﻿392 
  Mr. 
  Martin 
  E. 
  Mosely 
  on 
  a 
  New 
  Hydroptila. 
  

  

  two 
  slight 
  projections. 
  Two 
  processes 
  with 
  the 
  outer 
  

   margins 
  sinuate 
  arise 
  from 
  the 
  edges 
  of 
  the 
  ninth 
  segment, 
  

   parallel 
  with 
  and 
  on 
  each 
  side 
  of 
  the 
  base 
  of 
  the 
  dorsal 
  

   plate. 
  From 
  a 
  lateral 
  aspect 
  these 
  side 
  pieces 
  appear 
  to 
  

   be 
  triangular. 
  The 
  penis 
  towards 
  its 
  apex 
  is 
  bent 
  sharply 
  

   round 
  at 
  right 
  angles 
  to 
  the 
  main 
  stem, 
  resembling 
  in 
  this 
  

   respect 
  several 
  other 
  species 
  in 
  the 
  genus. 
  The 
  inferior 
  

   appendages 
  are 
  large, 
  and, 
  viewed 
  laterally, 
  the 
  extremities 
  

   are 
  seen 
  to 
  be 
  considerably 
  broadened 
  and 
  furnished 
  with 
  

   two 
  dark 
  warts, 
  or 
  blunt 
  spines, 
  which, 
  from 
  a 
  dorsal 
  or 
  

   ventral 
  aspect, 
  appear, 
  one 
  at 
  the 
  extreme 
  apex, 
  and 
  the 
  

   other 
  a 
  short 
  distance 
  below 
  it. 
  From 
  the 
  side 
  one 
  wart 
  

   appears 
  on 
  the 
  upper 
  angle, 
  and 
  the 
  other 
  a 
  short 
  distance 
  

   from 
  the 
  lower 
  angle 
  along 
  the 
  lower 
  margin. 
  The 
  upper 
  

   margin 
  is 
  armed 
  throughout 
  its 
  length 
  with 
  five 
  or 
  six 
  

   widely 
  separated 
  spines 
  or 
  strong 
  hairs. 
  There 
  is 
  a 
  hghtly 
  

   chitinised 
  ventral 
  plate, 
  somewhat 
  excised 
  towards 
  the 
  

   middle, 
  

  

  I 
  have 
  not 
  been 
  able 
  to 
  distinguish 
  the 
  $ 
  from 
  that 
  of 
  

   //. 
  sparsa. 
  

  

  For 
  purposes 
  of 
  comparison, 
  figures 
  of 
  the 
  genitalia 
  of 
  

   both 
  H. 
  sparsa 
  and 
  H. 
  simulans 
  are 
  given. 
  

  

  I 
  have 
  in 
  my 
  collection 
  two 
  other 
  British 
  forms, 
  slightly 
  

   differing 
  from 
  H. 
  sparsa 
  in 
  the 
  shape 
  of 
  the 
  dorsal 
  plate 
  and 
  

   inferior 
  appendages. 
  Although 
  I 
  have 
  four 
  examples 
  of 
  

   each 
  form, 
  in 
  none 
  of 
  them 
  are 
  the 
  scent-organs 
  everted. 
  

   I 
  am 
  therefore 
  deferring 
  their 
  description 
  until 
  more 
  

   material 
  comes 
  to 
  hand. 
  

  

  I 
  am 
  indebted 
  to 
  Dr. 
  H. 
  Eltringham, 
  who 
  kindly 
  made 
  

   the 
  drawings 
  for 
  the 
  accompanying 
  plate. 
  

  

  Explanation 
  of 
  Plate 
  XVII. 
  

  

  