﻿art. 
  3 
  STUDIES 
  ON 
  LARVAE 
  OF 
  CRABS 
  HYMAN 
  3 
  

  

  In 
  Neopanope 
  the 
  prezoea 
  is 
  followed 
  by 
  four 
  zoeal 
  stages 
  and 
  

   at 
  least 
  two 
  megalops 
  stages. 
  The 
  juvenile 
  history 
  of 
  the 
  crab 
  

   stages 
  has 
  not 
  been 
  reported. 
  

  

  NEOPANOPE 
  TEXANA 
  SAYI 
  (Smith) 
  

  

  Plate 
  1, 
  figs. 
  1, 
  3, 
  7, 
  11, 
  13, 
  17 
  ; 
  plate 
  2, 
  figs. 
  23, 
  27, 
  31 
  ; 
  plates 
  3-8 
  

  

  The 
  larval 
  history 
  of 
  this 
  species 
  has 
  been 
  reported 
  very 
  fully 
  

   by 
  Birge. 
  The 
  writer 
  has 
  checked 
  over 
  the 
  development 
  on 
  mate- 
  

   rial 
  secured 
  at 
  Beaufort, 
  where 
  the 
  species 
  is 
  abundant. 
  The 
  follow- 
  

   ing 
  description 
  varies 
  from 
  that 
  of 
  Birge 
  in 
  a 
  number 
  of 
  details. 
  

  

  rilBZOEA 
  (fig. 
  1) 
  

  

  The 
  larva 
  hatches 
  with 
  the 
  embryonic 
  cuticle 
  still 
  intact. 
  It 
  is 
  

   generally 
  sluggish 
  at 
  first 
  but 
  becomes 
  more 
  active 
  and 
  — 
  under 
  

   laboratory 
  conditions 
  — 
  sheds 
  the 
  cuticle 
  in 
  a 
  few 
  hours. 
  

  

  Gephalothorax. 
  — 
  The 
  cuticle 
  covering 
  the 
  cephalothorax 
  is 
  smooth 
  

   and 
  without 
  processes, 
  but 
  the 
  processes 
  of 
  the 
  first 
  zoeal 
  stage 
  

   may 
  be 
  seen 
  folded 
  beneath 
  it. 
  The 
  dorsal 
  spine 
  is 
  bent 
  forward. 
  

   It 
  is 
  telescoped 
  upon 
  itself 
  and 
  is 
  quite 
  wrinkled. 
  The 
  lateral 
  spines 
  

   are 
  quite 
  difficult 
  to 
  see 
  but 
  are 
  present, 
  folded 
  against 
  the 
  side 
  of 
  

   the 
  body. 
  The 
  rostral 
  spine 
  is 
  wrinkled 
  and 
  telescoped 
  like 
  the 
  

   dorsal 
  spine. 
  It 
  is 
  folded 
  posteriorly 
  and 
  ventrally, 
  lying 
  between 
  

   the 
  bases 
  of 
  the 
  appendages. 
  

  

  Cephalic 
  appendages. 
  — 
  The 
  antennular 
  process 
  (fig. 
  3) 
  of 
  the 
  

   embryonic 
  cuticle 
  is 
  greatly 
  prolonged. 
  It 
  is 
  bifurcated 
  distally. 
  

   One 
  ramus 
  is 
  much 
  longer 
  and 
  is 
  sparsely 
  hairy 
  while 
  the 
  other 
  is 
  

   short, 
  blunt, 
  and 
  smooth. 
  The 
  antennule 
  of 
  the 
  first 
  zoea 
  extends 
  

   out 
  into 
  the 
  process, 
  reaching 
  to 
  the 
  point 
  of 
  bifurcation. 
  At 
  its 
  

   tip 
  it 
  bears 
  several 
  sensory 
  hairs 
  that 
  are 
  partially 
  invaginated. 
  

  

  The 
  prezoeal 
  antennal 
  process 
  (fig. 
  7) 
  is 
  also 
  entirely 
  different 
  

   in 
  shape 
  from 
  the 
  zoeal 
  antenna 
  that 
  it 
  incloses. 
  The 
  prozoeal 
  

   antenna 
  is 
  biramous. 
  One 
  ramus 
  is 
  a 
  simple, 
  smooth, 
  blunt 
  process 
  

   into 
  which 
  the 
  great 
  spine 
  of 
  the 
  zoeal 
  antenna 
  extends. 
  The 
  

   other 
  ramus 
  carries 
  three 
  sparsely 
  hairy 
  spines 
  that 
  are 
  digitately 
  

   arranged. 
  A 
  fourth 
  spine 
  is 
  present 
  as 
  a 
  minute, 
  smooth 
  process. 
  

   The 
  antenna 
  of 
  the 
  zoea 
  is 
  seen 
  within 
  the 
  cuticle. 
  It 
  is 
  wrinkled 
  

   and 
  its 
  distal 
  two-thirds 
  is 
  telescoped 
  on 
  itself. 
  

  

  The 
  mandibles 
  (fig. 
  11), 
  the 
  maxillules 
  (fig. 
  13), 
  and 
  the 
  maxillae 
  

   (fig. 
  17) 
  are 
  inclosed 
  in 
  simple 
  sac-like 
  prolongations 
  of 
  the 
  cuticle. 
  

   Each 
  is 
  typically 
  brachyuran 
  except 
  that 
  the 
  hairs 
  are 
  invaginated. 
  

  

  Thoracic 
  appendages. 
  — 
  Four 
  pairs 
  of 
  thoracic 
  appendages 
  are 
  

   recognizable, 
  three 
  pairs 
  of 
  maxillipeds 
  and 
  the 
  chelipeds. 
  Each 
  

   is 
  inclosed 
  in 
  a 
  closely 
  fitting, 
  unsegmented 
  sac 
  of 
  the 
  embryonic 
  

  

  