36 
The  first  dorsal  pore  lies  in  the  intersegmental  groove  V/VI  or 
VI/VII  ;  on  the  clitellum  neither  pores  nor  intersegmental  grooves  are 
visible.  The  clitellum  occupies  segments  XIII  — XX,  the  first  of 
them  being  very  obvious.  The  prostate-pores  on  segment  XVII 
and  XIX ,  are  connected  on  each  side  by  a  longitudinal  oval  groove; 
both  grooves  are  surrounded  by  a  distinct  rectangular  area,  which  ap- 
pears somewhat  elevated  (Pl.  II.  fig.  11).  In  some  specimens  this  area 
was  interrupted  in  the  median  line.  The  space  between  the  ventral 
setae  of  the  posterior  clitellar  segments  looks  not  glandular. 
The  setae  are  arranged  in  four  couples;  they  have  the  ordinary 
shape  and  are  also  visible  on  the  clitellum.  The  distance  between  a 
dorsal  and  a  ventral  couple  is  about  equal  to  that  between  the  two 
ventral  couples. 
There  are  four  fascicles  of  penial  setae,  containing  each  a  couple 
of  them,  with  their  reserve-bristles.  The  setae  of  each  couple  have  a 
different  appearance  (Pl.  II.  fig.  12).  In  the  longer  one  the  distal 
extremity  is  ornamented  with  four  faint  thorny  processes  and  its  tip 
is  hook-shaped;  the  smaller  one  has  the  extremity  spoon-like  dilated. 
The  spermathecae  (Pl.  II.  fig.  13)  have  not  such  an  oblong  shape 
as  those  of  B.  floresiana;  they  too  are  divided  by  a  constriction  in  two 
compartments,  the  superior  of  which  bears  a  small  diverticulum. 
The  buccal  region  of  the  alimentary  canal  (in  front  of  the  cerebral 
ganglia)  is  furnished  dorsally  with  a  rather  broad,  flattened  diverticu- 
lum, lined  with  an  epithelium,  which  differs  from  the  epithelium  of 
the  remaining  portion  of  the  buccal  cavity;  its  cells  are  not  only 
broader  than  the  ordinary  buccal  cells,  but  contain  a  granular  proto- 
plasma,  giving  them  a  glandular  appearance.  The  cells  on  the  floor 
of  the  pouch  are  shorter  than  those  of  the  roof,  and  resemble  the 
glandular  cells  of  the  hypodermis. 
Michaelsen  already  observed  such  a  diverticulum  in  B.  Bolavi  *). 
This  pouch  is  not  to  be  confounded  with  a  diverticulum  of  the 
pharynx,  as  that  observed  by  Michaelsen  and  Beddard  in  several 
Acanthrodilus-species ,  and  recently  described  by  Benham  in  Emino- 
drilus  2)  ;  according  to  this  author's  observations  it  is  usually  ciliated 
in  its  dorsal  part. 
1)  Jahrb.  der  Hamburg.  Wissensch.  Anstalten,  VII,  1891,  p.  9. 
2)  Journ.  of  the  R.  Microsc  Society,  189],  p.  161,  pi.  3  and  4. 
