﻿250 
  Transactions. 
  — 
  Zoology. 
  

  

  close 
  together 
  between 
  the 
  two 
  external, 
  completely 
  exposed. 
  Antennae 
  

   hirsute 
  ' 
  towards 
  the 
  extremity; 
  basal 
  joint- 
  short; 
  fifth 
  joint 
  expanding 
  

   posteriorly; 
  flagellum 
  short 
  and 
  thick, 
  all 
  the 
  joints 
  together 
  not 
  so 
  long 
  as 
  

   preceding. 
  Colour 
  brown. 
  Whole 
  body 
  more 
  or 
  less 
  covered 
  with 
  minute 
  

   granules. 
  

  

  In 
  the 
  female 
  each 
  segment 
  of 
  the 
  body 
  is 
  furnished 
  with 
  a 
  row 
  of 
  stout, 
  

   obtuse 
  spines, 
  which 
  are 
  longest 
  towards 
  the 
  side 
  of 
  the 
  thorax. 
  In 
  the 
  

   male 
  the 
  whole 
  body 
  is 
  nearly 
  smooth. 
  Length 
  -8 
  to 
  1-2 
  mch. 
  

  

  Auckland 
  Islands 
  (Mr. 
  Jennings). 
  

  

  Art. 
  XX. 
  — 
  Description 
  of 
  a 
  New 
  Species 
  of 
  Isopodous 
  Crustacean 
  (Idotea). 
  

   By 
  George 
  M. 
  Thomson. 
  

   (Read 
  before 
  the 
  Otago 
  Institute, 
  2&th 
  Novemler, 
  1878.) 
  

   The 
  animals 
  forming 
  the 
  genus 
  Idotea 
  are 
  readily 
  distinguished 
  from 
  other 
  

   Isopods 
  by 
  having 
  the 
  segments 
  of 
  the 
  abdomen 
  more 
  or 
  less 
  coalescent, 
  

   and 
  fewer 
  than 
  the 
  normal 
  number, 
  seven, 
  and 
  particularly 
  in 
  having 
  the 
  

   "terminal 
  segment 
  very 
  large, 
  its 
  appendages 
  greatly 
  developed, 
  covering 
  

   the 
  whole 
  inferior 
  surface 
  of 
  the 
  abdomen, 
  and 
  closing 
  like 
  doors 
  over 
  the 
  

   branchial 
  appendages." 
  

  

  Of 
  the 
  three 
  species 
  described 
  in 
  Miers' 
  Catalogue 
  of 
  N. 
  Z. 
  Crust., 
  

   pp. 
  92, 
  93, 
  the 
  first, 
  I. 
  argentea, 
  Dana, 
  is 
  a 
  doubtful 
  New 
  Zealand 
  species, 
  

   having 
  been 
  obtained 
  by 
  Dana 
  near 
  New 
  Zealand. 
  It 
  is 
  found 
  on 
  the 
  

   Australian 
  Coasts, 
  and 
  also 
  at 
  Borneo, 
  and 
  is 
  probably 
  common 
  in 
  the 
  West 
  

   Pacific. 
  The 
  second 
  species 
  I. 
  affinis, 
  M. 
  Edw., 
  is 
  common 
  on 
  our 
  coasts, 
  

   and 
  seems 
  to 
  be 
  the 
  same 
  as 
  a 
  species 
  found 
  on 
  St. 
  Paul's 
  Island, 
  and 
  at 
  the 
  

   Cape. 
  The 
  third, 
  I. 
  elongata, 
  Miers, 
  has 
  only 
  been 
  found 
  hitherto 
  at 
  the 
  

   Auckland 
  Islands. 
  The 
  species 
  which 
  I 
  now 
  propose 
  to 
  add, 
  is 
  chiefly 
  

   remarkable 
  for 
  its 
  habitat, 
  being 
  the 
  only 
  species, 
  as 
  far 
  as 
  I 
  can 
  find 
  out, 
  

   occurring 
  in 
  fresh 
  water. 
  Numerous 
  specimens 
  were 
  found 
  by 
  Prof. 
  Hutton 
  

   in 
  the 
  Tomahawk 
  lagoon, 
  near 
  Dunedin. 
  They 
  were 
  creeping 
  about 
  under 
  

   stones, 
  and 
  appeared 
  to 
  be 
  feeding 
  on 
  the 
  ova 
  of 
  a 
  fish, 
  probably 
  Galaxias, 
  

   sp., 
  which 
  was 
  found 
  abundantly 
  in 
  the 
  same 
  locality. 
  Whether 
  they 
  occur 
  

   permanently 
  in 
  the 
  fresh 
  water, 
  or 
  only 
  come 
  up 
  when 
  a 
  very 
  high 
  tide 
  

   renders 
  communication 
  with 
  the 
  lagoon 
  possible, 
  I 
  cannot 
  say. 
  The 
  species 
  

   is 
  a 
  distinct 
  one, 
  and 
  has 
  not 
  hitherto 
  been 
  found 
  on 
  our 
  coasts. 
  

  

  