﻿akt. 
  3 
  STUDIES 
  ON 
  LARVAE 
  OF 
  CKABS 
  HYMAX 
  11 
  

  

  spine 
  and 
  are 
  hairy 
  along 
  their 
  distal 
  two-thirds. 
  The 
  exopodite 
  

   is 
  minute. 
  The 
  remaining 
  appendages 
  are 
  typical. 
  

  

  Thoracic 
  appendages. 
  — 
  These 
  are 
  typical, 
  except 
  that 
  the 
  third 
  

   maxilliped 
  is 
  unusually 
  far 
  advanced. 
  Its 
  bud 
  already 
  shows 
  a 
  

   distal 
  bifurcation. 
  

  

  Abdomen. 
  — 
  The 
  telson 
  (fig. 
  150) 
  is 
  bicornuate. 
  Each 
  cornu 
  bears 
  

   three 
  large 
  spines 
  medially, 
  one 
  minute 
  hair 
  dorsally, 
  and 
  two 
  small 
  

   hairs 
  laterally. 
  

  

  SECOXD 
  ZOEA 
  

  

  This 
  stage 
  has 
  not 
  been 
  described. 
  It 
  seems 
  to 
  have 
  been 
  over- 
  

   looked 
  by 
  Cano. 
  

  

  third 
  zoea 
  (figs. 
  126 
  and 
  127) 
  

  

  This 
  stage 
  is 
  characterized 
  by 
  the 
  increase 
  in 
  the 
  number 
  of 
  swim- 
  

   ming 
  hairs 
  to 
  9 
  or 
  10. 
  and 
  the 
  presence 
  of 
  abdominal 
  appendages 
  

   as 
  finger-shaped 
  buds. 
  

  

  CephaZothorax. 
  — 
  The 
  dorsal 
  and 
  rostral 
  spines 
  are 
  still 
  further 
  

   elongated. 
  The 
  eye 
  stalks 
  are 
  differentiated 
  and 
  the 
  eyes 
  are 
  mov- 
  

   able 
  although 
  the 
  stalks 
  can 
  not 
  be 
  lifted 
  from 
  the 
  orbits. 
  

  

  Cephalic 
  appendages. 
  — 
  The 
  antennule 
  (fig. 
  126) 
  shows 
  a 
  super- 
  

   ficial 
  differentiation 
  into 
  proximal 
  and 
  distal 
  portions. 
  The 
  proxi- 
  

   mal 
  portion 
  is 
  slightly 
  enlarged. 
  On 
  the 
  antenna 
  (fig. 
  126) 
  the 
  

   anlage 
  of 
  the 
  future 
  flagellum 
  appears 
  as 
  a 
  finger-shaped 
  bud 
  be- 
  

   tween 
  the 
  exopodite 
  and 
  the 
  spine. 
  

  

  Thoracic 
  appendages. 
  — 
  The 
  swimming 
  hairs 
  are 
  now 
  9 
  or 
  10. 
  

   The 
  third 
  maxilliped 
  and 
  the 
  remaining 
  thoracic 
  appendages 
  are 
  

   long, 
  finger-shaped 
  buds 
  and 
  their 
  points 
  are 
  indicated 
  by 
  super- 
  

   ficial 
  annulations. 
  

  

  Abdomen. 
  — 
  The 
  telson 
  is 
  separated 
  from 
  the 
  sixth 
  abdominal 
  seg- 
  

   ment 
  by 
  a 
  joint. 
  Each 
  segment 
  except 
  the 
  first 
  bears 
  a 
  pair 
  of 
  

   finger-shaped 
  buds 
  — 
  the 
  abdominal 
  appendages. 
  The 
  lateral 
  spines 
  

   on 
  the 
  third, 
  fourth, 
  and 
  fifth 
  segments 
  are 
  longer. 
  

  

  FOURTH 
  ZOEA 
  (fig. 
  128) 
  

  

  In 
  the 
  last 
  zoeal 
  stage 
  the 
  body 
  is 
  increased 
  in 
  size 
  and 
  weight 
  

   without 
  *a 
  corresponding 
  increase 
  in 
  the 
  size 
  of 
  the 
  carapace 
  spine 
  

   or 
  the 
  appendages. 
  

  

  Cephalic 
  appendages.— 
  -The 
  proximal 
  portion 
  of 
  the 
  antennule 
  

   (fig. 
  134) 
  is 
  composed 
  of 
  two 
  enlarged 
  segments. 
  The 
  distal 
  of 
  

   these 
  bears 
  two 
  rami, 
  an 
  inner 
  of 
  a 
  single 
  segment 
  bearing 
  sensory 
  

   hairs 
  and 
  an 
  outer 
  that 
  is 
  a 
  simple 
  bud. 
  

  

  The 
  flagellum 
  of 
  the 
  antenna 
  (fig. 
  134) 
  is 
  considerably 
  elongated. 
  

   The 
  mandible 
  (fig. 
  137) 
  shows 
  the 
  bud 
  of 
  the 
  future 
  palp. 
  The 
  

   maxillule 
  and 
  the 
  maxilla 
  (fig. 
  142) 
  reach 
  their 
  maximum 
  differ- 
  

   entiation. 
  

  

  