﻿192 
  

  

  HUBERT 
  M. 
  MORRIS. 
  

  

  The 
  cuticle 
  bears 
  many 
  small 
  scale-like 
  structures, 
  similar 
  to 
  those 
  of 
  Bibio 
  larvae, 
  

   each 
  being 
  provided 
  with 
  1-4 
  short 
  sharp-pointed 
  spines 
  (fig. 
  8). 
  Almost 
  all 
  

   the 
  scales 
  in 
  this 
  species 
  bear 
  spines, 
  whereas 
  in 
  Bibio 
  larvae 
  they 
  occur 
  only 
  on 
  the 
  

  

  Fig. 
  7. 
  Posterior 
  spiracle 
  of 
  larva 
  of 
  Dilophus 
  febrilis, 
  x 
  720. 
  

  

  larger 
  scales. 
  The 
  spines 
  on 
  the 
  scales 
  on 
  the 
  processes 
  are 
  longer 
  than 
  those 
  found 
  

   elsewhere, 
  and 
  2 
  appears 
  to 
  be 
  the 
  most 
  frequent 
  number 
  of 
  spines 
  on 
  each 
  scale 
  

   in 
  this 
  position 
  ; 
  the 
  number, 
  however, 
  varies 
  from 
  1-4. 
  In 
  addition 
  to 
  these 
  

   scales, 
  the 
  cuticle 
  bears 
  several 
  fairly 
  stout 
  and 
  moderate-sized 
  setae 
  dorsally 
  and 
  

   ventrally 
  on 
  each 
  segment. 
  

  

  Fig. 
  8. 
  Cuticle 
  of 
  larva 
  of 
  Dilophus 
  febrilis 
  

   from 
  dorsal 
  surface 
  of 
  fourth 
  segment, 
  

   showing 
  lateral 
  and 
  dorsal 
  views 
  ; 
  the 
  arrow 
  

   is 
  directed 
  anteriorly 
  ; 
  x 
  500. 
  

  

  The 
  alimentary 
  canal 
  (Plate 
  ix, 
  fig. 
  2) 
  of 
  Dilophus 
  febrilis 
  has 
  been 
  figured 
  by 
  

   Keilin 
  (1919). 
  It 
  is 
  almost 
  straight, 
  but 
  the 
  hind 
  gut 
  forms 
  a 
  loop 
  at 
  the 
  posterior 
  

   end 
  of 
  the 
  body. 
  It 
  has 
  three 
  anterior 
  caeca, 
  the 
  largest 
  of 
  which 
  is 
  ventral, 
  and 
  a 
  

  

  

  