﻿30 
  Mr. 
  R. 
  Guiney 
  on 
  some 
  Freshwater 
  

  

  (19) 
  Alonclla 
  diaphana, 
  King, 
  var. 
  punctata, 
  Daday. 
  

  

  A 
  few 
  specimens 
  identical 
  with 
  Daday's 
  species 
  A. 
  punc- 
  

   tata 
  were 
  taken 
  on 
  Feb. 
  12, 
  1907, 
  in 
  the 
  sweet-water 
  canal 
  

   at 
  Port 
  Said. 
  Alonella 
  punctata 
  has 
  been 
  recorded 
  by 
  Daday 
  

   from 
  Ceylon, 
  South 
  America, 
  and 
  East 
  Africa, 
  and 
  it 
  seems 
  

   probable 
  that 
  it 
  is 
  not 
  specifically 
  distinct 
  from 
  A. 
  diaphana, 
  

   King, 
  and 
  A. 
  davidi, 
  Richard. 
  Sars 
  (1901) 
  has 
  already 
  

   expressed 
  his 
  opinion 
  that 
  the 
  two 
  latter 
  are 
  identical 
  ; 
  and 
  

   the 
  description 
  given 
  by 
  Stingelin 
  (1904) 
  of 
  specimens 
  

   attributed 
  to 
  A. 
  davidi 
  and 
  taken 
  in 
  Java 
  and 
  Honolulu 
  

   seems 
  to 
  indicate 
  that 
  the 
  group 
  diaphana- 
  davidi 
  passes 
  by 
  

   intermediate 
  forms 
  into 
  punctata. 
  The 
  distinction 
  or 
  other- 
  

   wise 
  of 
  these 
  forms 
  turns 
  upon 
  the 
  presence 
  and 
  arrange- 
  

   ment 
  of 
  the 
  cilia 
  and 
  teeth 
  on 
  the 
  postabdomen. 
  The 
  dorsal 
  

   margin 
  of 
  the 
  postabdomen 
  bears 
  in 
  the 
  punctata 
  form 
  a 
  

   series 
  of 
  distinct 
  bundles 
  of 
  minute 
  denticles. 
  In 
  A. 
  diaphana 
  

   and 
  A. 
  davidi 
  these 
  denticles 
  seem 
  to 
  be 
  generally 
  arranged 
  

   singly, 
  though 
  in 
  A. 
  davidi 
  var. 
  iheringi 
  there 
  is 
  a 
  tendency 
  

   to 
  arrangement 
  in 
  groups. 
  In 
  Stingelin's 
  specimens 
  from 
  

   Java 
  and 
  Honolulu 
  the 
  denticles 
  are 
  almost 
  as 
  clearly 
  united 
  

   into 
  groups 
  as 
  in 
  the 
  true 
  punctata 
  form. 
  

  

  In 
  A. 
  davidi 
  and 
  A. 
  punctata 
  there 
  are 
  always 
  lateral 
  

   groups 
  of 
  delicate 
  cilia 
  ; 
  but 
  these 
  are 
  not 
  figured 
  by 
  Sars, 
  

   and 
  their 
  absence 
  constitutes 
  the 
  only 
  real 
  difference 
  between 
  

   A. 
  diaphana 
  and 
  A. 
  davidi. 
  I 
  am 
  disposed, 
  therefore, 
  to 
  

   regard 
  A. 
  punctata 
  and 
  A. 
  davidi 
  as 
  only 
  varieties 
  of 
  

   A. 
  diaphana, 
  King. 
  

  

  (20) 
  Dunhevedia 
  crassa, 
  King. 
  

  

  One 
  specimen 
  found 
  in 
  a 
  pool 
  in 
  the 
  Zoological 
  Gardens 
  

   at 
  Cairo. 
  

  

  (21) 
  Chydorus 
  sphcericus, 
  O. 
  F. 
  M. 
  

  

  Pools 
  by 
  the 
  road 
  to 
  the 
  Pyramids 
  j 
  Zoological 
  Gardens 
  ; 
  

   Dahchour. 
  Ephippial 
  females 
  were 
  found 
  on 
  Feb. 
  15 
  and 
  

   March 
  25, 
  1907, 
  and 
  Feb. 
  22, 
  1909. 
  

  

  (22) 
  Chydorus 
  sp. 
  ? 
  (PI. 
  II. 
  fig. 
  6.) 
  

  

  The 
  shell 
  of 
  a 
  single 
  decayed 
  specimen 
  of 
  a 
  species 
  of 
  

   Chydorus 
  was 
  found 
  in 
  a 
  collection 
  made 
  in 
  the 
  Zoological 
  

   Gardens. 
  

  

  The 
  specimen 
  appears 
  to 
  resemble 
  Chydorus 
  globosus 
  

   very 
  closely, 
  but 
  differs 
  from 
  it 
  to 
  some 
  extent 
  in 
  the 
  slight 
  

  

  