﻿10 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  C7 
  

  

  depressus 
  are 
  so 
  close 
  that 
  one 
  would 
  have 
  great 
  difficulty 
  in 
  dis- 
  

   tinguishing 
  the 
  two, 
  except 
  that 
  in 
  herbstii 
  the 
  antennule 
  does 
  not 
  

   have 
  a 
  pigment 
  spot. 
  

  

  first 
  zoea 
  (fig*. 
  110 
  and 
  117) 
  

  

  The 
  resemblance 
  of 
  the 
  first 
  zoea 
  to 
  that 
  of 
  depressus 
  is 
  very 
  clost. 
  

   They 
  may 
  be 
  distinguished 
  by 
  the 
  absence 
  of 
  pigment 
  on 
  the 
  anten- 
  

   nule 
  of 
  herbstii 
  and 
  by 
  several 
  relative 
  though 
  pronounced 
  differ- 
  

   ences. 
  

  

  The 
  dorsal 
  and 
  rostral 
  spines 
  are 
  slender 
  as 
  in 
  depressus 
  and 
  the 
  

   dorsal 
  shows 
  a 
  terminal 
  hook. 
  However, 
  both 
  are 
  distinctly 
  shorter 
  

   than 
  in 
  depressus. 
  The 
  antennae 
  are 
  shorter 
  than 
  in 
  depressus 
  and 
  

   the 
  exopodite 
  is 
  much 
  larger. 
  

  

  The 
  remaining 
  appendages 
  and 
  the 
  abdomen 
  are 
  like 
  those 
  of 
  

   depressus 
  except 
  in 
  minute 
  details. 
  

  

  HEXAPANOPEUS 
  ANGUSTIFRONS 
  (Benedict 
  and 
  Rathbun) 
  

  

  Plate 
  1, 
  figs. 
  6, 
  10, 
  12, 
  16, 
  20; 
  plate 
  2, 
  figs. 
  22, 
  26, 
  30, 
  34 
  

  

  This 
  species 
  is 
  rare 
  at 
  Beaufort. 
  A 
  single 
  female 
  was 
  identified 
  

   by 
  Dr. 
  W. 
  P. 
  Hay 
  and 
  presented 
  to 
  me 
  in 
  1916. 
  The 
  eggs 
  hatched 
  

   but 
  none 
  of 
  the 
  prezoeas 
  molted. 
  None 
  of 
  the 
  zoeal 
  stages 
  have 
  

   been 
  found 
  in 
  the 
  tow. 
  

  

  PKEZOEA 
  (fig. 
  22) 
  

  

  The 
  prezoea 
  resembles 
  that 
  of 
  sayi 
  quite 
  closely 
  in 
  size 
  and 
  gen- 
  

   eral 
  appearance. 
  It 
  may 
  be 
  distinguished 
  by 
  details 
  of 
  structure. 
  

   The 
  lobe 
  of 
  the 
  prezoeal 
  cuticle 
  of 
  the 
  antenna 
  (fig. 
  6) 
  has 
  four 
  

   large 
  digitations 
  instead 
  of 
  three. 
  The 
  telson 
  (fig. 
  34) 
  is 
  bicornu- 
  

   ate, 
  but 
  prezoeal^cuticle 
  of 
  either 
  ramus 
  carries 
  six 
  hairs 
  or 
  processes 
  

   instead 
  of 
  seven. 
  

  

  Genus 
  XANTHO 
  

  

  Plate 
  11; 
  plate 
  12, 
  figs. 
  141-151 
  

  

  The 
  development 
  of 
  Xantho 
  has 
  been 
  studied 
  by 
  Couch, 
  Gourret, 
  

   and 
  Cano. 
  Cano 
  has 
  given 
  the 
  most 
  nearly 
  complete 
  description 
  of 
  

   its 
  metamorphosis. 
  He 
  studied 
  X. 
  rividosus, 
  X. 
  floridus, 
  and 
  X. 
  

   tubereulatus 
  but 
  did 
  not 
  distinguish 
  between 
  the 
  larval 
  stages 
  of 
  the 
  

   different 
  species. 
  

  

  The 
  zoeas 
  of 
  Xantho 
  resemble 
  those 
  of 
  Neopanope 
  quite 
  closely. 
  

   They 
  have 
  the 
  same 
  type 
  of 
  carapace 
  spines 
  and 
  of 
  antennae. 
  

  

  FIRST 
  ZOEA 
  (fig. 
  125) 
  

  

  Cephalotliorax. 
  — 
  The 
  rostral 
  and 
  dorsal 
  spines 
  are 
  long 
  and 
  

   slender. 
  The 
  lateral 
  spines 
  are 
  short 
  and 
  slender. 
  

  

  Cephalic 
  appendages. 
  — 
  The 
  antennules 
  (fig. 
  138) 
  have 
  the 
  typical 
  

   conical 
  form. 
  The 
  antennae 
  (fig. 
  133) 
  are 
  as 
  long 
  as 
  the 
  rostral 
  

  

  