﻿DESCEIPTION 
  OF 
  A 
  NEW 
  CRUSTACEAN 
  OF 
  THE 
  GENUS 
  

   SPH.EEOMA 
  FEOM 
  A 
  WARM 
  SPRING 
  IN 
  NEW 
  MEXICO. 
  

  

  By 
  Harriet 
  Richardson. 
  

  

  A 
  NUMBER 
  OF 
  Specimens 
  of 
  the 
  following' 
  species 
  were 
  collected 
  by 
  

   Mr. 
  Theodore 
  D. 
  A. 
  Cockerell, 
  a 
  few 
  miles 
  west 
  of 
  Socorro, 
  New 
  ^Mexico, 
  

   where 
  they 
  were 
  found 
  living 
  in 
  a 
  warm 
  spring. 
  The 
  only 
  other 
  

   instance 
  of 
  a 
  fresh-water 
  Spha'roma 
  is 
  that 
  of 
  S. 
  dngesi, 
  a 
  Mexican 
  

   si:»ecies, 
  described 
  by 
  Adrien 
  Dollfns.^ 
  The 
  differences 
  between 
  his 
  

   species 
  and 
  the 
  present 
  oue 
  will 
  appear 
  in 
  the 
  description. 
  

  

  SPH/EROMA 
  THERMOPHILUM, 
  new 
  species. 
  

  

  Head 
  nearly 
  three 
  times 
  as 
  broad 
  as 
  long, 
  with 
  its 
  anterior 
  margin 
  

   widely 
  rounded. 
  Eyes 
  round 
  and 
  post 
  laterally 
  situated. 
  The 
  first 
  

   pair 
  of 
  antennji', 
  with 
  a 
  flagellum 
  of 
  eight 
  articles, 
  extends 
  to 
  the 
  middle 
  

   of 
  the 
  first 
  thoracic 
  segment. 
  The 
  second 
  pair 
  of 
  antenn.v 
  reach 
  the 
  

   posterior 
  margin 
  of 
  the 
  first 
  thoracic 
  segment; 
  the 
  flagellum 
  contains 
  

   eleven 
  articles. 
  

  

  The 
  thoracic 
  segments 
  are 
  all 
  similar 
  with 
  the 
  exception 
  of 
  the 
  first, 
  

   which 
  extends 
  laterally 
  around 
  the 
  head, 
  almost 
  touching 
  the 
  peduncle 
  

   of 
  the 
  first 
  pair 
  of 
  antenna^ 
  with 
  its 
  anterior 
  angle. 
  The 
  epimeral 
  parts 
  

   are 
  continuous 
  with 
  the 
  segments 
  with 
  no 
  indication 
  of 
  a 
  separation 
  

   from 
  them. 
  

  

  The 
  abdomen 
  is 
  formed 
  of 
  two 
  distinct 
  segments, 
  the 
  first 
  of 
  which 
  

   is 
  partly 
  covered 
  by 
  the 
  last 
  thoracic 
  segment, 
  the 
  second 
  is 
  sub-trian- 
  

   gular, 
  rounded 
  posteriorly. 
  The 
  internal 
  lamella 
  of 
  the 
  uropods 
  is 
  

   moderately 
  broad, 
  well 
  rounded, 
  and 
  extends 
  to 
  the 
  posterior 
  edge 
  of 
  

   the 
  last 
  abdominal 
  segment. 
  The 
  external 
  lamella 
  is 
  half 
  as 
  long 
  and 
  

   half 
  as 
  broad 
  as 
  the 
  internal 
  one, 
  and 
  is 
  more 
  pointed 
  at 
  its 
  extremity. 
  

  

  The 
  body 
  is 
  oblong-ovate 
  with 
  almost 
  parallel 
  sides. 
  Its 
  surface 
  is 
  

   entirely 
  smooth. 
  

  

  The 
  grayish-brown 
  color 
  of 
  the 
  body 
  is 
  everywhere 
  marked 
  with 
  small 
  

   black 
  spots 
  and 
  lines, 
  which 
  run 
  together, 
  forming 
  a 
  broad, 
  black 
  band 
  

  

  ' 
  Bull. 
  Soc. 
  Zool. 
  France, 
  1893, 
  XVIII, 
  p. 
  115, 
  figs. 
  1, 
  2. 
  

   [Advance 
  sheet 
  of 
  this 
  paper 
  was 
  published 
  February 
  6, 
  1897.] 
  

  

  Proceedings 
  U. 
  S. 
  National 
  Museum, 
  Vol. 
  XX— 
  No. 
  1128. 
  

   Proc. 
  N. 
  M. 
  vol. 
  XX 
  30 
  ^65 
  

  

  