﻿26 
  Mr. 
  R. 
  Gurney 
  on 
  some 
  Freshwater 
  

  

  features 
  of 
  the 
  country, 
  it 
  is 
  remarkably 
  uniform 
  in 
  distri- 
  

   bution. 
  The 
  long, 
  unvaried, 
  valley 
  of 
  the 
  Nile 
  seems, 
  both 
  

   for 
  the 
  fauna 
  and 
  the 
  flora, 
  to 
  effect 
  a 
  transition 
  between 
  

   the 
  Ethiopian 
  and 
  the 
  Palsearctic 
  regions, 
  and 
  to 
  produce 
  a 
  

   uniformity 
  which 
  can 
  rarely 
  be 
  met 
  with 
  in 
  other 
  parts 
  of 
  

   the 
  world. 
  Such 
  a 
  uniformity 
  with 
  regard 
  to 
  the 
  Ento- 
  

   mostraca 
  is 
  only 
  to 
  be 
  expected, 
  since 
  all 
  the 
  water 
  of 
  the 
  

   country 
  is 
  supplied 
  from 
  the 
  same 
  source, 
  and 
  the 
  majority 
  

   of 
  the 
  smaller 
  pools 
  are 
  only 
  temporary, 
  drying 
  up 
  in 
  the 
  

   summer. 
  Where 
  there 
  are 
  permanent 
  pools 
  of 
  water 
  in 
  

   which 
  there 
  is 
  vegetation 
  the 
  fauna 
  is 
  more 
  varied, 
  but, 
  on 
  

   the 
  whole, 
  the 
  species 
  are 
  evenly 
  distributed. 
  

  

  List 
  of 
  Species. 
  

  

  (1) 
  Diaphanosoma 
  brachyurum, 
  Lievin. 
  

  

  Abundant 
  in 
  pools 
  by 
  the 
  road 
  to 
  the 
  Pyramids 
  of 
  Gizeh, 
  

   and 
  also 
  found 
  in 
  a 
  canal 
  at 
  Lecht. 
  A 
  few 
  males 
  were 
  

   found 
  among 
  the 
  specimens 
  taken 
  on 
  Feb. 
  15 
  in 
  the 
  former 
  

   place. 
  

  

  (2) 
  Diaphanosoma 
  excisum, 
  Sars. 
  

  

  A 
  number 
  of 
  specimens 
  of 
  this 
  species 
  were 
  found 
  in 
  the 
  

   collections 
  from 
  the 
  Blue 
  and 
  the 
  White 
  Nile. 
  Ekman 
  

   (1901) 
  has 
  described 
  a 
  variety 
  (var. 
  longiremis) 
  from 
  the 
  

   White 
  Nile 
  which 
  differs 
  from 
  the 
  type 
  in 
  the 
  greater 
  length 
  

   of 
  the 
  antennae 
  and 
  the 
  presence 
  on 
  the 
  postabdomen 
  of 
  a 
  

   few 
  short 
  hairs. 
  My 
  own 
  specimens 
  have 
  the 
  shorter 
  an- 
  

   tennae 
  of 
  the 
  type, 
  but 
  the 
  same 
  hairs 
  on 
  the 
  postabdomen 
  

   as 
  Ekman 
  describes. 
  

  

  (3) 
  Daphnia 
  lumholtzi, 
  Sars. 
  

  

  A 
  few 
  specimens, 
  including 
  males 
  and 
  ephippial 
  females, 
  

   were 
  taken 
  in 
  a 
  pool 
  near 
  the 
  Pyramids, 
  and 
  ephippia 
  which 
  

   I 
  refer 
  to 
  this 
  species 
  were 
  found 
  in 
  a 
  pool 
  at 
  Dahchour. 
  A 
  

   single 
  adult 
  specimen, 
  somewhat 
  decayed, 
  was 
  found 
  in 
  the 
  

   Nile 
  at 
  Luxor. 
  

  

  (4) 
  Daphnia 
  longispina, 
  O. 
  F. 
  M. 
  

  

  Pools 
  near 
  the 
  Pyramids, 
  pool 
  at 
  Dahchour, 
  and 
  in 
  the 
  

   Nile 
  at 
  Kous. 
  

  

  (5) 
  Daphnia 
  longispina, 
  var. 
  cucullata, 
  Sars. 
  

  

  I 
  have 
  a 
  rough 
  drawing 
  by 
  my 
  brother 
  of 
  a 
  species 
  of 
  

  

  