45 
The  setae  have  the  usual  shape;  the  superior  pairs  are  situated 
quite  dorsally,  the  inferior  ones  at  the  ventral  side  of  the  body.  In 
the  anterior  segments  the  setae  of  each  couple  are  separated  by  a 
rather  large  distance,  in  the  posterior  segments  they  come  nearer 
one  to  another  and  are  situated  at  the  edges  of  the  quadrangular  body. 
The  cl  it  ell  urn  is  characterized  by  a  narrow,  folded  ridge  along 
segment  (XIX)  XX -XXV,  situated  dorsally  of  the  ventral  series  of 
setae;  the  structure  of  the  clitellum  shows  the  same  glandular  ele- 
ments as  in  Glyphidrilus,  it  is  only  distinguished  by  its  richness  of 
bloodvessels.  There  are  no  copulatory  papillae,  and  the  external  genital 
pores  are  not  visible. 
On  transverse  sections  it  could  be  stated,  that  the  va  sa  defe- 
rentia  open  outwards  in  the  groove  between  segment  XXI 
and  XXII,  just  in  the  series  of  the  superior  setae  of  the  ven- 
tral couple;  a  prostate-gland  appears  not  to  be  present.  Three 
pairs  of  seminal  vesicles  are  situated  in  segment  IX— XII.  Several 
small  spermathecae  lie  in  segment  XIV,  XV  and  XVI;  in 
segment  XIV  there  are  four  pairs  of  them,  one  pouch  situated 
next  to  each  seta.  The  following  segment  shows  five  pairs  of  them; 
besides  the  four  pairs  of  the  preceding  segment,  it  possesses  another 
one  in  the  lateral  field.  In  the  XVIth  segment  only  two  pairs  of  sper- 
mathecae are  present,  situated  next  to  the  setae  of  the  ventral  pair. 
The  epithelium  lining  the  pouch  consists  of  tall  columnar  cells,  except 
at  its  median  side,  where  the  cells  are  much  lower  and  flatter  like  those 
in  Glyphidrilus.  All  spermathecae  are  densely  filled  with  spermatozoa. 
Nephridia  are  present,  except  in  the  anterior  twelve  segments. 
The  gizzard  lies  in  segment  VIII.  The  intestinal  canal  of  some  specimens 
contained  a  large  quantity  of  diatomaceae  ;  it  may  therefore  be  con- 
cluded ,  that  the  worm  lives  in  the  soil  below  the  water.  The  number 
of  earthworms  having  this  manner  of  life  is  rather  small;  besides 
Criodrilus,  Allurus  and  Glyphidrilus,  as  stated  above,  two  species 
of  Acanthodrilus ,  Ac.  dalei  and  Ac.  georgianus  do  also  belong  to  it, 
according  to  Mr.  Beddard's  statement 1). 
Though  this  worm  agrees  in  its  external  appearance  much  with 
Glyphidrilus  Weberi,  it  cannot  be  ranged  in  the  same  genus,  as 
its  male  pores  are  not  situated  on  the  same  segments  as  in  Glyphi- 
I)  Proc.  R.  Ph.  Soc.  Edinburgh,  1891,  p.  208. 
