﻿A 
  NEW 
  CRAYFISH 
  FROM 
  TEXAS 
  — 
  HOBBS 
  227 
  

  

  pimctations 
  on 
  either 
  side 
  of 
  keel. 
  Lower 
  svirface 
  with 
  a 
  mesial 
  keel, 
  

   otherwise 
  punctate 
  ; 
  immediate!}' 
  mesiad 
  and 
  above 
  the 
  keel 
  is 
  a 
  mat 
  of 
  

   plumose 
  setae. 
  

  

  Carpus 
  of 
  first 
  left 
  pereiopod 
  longer 
  than 
  wide, 
  longer 
  than 
  inner 
  

   margin 
  of 
  palm 
  of 
  chela; 
  well-defined 
  longitudinal 
  furrow 
  above. 
  

   Lateral 
  portion 
  of 
  upper 
  surface 
  and 
  lateral 
  surface 
  punctate; 
  mesial 
  

   portion 
  of 
  up)per 
  surface 
  with 
  a 
  group 
  of 
  nine 
  small 
  tubercles, 
  below 
  

   which 
  is 
  a 
  row 
  of 
  four 
  larger 
  ones, 
  the 
  distal 
  member 
  of 
  this 
  row 
  de- 
  

   cidedly 
  larger 
  than 
  the 
  others 
  and 
  spikelike 
  ; 
  lower 
  mesial 
  margin 
  with 
  

   five 
  small 
  tubercles 
  and 
  the 
  lower 
  cephalic 
  margin 
  with 
  two 
  large 
  ones. 
  

  

  Merus 
  of 
  first 
  left 
  pereiopod 
  sparsely 
  punctate 
  mesiad 
  and 
  laterad. 
  

   LoM-er 
  mesial 
  margin 
  with 
  lo 
  tubercles, 
  the 
  penultimate 
  the 
  largest; 
  

   lower 
  lateral 
  margin 
  with 
  five 
  small 
  ones. 
  Upper 
  margin 
  of 
  merus 
  

   emarginate 
  with 
  two 
  small 
  tubercles 
  slightly 
  proximad 
  of 
  distal 
  mar- 
  

   gin, 
  and 
  a 
  transverse 
  row 
  of 
  three 
  small 
  ones 
  on 
  distal 
  margin. 
  

   -Margins 
  of 
  maxillipeds 
  and 
  sec/Dud 
  pereiopods 
  bearing 
  long 
  hairs. 
  

  

  Hooks 
  present 
  on 
  ischiopodites 
  of 
  third 
  pereiopods 
  only; 
  hooks 
  

   slender. 
  

  

  First 
  pleopod 
  reaching 
  to 
  base 
  of 
  third 
  pereiopods 
  and 
  terminating 
  

   in 
  two 
  distinct 
  parts. 
  Central 
  projection 
  corneous 
  and 
  bladelike, 
  

   recurved 
  at 
  slightly 
  greater 
  than 
  a 
  right 
  angle 
  to 
  the 
  main 
  shaft; 
  

   caudodistal 
  margin 
  entire. 
  Mesial 
  process 
  grooved 
  so 
  as 
  to 
  appear 
  

   twisted, 
  not 
  bulbous, 
  and 
  lies 
  parallel 
  to 
  the 
  central 
  projection. 
  

  

  Allotypic 
  female. 
  — 
  Differs 
  from 
  the 
  holotype 
  in 
  the 
  following 
  re- 
  

   spects: 
  Cephalic 
  section 
  of 
  telson 
  with 
  2 
  spines 
  in 
  each 
  caudolateral 
  

   corner. 
  Antennae 
  extend 
  caudad 
  to 
  third 
  abdominal 
  segment. 
  Op- 
  

   posable 
  margin 
  of 
  dactyl 
  with 
  10 
  tubercles 
  ; 
  however, 
  third 
  from 
  base 
  

   largest 
  as 
  in 
  holotype. 
  Row 
  of 
  tubercles 
  on 
  upper 
  surface 
  of 
  dactyl 
  

   above 
  the 
  mesial 
  row 
  consisting 
  of 
  4 
  instead 
  of 
  5. 
  Opposable 
  margin 
  

   of 
  immovable 
  finger 
  with 
  4 
  tubercles. 
  Slight 
  differences 
  in 
  tubercle 
  

   counts 
  on 
  carpus 
  and 
  merus; 
  however, 
  the 
  larger 
  ones 
  as 
  described 
  

   for 
  holotype. 
  See 
  fig. 
  17, 
  h 
  for 
  contours 
  of 
  annulus 
  ventralis. 
  The 
  

   left 
  chela 
  of 
  the 
  allotype 
  is 
  abnormal, 
  perhaps 
  a 
  regenerated 
  one. 
  

  

  Movphotypic 
  male, 
  form, 
  II. 
  — 
  Differs 
  from 
  the 
  holotype 
  in 
  the 
  fol- 
  

   lowing 
  respects 
  : 
  Cephalic 
  section 
  of 
  telson 
  with 
  2 
  spines 
  in 
  each 
  caudo- 
  

   lateral 
  corner. 
  Antennae 
  extend 
  caudad 
  to 
  third 
  abdominal 
  segment. 
  

   Opposable 
  margin 
  of 
  dactyl 
  with 
  8 
  or 
  10 
  tubercles, 
  one 
  decidedly 
  larger 
  

   than 
  the 
  others 
  in 
  the 
  same 
  position 
  as 
  in 
  holotype. 
  Mesial 
  margins 
  

   of 
  dactyls 
  with 
  9 
  or 
  10 
  tubercles. 
  Left 
  dactyl 
  with 
  6 
  tubercles 
  in 
  the 
  

   row 
  above 
  mesial 
  row. 
  Opposable 
  margin 
  of 
  immovable 
  finger 
  with 
  4 
  

   tubercles, 
  the 
  proximal 
  2 
  larger 
  as 
  in 
  holotype. 
  Slight 
  differences 
  

   in 
  tubercle 
  counts 
  on 
  carpus 
  and 
  merus; 
  however, 
  the 
  larger 
  ones 
  as 
  

   described 
  for 
  holotype. 
  First 
  pleopod 
  differing 
  from 
  that 
  of 
  holotype 
  

   in 
  that 
  there 
  is 
  less 
  twist 
  to 
  the 
  mesial 
  process, 
  and 
  the 
  central 
  projec- 
  

  

  