﻿NO. 
  1136. 
  OBSERVATIONS 
  OX 
  THE 
  ASTACIDJH— 
  FAXON. 
  679 
  

  

  scale; 
  the 
  areola, 
  or, 
  in 
  other 
  words, 
  the 
  posterior 
  section 
  of 
  the 
  carapace, 
  

   is 
  much 
  longer, 
  being 
  nearly 
  one-half 
  as 
  long 
  as 
  a 
  line 
  drawn 
  from 
  the 
  

   cervical 
  groove 
  to 
  the 
  anterior 
  end 
  of 
  the 
  rostrum 
  ; 
  the 
  hand, 
  too, 
  is 
  

   provided 
  with 
  shorter 
  lingers 
  and 
  the 
  lower 
  half 
  of 
  the 
  hand 
  is 
  more 
  

   heavily 
  tuberculate 
  both 
  on 
  the 
  inner 
  and 
  outer 
  faces. 
  The 
  number 
  of 
  

   lateral 
  rostral 
  spines 
  varies 
  from 
  three 
  to 
  five 
  on 
  each 
  side; 
  the 
  number 
  

   of 
  inferior 
  spines 
  ou 
  the 
  rostrum 
  is 
  one 
  or 
  two. 
  In 
  large 
  specimens 
  

   from 
  Eoto-Iti 
  and 
  Napier 
  the 
  sides 
  of 
  the 
  carapace 
  are 
  thickly 
  set 
  wath 
  

   blunt 
  tubercles 
  which 
  become 
  spiny 
  only 
  on 
  the 
  hepatic 
  and 
  pterygo- 
  

   stomian 
  regions, 
  and 
  along 
  the 
  cervical 
  suture; 
  but 
  in 
  similarly 
  large 
  

   examples 
  from 
  Nelson 
  (South 
  Island) 
  all 
  tlie 
  tubercles, 
  even 
  those 
  on 
  

   the 
  branchial 
  regions, 
  tend 
  to 
  assume 
  the 
  form 
  of 
  sharp 
  spines. 
  Finally, 
  

   in 
  individuals 
  collected 
  at 
  Wellington 
  and 
  in 
  Pelorus 
  Eiver, 
  Marlbor- 
  

   ough 
  (localities 
  on 
  opposite 
  sides 
  of 
  Cook 
  Strait), 
  a 
  tendency 
  is 
  mani- 
  

   fested 
  to 
  variation 
  in 
  the 
  direction 
  of 
  Paranephrops 
  zealandicus, 
  inasmuch 
  

   as 
  the 
  lateral 
  rostral 
  spines 
  are 
  increased 
  in 
  number 
  and 
  reduced 
  to 
  

   short, 
  blunt 
  teeth, 
  and 
  the 
  antennal 
  scale 
  is 
  short 
  and 
  broad, 
  broadest 
  

   at 
  the 
  middle, 
  with 
  very 
  convex 
  internal 
  border. 
  The 
  largest 
  of 
  these 
  

   specimens 
  is 
  only 
  73 
  mm. 
  long. 
  ' 
  The 
  number 
  of 
  lateral 
  rostral 
  spines 
  

   varies 
  between 
  three 
  and 
  eight 
  on 
  each 
  side, 
  the 
  average 
  number 
  being 
  

   five. 
  The 
  lower 
  side 
  of 
  the 
  rostrum 
  is 
  in 
  many 
  cases 
  destitute 
  of 
  teeth. 
  

   In 
  three 
  out 
  of 
  the 
  four 
  specimens 
  from 
  Pelorus 
  River 
  the 
  median 
  carina 
  

   of 
  the 
  carapace 
  is 
  very 
  prominent, 
  and 
  extends 
  forward 
  from 
  the 
  gastric 
  

   area 
  half 
  way 
  to 
  the 
  tip 
  of 
  the 
  rostrum. 
  Usually 
  in 
  P. 
  planifrons 
  it 
  

   runs 
  forward 
  only 
  as 
  far 
  as 
  the 
  anterior 
  postorbital 
  spines. 
  

  

  The 
  most 
  southern 
  locality 
  where 
  P. 
  planifrons 
  has 
  been 
  found 
  is 
  

   Greymouth, 
  on 
  the 
  western 
  side 
  of 
  the 
  South 
  Island. 
  

  

  It 
  thus 
  appears, 
  as 
  was 
  first 
  pointed 
  out 
  by 
  Mr. 
  Chilton, 
  that 
  P. 
  

   planifrons 
  is 
  a 
  variable 
  species 
  distributed 
  throughout 
  the 
  whole 
  length 
  

   of 
  the 
  North 
  Island 
  (where 
  it 
  is 
  the 
  only 
  species 
  found) 
  and 
  through 
  

   the 
  northern 
  part 
  of 
  the 
  South 
  Island 
  as 
  far 
  south 
  as 
  Greymouth. 
  

   Hence 
  it 
  would 
  seem, 
  in 
  the 
  words 
  of 
  Mr. 
  Chilton, 
  "that 
  Cook 
  Strait 
  

   has 
  not 
  proved 
  so 
  great, 
  or 
  rather 
  so 
  old 
  a 
  barrier 
  to 
  these 
  crayfish 
  as 
  

   the 
  mountains 
  in 
  Nelson 
  forming 
  the 
  northern 
  continuation 
  of 
  the 
  

   Southern 
  Ali)s. 
  As 
  this 
  point 
  seemed 
  to 
  be 
  of 
  some 
  importance 
  in 
  

   connection 
  with 
  the 
  geographical 
  distribution 
  of 
  the 
  fauna 
  of 
  New 
  

   Zealand, 
  and 
  as 
  T 
  was 
  ignorant 
  of 
  the 
  configuration 
  of 
  that 
  part 
  of 
  the 
  

   South 
  Island, 
  I 
  applied 
  to 
  Professor 
  Hutton 
  for 
  information. 
  With 
  

   his 
  characteristic 
  kindness 
  and 
  promptness, 
  he 
  at 
  once 
  told 
  me 
  that 
  

   there 
  was 
  no 
  great 
  division 
  (by 
  mountains, 
  that 
  is,) 
  between 
  Nelson 
  

   and 
  Greymouth, 
  but 
  that 
  the 
  first 
  great 
  division 
  would 
  be 
  along 
  the 
  

   Kaikoura 
  Mountains 
  and 
  across 
  westerly 
  to 
  Mount 
  Franklin, 
  and 
  then 
  

   down 
  the 
  Spencer 
  Mountains 
  and 
  the 
  Southern 
  Alps; 
  though 
  the 
  part 
  

   between 
  the 
  Kaikoura 
  Mountains 
  and 
  Mount 
  Franklin 
  is 
  much 
  broken 
  

   by 
  rivers, 
  some 
  running 
  north 
  and 
  some 
  south. 
  He 
  also 
  told 
  me 
  

   that 
  several 
  North 
  Island 
  plants 
  extend 
  to 
  Nelson 
  and 
  down 
  the 
  

  

  