﻿G. 
  M. 
  Thomson. 
  — 
  On 
  a 
  Crustacean 
  from 
  Auckland 
  Islands. 
  249 
  

  

  Art. 
  XIX. 
  — 
  -Description 
  of 
  New 
  Crustacean 
  from 
  the 
  Auckland 
  Islands. 
  

   By 
  George 
  M. 
  Thomson. 
  

  

  [Bead 
  before 
  the 
  Otago 
  Institute, 
  10th 
  September, 
  1878.] 
  

  

  Fam. 
  Oiiiscidse. 
  Suh-fam. 
  Scypliacinse. 
  

  

  Genus 
  Actfecia, 
  Dana, 
  U.S. 
  Explor. 
  Exped., 
  XIV. 
  Crust., 
  p. 
  li., 
  p. 
  734. 
  

  

  Autenuge 
  very 
  stout, 
  not 
  distinctly 
  geniculate 
  at 
  the 
  fifth 
  joint; 
  flagellum 
  

   indistinctly 
  6-6-jointed, 
  exclusive 
  of 
  the 
  minute 
  apical 
  joint. 
  Terminal 
  

   joint 
  of 
  maxillipeds 
  broad 
  and 
  serrately 
  lobed. 
  Feet 
  of 
  the 
  seventh 
  pair 
  as 
  

   long 
  as 
  the 
  others. 
  

  

  After 
  his 
  description 
  of 
  Scyphax 
  ornatus, 
  Dana 
  describes 
  and 
  figures 
  a 
  

   smaller 
  specimen 
  which 
  was 
  found 
  at 
  the 
  same 
  time 
  and 
  in 
  the 
  same 
  

   locality, 
  and 
  which 
  he 
  suspects 
  may 
  be 
  the 
  young 
  of 
  that 
  species. 
  Besides 
  

   many 
  minor 
  points 
  of 
  difference, 
  however, 
  it 
  is 
  quite 
  distinct 
  from 
  the 
  

   generic 
  character 
  of 
  Scyphax, 
  in 
  possessing 
  the 
  seventh 
  pair 
  of 
  legs 
  of 
  

   normal 
  size. 
  He 
  remarks, 
  that 
  if 
  this 
  is 
  a 
  new 
  species, 
  it 
  is 
  also 
  a 
  distinct 
  

   genus, 
  and 
  suggests 
  that 
  it 
  may 
  be 
  named 
  Actcecia 
  euchroa 
  as 
  designated 
  in 
  

   his 
  earlier 
  MSB. 
  The 
  species 
  found 
  by 
  Mr. 
  Jennings 
  on 
  the 
  Auckland 
  

   Islands, 
  being 
  evidently 
  an 
  Actcecia, 
  I 
  have 
  drawn 
  up 
  the 
  above 
  generic 
  

   character. 
  The 
  genus 
  therefore 
  contains 
  the 
  following 
  species 
  : 
  — 
  

  

  1. 
  Actcecia 
  euchroa, 
  Dana. 
  

  

  Body 
  elliptic, 
  abdomen 
  not 
  abruptly 
  narrower 
  than 
  thorax. 
  Head 
  short, 
  

   transverse. 
  Eyes 
  rather 
  large 
  and 
  prominent. 
  Antennse 
  short, 
  curving 
  

   outwards, 
  surface 
  minutely 
  spinulous. 
  Last 
  thoracic 
  segment 
  not 
  shorter 
  

   than 
  the 
  preceding. 
  Abdomen 
  filling 
  the 
  concavity 
  below 
  the 
  last 
  thoracic 
  

   segment, 
  and 
  forming 
  a 
  semicircle 
  beyond 
  it. 
  Third, 
  fourth 
  and 
  fifth 
  

   abdominal 
  segments 
  much 
  produced 
  backward 
  on 
  either 
  side. 
  Last 
  seg- 
  

   ment 
  smallest, 
  not 
  projecting 
  between 
  the 
  stylets, 
  which 
  are 
  placed 
  close 
  

   together. 
  Large 
  branch 
  of 
  stylets 
  very 
  short 
  and 
  obtuse 
  ; 
  smaller 
  branch 
  

   quite 
  slender 
  and 
  arising 
  from 
  a 
  ^Doint 
  far 
  anterior 
  to 
  the 
  base 
  of 
  the 
  larger 
  

   branch. 
  

  

  Surface 
  of 
  thorax 
  and 
  abdomen 
  with 
  a 
  few 
  very 
  short 
  scattered 
  spinules. 
  

   Length 
  2 
  lines. 
  

  

  Bay 
  of 
  Islands 
  — 
  Parua 
  Harbour 
  (Dana). 
  

  

  2. 
  Actcecia 
  aucklandicB, 
  nov. 
  sp. 
  

  

  Body 
  narrow-oblong, 
  abdomen 
  narrowing 
  gradually 
  from 
  the 
  thoral. 
  

   Head 
  triangular, 
  widest 
  in 
  front 
  ; 
  anterior 
  margin 
  nearly 
  straight, 
  rounded 
  

   at 
  the 
  corners; 
  eyes 
  situated 
  above 
  the 
  angular 
  projections. 
  Segments 
  of 
  

   thorax 
  subequal, 
  more 
  or 
  less 
  acutely 
  produced 
  posteriorly. 
  Two 
  first 
  seg- 
  

   ments 
  of 
  the 
  abdomen 
  partly 
  covered 
  by 
  thorax; 
  last 
  segment 
  (sixth) 
  much 
  

   narrower 
  than 
  preceding, 
  broadly 
  triangular, 
  and 
  with 
  obtuse 
  apex. 
  Caudal 
  

   stylets 
  subequal, 
  only 
  about 
  half 
  as 
  long 
  as 
  abdomen; 
  inner 
  rami 
  placed 
  

  

  a2 
  

  

  