﻿692 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  vouxx. 
  

  

  The 
  brancliial 
  formula 
  for 
  F. 
  agassizii 
  is 
  as 
  follows 
  : 
  

  

  Aethrobranciii^. 
  

  

  Somite. 
  PoDOBRANCHiiE. 
  . 
  Pleukobhanchi^. 
  

  

  Anterior. 
  Posterior. 
  

  

  VII. 
  . 
  . 
  . 
  0(ep) 
  ..0....0....0 
  = 
  0(ep) 
  

   VIII. 
  ...1....1....0....0 
  =2 
  

   IX. 
  ... 
  1 
  .... 
  1 
  .... 
  1 
  .... 
  =3 
  

  

  XL 
  ... 
  1 
  .... 
  1 
  .... 
  1 
  .... 
  1 
  =4 
  

  

  XII. 
  ...1....1....1....1 
  =4 
  

  

  XIII. 
  ... 
  1 
  .... 
  1 
  ....)•.... 
  1 
  = 
  3+r 
  

  

  XIV. 
  ... 
  .... 
  .... 
  

  

  6+ci> 
  + 
  6 
  + 
  4+r 
  + 
  4 
  = 
  20+r+cp 
  

  

  The 
  epipod 
  of 
  the 
  first 
  maxilliped 
  is 
  destitute 
  of 
  branchial 
  filaments, 
  

   a 
  condition 
  rarely 
  found 
  among 
  the 
  Parastacinw. 
  The 
  stems 
  of 
  the 
  

   podobrauchitTB 
  are 
  alate. 
  The 
  posterior 
  arthrobrauchia 
  of 
  the 
  thir- 
  

   teenth 
  somite 
  is 
  a 
  simple, 
  slender 
  filament. 
  Coxopoditic 
  sette 
  long, 
  

   hooked 
  at 
  the 
  free 
  end. 
  

  

  Habitat.— 
  T'Alciilnmno, 
  Chile, 
  No. 
  3400, 
  Coll. 
  Mus. 
  Comp. 
  Zool., 
  (Hass- 
  

   ler 
  Exped., 
  April, 
  1872). 
  Nine 
  males, 
  eight 
  females 
  (two 
  ovig.). 
  

  

  The 
  egg 
  measures 
  3.5 
  by 
  2.5 
  mm. 
  

  

  In 
  nine 
  out 
  of 
  fourteen 
  specimens 
  the 
  larger 
  claw 
  is 
  on 
  the 
  left 
  side. 
  

  

  Judging 
  from 
  the 
  form 
  of 
  the 
  body, 
  this 
  is 
  probably 
  not 
  a 
  burrowing 
  

   species. 
  

  

  Museum 
  of 
  Comparative 
  Zoology, 
  

  

  Cambridge, 
  Massachusetts, 
  August 
  1, 
  1896. 
  

  

  EXPLANATION 
  OF 
  PLATES. 
  

  

  [^OTE. 
  — 
  All 
  of 
  the 
  figures 
  were 
  drawn 
  by 
  James 
  H. 
  Emerton. 
  Owing 
  to 
  errors 
  in 
  the 
  photographic 
  

   reduction 
  of 
  the 
  original 
  drawings, 
  it 
  is 
  impossible 
  to 
  give 
  the 
  exact 
  scale 
  for 
  many 
  of 
  the 
  figures 
  

   in 
  these 
  plates.] 
  

  

  Plate 
  LXII. 
  

  

  Fig. 
  1. 
  Cambarus 
  acherontis 
  'L'6nn\i6vg. 
  Female. 
  Gum 
  Cave, 
  Citrus 
  Comity, 
  Florida. 
  

   Reduced. 
  (U.S.N.M.) 
  

  

  2. 
  The 
  same, 
  lateral 
  view 
  of 
  the 
  head. 
  

  

  3. 
  Camharus 
  aelicrontls 
  Louuberg. 
  First 
  abdominal 
  appendage 
  of 
  a 
  young 
  

  

  male, 
  Form 
  II, 
  from 
  the 
  outside. 
  

  

  4. 
  The 
  same, 
  from 
  the 
  inside. 
  

  

  5. 
  Cambarus 
  acherontis 
  Liiunberg. 
  Annulus 
  ventralis 
  of 
  adult 
  female. 
  

  

  6. 
  Camharus 
  longidigitiis 
  Faxon. 
  Male, 
  Form 
  11. 
  White 
  River, 
  Arkansas. 
  

  

  Reduced. 
  (No. 
  4364, 
  Mus. 
  Comp. 
  Zool.) 
  

  

  7. 
  The 
  same, 
  first 
  abdominal 
  appendage 
  from 
  the 
  outside. 
  

  

  8. 
  The 
  same, 
  first 
  abdominal 
  appendage 
  from 
  the 
  inside. 
  

  

  9. 
  Cambarus 
  longidUjitm 
  Faxon. 
  Annulus 
  ventralis 
  of 
  female. 
  

  

  Plate 
  LXIII. 
  

  

  Fig. 
  1. 
  Camharus(arina1us¥a,^o\i. 
  Male, 
  Form 
  I. 
  Guadalajara, 
  ^lexico. 
  Xf. 
  (No. 
  

   17699, 
  U.S.N.M.) 
  

  

  2. 
  The 
  same, 
  first 
  abdominal 
  appendage 
  from 
  the 
  outside. 
  

  

  3. 
  The 
  same, 
  first 
  abdominal 
  appendage 
  from 
  the 
  inside. 
  

  

  