69 
The  rows  of  b  r  i  s  1 1  e  s  are  very  noticeable  ;  there  are  about  40  setae 
upon  each  segment  in  a  continuous  row.  No  setae  present  upon  the 
clitellum.  The  internal  structure  resembles  that  of  other  Perichaeta- 
species;  the  seminal  vesiculae,  occupying  segment  X,  XI  and  XII, 
are  rather  highly  developed.  There  is  a  much  lobated  prostata ,  opening 
with  a  very  thick  excretory -duct  on  a  large  muscular  bulbus. 
Each  spermatheca  (Pl.  Ill,  fig.  29)  consists  of  a  rather  large,  glo- 
bular pouch ,  with  a  short ,  thick ,  muscular  duet ,  which  is  completely 
invested  with  nephridial  tubes,  and  of  a  single,  small  diverticulum, 
connected  with  the  main  pouch  by  a  coiled  duct.  The  examples  col- 
lected at  the  Mount  Singalang,  in  a  rather  indifferent  state  of  pre- 
servation, are  smaller  of  size,  about  80  mm.  in  length;  the  number 
of  setae  in  each  segment  appears  to  be  also  not  so  great  as  in  the 
foregoing,  30  à  36  in  a  row. 
A  large  incomplete  example,  from  Singkarah,  must  also  be  identified 
with  this  species. 
Among  the  „ species  dubiae"  of  Perichaeta,  collected  by  the  Sumatra- 
Expedition,  described  and  figured  by  my  self,  there  was  one  example , 
which  undoubtedly  belongs  to  this  species  1).  Though  we  know  other 
species  of  Perichaeta  from  the  Indo-malayan  region,  which  possess 
three  pairs  of  spermathecae ,  I  believe,  that  the  present  examples 
cannot  be  referred  to  one  of  them.  P.  birmanica  Rosa  2)  appears  to 
be  distinguished  by  a  greater  number  of  setae  upon  each  segment, 
as  well  as  by  the  shape  of  its  spermathecae  ;  P.  pegnana  Rosa  3),  P. 
carinensis  Rosa4)  and  P.  bournei5)  are  characterized  by  the  presence 
of  copulatory  papillae. 
17.  Perichaeta  sumatrana  Horst 6). 
Java:  Buitenzorg. 
Two  examples  from  Buitenzorg  probably  must  be  identified  with 
this  species.  There  are  no  copulatory  papillae.  The  number  of  setae  in 
the  segments  in  front  of  and  behind  the  clitellum  amounts  to  40  à  44. 
Two  pairs  of  spermathecae  are  present  in  segment  VIII  and  IX  ;  each 
1)  Reizen  en  Onderz.  d.  Sumatra-Expeditie,  Vermes,  p.  7,  Pl.  I,  fig.  5. 
2)  Ann.  Mus.  Civ.  Stor.  Nat.  Genova,  2d  Ser.,  Vol.  VI,  1888,  p.  164,  PL  III,  figs.  7—9. 
3)  id.     id.  Vol.  X,  1890,  p.  113,  Pl.  I,  figs.  6—8. 
4)  id.     id.  p.  107,  Pl.  I,  figs.  1  and  2. 
5)  id.     id.  p.  110,  Pl.  1,  figs.  3—5. 
6)  Reizen  en  Onderz.  d.  Sumatra-Expeditie,  Vermes,  p.  5,  Pl.  I,  fig.  2a  and  b. 
