352 
6th  becoming  very  gradually  directed  more  and  more  backwards  with 
anterior  border  very  lightly  convex,  and  posterior  border  straight; 
the  lateral  margin  more  or  less  strongly  excised,  the  anterior  angle 
either  sharp  or  rounded ,  the  posterior  angle  rounded,  either  one  or  two 
smaller  teeth  between  them.  The  dorsal  surface  almost  smooth,  only 
very  weakly  granular,  with  a  row  of  tubercles  only  at  the  pos- 
terior end  of  the  body.  The  pores  close  to  the  emarginated  border. 
Caudal  process  with  parallel  sides,  rounded  lobate  posterior  border.  Lat- 
eral surface  smooth;  sternal  surfaces  not  spinous  and  only  lightly  sulcate. 
Copulatory  foot  stout,  the  inferior  terminal  flagellum  curving  di- 
rectly upwards  and  backwards,  the  superior  inwards  and  backwards. 
Length  52  mm. ,  width  of  10th  9,  0f  2**  7.5 ,  of  l*t  5.7,  length  of  1«*  2.7. 
Two  male  specimens  were  obtained.  One  of  these  represented  by 
only  the  anterior  half  of  the  body x)  is  coloured  as  described  above.  The 
other,  a  complete  specimen,  is  testaceous  throughout  and  had  no  doubt 
moulted  only  a  short  time  before  its  capture. 
47.  Platyrhachus  subspinosus,  sp.  n.  Pl.  XIX,  fig.  19  — 19». 
Sumatra:  Padang. 
Colour  reddish  brown;  keels,  legs,  sterna,  caudal  process  and  an- 
tennas, except  the  two  apical  segments,  flavous  ;  a  fuscous  spot  on  the 
middle  of  the  anterior  half  of  the  somites. 
Head  and  antennœ  normal. 
First  tergite  convex  from  side  to  side,  the  anterior  border  lightly 
convex  at  the  sides  and  sloping  gradually  backwards  and  outwards 
to  the  lateral  angle ,  the  posterior  border  sloping  more  abruptly  for- 
wards to  the  same  angle,  a  shallow  furrow  before  the  anterior  border 
which  is  furnished  with  a  row  of  close-set  small  tubercles.  Second 
tergite  with  its  keel  depressed  below  the  angle  of  the  first  and  the 
keel  of  the  second.  The  keels  of  the  third  and  fourth  directed  forwards 
and  downwards,  with  their  anterior  angles  rounded  but  acute  and 
their  posterior  angles  sharper  but  obtuse,  lateral  border  very  lightly 
lobulate.  The  keels  from  the  fifth  to  the  twelfth  projecting  nearly  at  right 
angles,  the  rest  becoming  gradually  more  and  more  directed  back- 
wards, the  anterior  border  with  a  small  but  distinct  basal  shoulder, 
nearly  straight  but  perhaps  very  lightly  convex,  the  anterior  angle  a 
1)  Tho  colouring  of  the  posterior  half  of  the  body  in  fig.  9,  thorefore,  is  guess-work. 
