64 
by  my-self  in  an  earlier  paper  and  drawn  up  after  a  single,  badly 
preserved  specimen,  collected  by  von  Horstook  at  the  Cape  of  Good 
Hope.  I  believe,  that  the  specimen  from  Java,  described  by  Rosa  as 
P.  operculata  J) ,  must  also  be  referred  to  this  species ,  for  it  agrees 
with  our  specimens  in  its  main  characters ,  specially  in  the  peculiar 
appearance  of  the  spermathecae. 
13.  Perichaeta  Houlleti  Perrier. 
(—  campanulata  Rosa). 
Sumatra:  Singkarah,  six  specimens. 
The  longest  example  measures  200  mm.  in  length.  The  appearance 
of  this  species  is  not  so  slender  as  that  of  P.  indica. 
The  circle  of  bristles  is  noticeable  by  its  white  colour.  The  clitellum 
shows  no  setae  nor  intersegmental  grooves  to  the  naked  eye.  There 
are  50  à  52  setae  in  the  segments  immediately  behind  the  clitellum  ; 
they  are  arranged  in  a  continuous  row.  Upon  segment  XVIII,  in  the 
space  between  the  male  generative  pores ,  12  setae  are  to  be  seen.  Those  of 
the  clitellum  have  a  bifid  extremity  and  the  rudimentary  appearance, 
first  observed  by  Beddard  2)  and  confirmed  by  Bourne3).  It  is 
proved  by  this  fact,  that  Bourne's  suggestion4),  „that  all  the  species 
of  one  genus  should  behave  in  the  same  way"  with  regard  to  the 
presence  or  absence  of  setae  is  entirely  erroneous;  for  in  adult  spe- 
cimens of  P.  indica,  I  never  observed  bristles  upon  the  clitellum, 
while  on  the  contrary  in  P.  affinis  they  are  present.  I  therefore  quite 
agree  with  Beddard,  that  this  is  a  characteristic  of  a  given  species, 
that  should  be  carefully  noted  5)  ;  for  it  is  difficult  enough  to  discri- 
minate the  numerous  species  of  Perichaeta.  I  will  not  deny  that  in 
young  examples  of  P.  indica  setae  probably  are  also  present  on  the 
clitellar  segments,  but  this  it  no  impediment  for  making  use  of  their 
total  absence  in  the  adult  worm  in  our  diagnosis.  Though  lion's  whelps 
have  a  spotted  skin  as  most  felidae ,  the  adult  animal  is  characterized 
by  the  absence  of  spots. 
The  cephalic  lobe  extends  over  half  the  buccal  segment;  the 
first  dorsal  pore  lies  in  the  intersegmental  groove  XI/XII. 
1)  Ann.  K.  K.  Naturh.  Hofmuseums,  Bd.  VI,  1891,  p.  398,  pl.  XIV,  figs.  6  and  6bis. 
2)  Proc.  Zool.  Society,  1887,  p.  389. 
3)  Journ.  Asiat,  Soc.  of  Bengal,  T.  LVIII,  1889,  p.  110. 
4)  Quartl.  Journ.  Micr.  Science,  T.  XXXII,  1891,  p.  54. 
5)  Proc.  Zool.  Soc,  1890,  p.  64. 
I 
