345 
b9.  Posterior  angle  of  the  keels  not  produced  into  a 
spiniform  process. 
a*K  Tail  quadrate;  the  upper  surface  of  the  keels 
horizontal   ,  subalbus. 
b11.  Tail  with  widely  rounded  posterior  border; 
upper  surface  of  the  keels  following  the  slope 
of  the  dorsum. 
a12.  Keels  directed  more  forwards  e.  g.  in  the 
17th  segment  the  anterior  angle  is  square 
and  the  posterior  does  not  project  beyond 
the  level  of  the  posterior  border  of  the  ter- 
gum  submissus. 
b12.  Keels  less  directed  forwards,  anterior  angle 
of  the  17th  obtuse  and  the  posterior  pro- 
jecting beyond  the  line  described  above .  . 
verrucosus, 
40.  Platyrhachus  humberti,  sp.  n.  Pl.  XIX,  fig.  15. 
Java:  Buitenzorg.  A  single  9  example.  ■ 
Body  narrowed  anteriorly  and  posteriorly. 
Colour;  head  and  segments  nearly  black,  antennae,  legs  and  keels 
fulvous;  foot-bearing  sternal  areas  paler  yellow. 
Head  thickly  granular. 
1st  tergite  granular,  with  a  row  of  tubercles  along  its  hinder  border, 
with  a  small  tubercular  keel  near  the  front  of  its  lateral  border.  The 
rest  of  the  segments  thickly  and  coarsely  granular  above,  with  a 
row  of  smooth  tubercules  along  the  posterior  border  of  each  and  two 
other  rows  of  tubercles  in  front  of  the  posterior  row;  these  rows  of 
tubercles  become  very  distinct  at  the  hinder  end  of  the  body.  Keels 
moderately  large ,  rising  just  above  the  middle  of  the  side,  horizontal, 
the  anterior  border  straight,  not  serrate,  and  with  a  prominent  basal 
shoulder,  the  anterior  angle  sharp  ;  the  lateral  border  for  the  most 
part  slightly  emarginate  irregularly  tubercular  or  dentate,  the  posterior 
angle  acute  and  considerably  produced  in  the  hinder  half  of  the  body, 
the  posterior  border  lightly  concave,  not  serrate;  the  keels  of  segments 
2-5  directed  forwards,  although  hardly  so  in  the  5th;  of  segments 
6  to  about  9  or  10  projecting  at  right  angles  to  the  long  axis  of  the 
body,  and  from  about  the  10th  to  the  end  of  the  body  projecting 
