﻿art. 
  3 
  STUDIES 
  ON 
  LARVAE 
  OF 
  CRABS 
  HYMAN 
  9 
  

  

  they 
  may 
  be 
  distinguished 
  from 
  those 
  of 
  Neopanope 
  at 
  all 
  stages, 
  

   including 
  the 
  megalops, 
  by 
  the 
  simple 
  fact 
  that 
  all 
  stages 
  of 
  the 
  

   zoea 
  and 
  megalops 
  of 
  Eurypanopeus 
  have 
  a 
  pigment 
  spot 
  on 
  the 
  

   antennule. 
  

  

  Birge 
  mentions 
  the 
  first 
  zoea 
  of 
  this 
  species 
  and 
  gives 
  certain 
  

   characters 
  by 
  which 
  it 
  may 
  be 
  distinguished 
  from 
  sayi. 
  I 
  have 
  

   studied 
  only 
  the 
  prezoea 
  and 
  first 
  zoea 
  in 
  detail, 
  but 
  have 
  identifed 
  

   the 
  remaining 
  zoea 
  and 
  megalops 
  stages 
  in 
  specimens 
  from 
  the 
  tow. 
  

   Superficially, 
  the 
  development 
  seems 
  to 
  be 
  the 
  same 
  as 
  in 
  sayi. 
  The 
  

   characteristic 
  differences 
  between 
  the 
  first 
  zoeal 
  forms 
  hold 
  

   throughout. 
  

  

  TREZOEA 
  (fig. 
  2) 
  

  

  The 
  prezoea 
  is 
  appreciably 
  larger 
  and 
  more 
  robust 
  than 
  that 
  of 
  

   sayi, 
  but 
  it 
  agrees 
  in 
  structure 
  except 
  in 
  certain 
  details. 
  

  

  The 
  prezoeal 
  antennal 
  cuticle 
  (fig. 
  4) 
  shows 
  four 
  large 
  digita- 
  

   tions 
  on 
  the 
  lobe 
  instead 
  of 
  three 
  large 
  ones 
  and 
  one 
  minute 
  one. 
  

   The 
  remaining 
  appendages 
  approximate 
  those 
  of 
  sayi 
  very 
  closely, 
  

   differing 
  only 
  relatively. 
  In 
  the 
  telson 
  (fig. 
  32) 
  of 
  depresses 
  the 
  

   spines 
  of 
  the 
  prezoeal 
  cuticle 
  are 
  longer 
  than 
  in 
  sayi. 
  

  

  first 
  zoea 
  (figs. 
  106 
  and 
  107) 
  

  

  In 
  general 
  the 
  zoea 
  shows 
  the 
  features 
  that 
  characterize 
  sayi. 
  

   There 
  are 
  differences 
  in 
  detail, 
  however, 
  that 
  make 
  the 
  zoeas 
  more 
  

   easily 
  distinguishable 
  than 
  the 
  adults. 
  

  

  Cephalothorax. 
  — 
  The 
  dorsal 
  and 
  rostral 
  spines 
  are 
  very 
  long 
  and 
  

   slender. 
  The 
  dorsal 
  spine 
  is 
  strongly 
  hooked 
  at 
  its 
  extremity. 
  

  

  Cephalic 
  appendages. 
  — 
  The 
  antennules 
  are 
  of 
  the 
  usual 
  type, 
  but 
  

   each 
  bears 
  a 
  large 
  pigment 
  spot 
  distally 
  (fig. 
  108). 
  The 
  antennae 
  

   (fig. 
  109) 
  are 
  long 
  and 
  slender 
  and 
  gently 
  curved. 
  They 
  bear 
  bristles 
  

   for 
  nearly 
  a 
  third 
  of 
  their 
  length 
  distally. 
  

  

  There 
  is 
  nothing 
  about 
  the 
  remaining 
  appendages 
  or 
  the 
  abdomen 
  

   that 
  would 
  distinguish 
  this 
  species 
  from 
  sayi. 
  

  

  PANOPEUS 
  HERBSTII 
  (Milne 
  Edwards) 
  

  

  Plate 
  1, 
  figs. 
  5, 
  9, 
  15, 
  19; 
  plate 
  2, 
  figs. 
  21, 
  25, 
  29, 
  33; 
  plate 
  10 
  

  

  Panopeus 
  herbstii 
  is 
  the 
  most 
  abundant 
  Xanthid 
  at 
  Beaufort. 
  It 
  

   swarms 
  under 
  shells 
  and 
  debris 
  all 
  along 
  the 
  shores. 
  I 
  have 
  studied 
  

   the 
  development 
  up 
  to 
  the 
  megalops 
  stage, 
  but 
  only 
  the 
  prezoeal 
  and 
  

   first 
  zoeal 
  stages 
  in 
  detail. 
  These 
  resemble 
  similar 
  stages 
  in 
  depressus 
  

   quite 
  closely. 
  The 
  remaining 
  zoeal 
  stages 
  develop 
  as 
  in 
  sayi. 
  The 
  

   characteristics 
  that 
  distinguish 
  the 
  first 
  zoea 
  distinguish 
  all 
  subse- 
  

   quent 
  zoeal 
  stages. 
  

  

  PREZOEA 
  (fig. 
  21) 
  

  

  The 
  prezoea 
  is 
  large, 
  as 
  in 
  depressus, 
  and 
  is 
  quite 
  robust. 
  The 
  

   carapace 
  is 
  in 
  an 
  unusually 
  immature 
  condition, 
  extending 
  poste- 
  

   riorly 
  hardly 
  beyond 
  the 
  heart. 
  The 
  resemblances 
  to 
  the 
  prezoea 
  of 
  

  

  22246—25 
  2 
  

  

  