40 
lum,  without  projecting  beyond  its  surface;  their  transverse  and  longi- 
tudinal diameter  is  about  0.24  mm.  For  the  greater  part  they  consist 
of  slender,  filamentous  elements,  each  of  them  with  an  elongated, 
narrow  nucleus  ;  those  nuclei  form  a  continuous  series  with  the  nuclei 
of  the  hypodermis-cells,  but  they  lie  a  little  below  the  plane  of  them. 
It  may  be  suggested,  that  these  elements  bear  tactile  hairs  upon  their  tip , 
as  stated  with  the  sensory  organs  of  other  Oligochaetae ,  but  I  have 
not  observed  them.  In  the  basal  portion  of  the  organ  other  club-shaped 
cells  are  to  be  found,  traversing  with  their  elongated,  narrow  necks 
the  layer  of  filamentous  cells  ;  they  consist  of  a  finely  granular  sub- 
stance and  possess  an  oval  nucleus. 
Similar  organs  are  already  met  with  in  other  Lumbricidae.  Michaelsen 
found  in  Ac.  georgianus  *)  upon  the  Xth  segment,  two  large  papillae  in 
the  series  of  the  ventral  bristles.  He  describes  them  as  clear,  eye-ball- 
shaped  organs,  which  lie  between  the  layer  of  transverse  muscles  and 
the  cuticula  and  consist  of  slender,  spindle-shaped  cells.  The  sin- 
neszonen,  observed  by  Vejdowsky  in  the  segments  of  the  middle 
body-region  of  some  Lumbriculidae ,  seem  also  much  to  resemble 
the  organs  of  G-lyphidrilus  ;  those  organs  however  appear  to  be  extra  - 
dible.  Probably  the  glandular  papillae,  of  which  Rosa  observed  no  less 
than  22  in  Bilimba  papillata,  belong  to  the  same  category. 
The  intestinal  canal  of  this  worm  is  of  a  simple  structure 
and  wants  the  glandular  coeca,  found  in  many  other  Lumbricidae. 
The  pharynx  is  situated  in  segment  IV;  then  follows  the  oesophagus 
in  segments  V  to  VII,  which  in  the  VIII th  segment  passes  into  the 
gizzard.  The  tubular  intestine ,  then  following ,  extends  back  to  segment 
XV,  where  it  passes  into  the  sacculated  intestine.  A  kind  of  typhlo- 
solis  appears  to  be  present  in  segment  XIX  and  XX;  singular  lon- 
gitudinal folds  also  are  to  be  seen  here  at  the  ventral  side  of  the 
intestine. 
The  epithelium,  lining  the  innerside  of  the  pharynx,  has  not  the 
same  structure  on  the  dorsal  and  the  ventral  side.  In  the  first  region 
it  consists  of  tall  columnar  cells,  provided  with  cilia  and  showing 
darkly  stained  nuclei,  but  in  the  lateral  region  the  epithelium  alters 
its  character  and  becomes  a  layer ,  showing  no  distinct  cells ,  but 
only  a  small  number  of  irregularly  scattered  nuclei.  The  outer  wall  of 
1)  Jahrb.  der  Wissensch.  Anstalten  zu  Hamburg.  V,  1888,  p.  70,  pl.  2,  fig.  id. 
