  and 
  capable 
  of 
  impinging 
  against 
  the 
  anterior 
  

   margin 
  of 
  the 
  carpus 
  ; 
  fourth 
  and 
  fifth 
  pairs 
  subequal, 
  of 
  the 
  same 
  form 
  as 
  

   the 
  third, 
  but 
  not 
  more 
  than 
  half 
  the 
  length. 
  Three 
  posterior 
  paks 
  of 
  

   pleopoda 
  subequal, 
  the 
  last 
  being 
  the 
  longest 
  ; 
  rami 
  double, 
  lanceolate. 
  

   Telson 
  small, 
  squamose. 
  -»_ 
  

  

  The 
  above 
  description 
  is 
  taken 
  from 
  Spence 
  Bate's 
  catalogue, 
  and 
  from 
  

   the 
  examination 
  of 
  a 
  great 
  number 
  of 
  specimens 
  I 
  can 
  vouch 
  for 
  its 
  cor- 
  

   rectness 
  as 
  far 
  as 
  females 
  are 
  concerned, 
  from 
  which 
  indeed 
  all 
  the 
  descrip- 
  

   tions 
  appear 
  to 
  have 
  been 
  taken. 
  The 
  males, 
  however, 
  differ 
  in 
  the 
  

  

  