353 
right  angle  or,  posteriorly,  obtuse,  the  lateral  border  lightly  convex 
and  furnished  with  low,  rounded,  smooth  tubercles,  the  posterior 
angle  rectangular  or  posteriorly  acute  and  produced,  the  posterior 
border  straight  or  lightly  concave  and ,  like  the  anterior  border,  finely 
serrate.  The  pores  close  to  the  lateral  margin.  The  dorsal  surface  finely 
granular  throughout,  with  a  row  of  larger  granules  along  the  hinder 
border  and  two  rows ,  much  more  clearly  defined  at  the  posterior  end 
of  the  body,  anterior  to  the  last.  The  caudal  process  with  convex, 
lobulate  posterior  border.  The  lateral  surface  granular.  The  sternal 
surfaces  moderately  sulcate ,  with  a  spine  at  the  base  of  each  leg. 
Copulatory  foot  with  its  distal  third  directed  slightly  inwards,  the 
apex  ending  in  two  flagella,  the  inner  short,  lightly  curved,  and 
directed  forwards,  the  outer  longer  and  curved  forwards,  outwards 
and  upwards;  posterior  to  the  terminal  flagella  there  is  a  third  short 
process  on  the  upper  surface  of  the  appendage ,  directed  forwards  and 
slightly  upwards. 
Length  about  43  mm.;  width  of  10th  somite  6.5;  width  of  1st  4.7 
length  2.5. 
This  species  resembles  the  following  in  bearing  spines  on  the  sternal 
surfaces.  It  differs,  however,  slightly  in  colour,  in  having  more  robust 
keels,  with  posterior  angles  much  less  strongly  produced,  the  granu- 
lation coarser  and  in  the  different  form  of  the  copulatory  foot. 
48.  Platyrhachus  monticola,  sp.  n.  Pl.  XX,  fig.  10—  10b. 
Sumatra:  Mount  Singalang.  A  single  specimen. 
Colour;  head  and  tergites  reddish  brown,  the  head  being  paler  above  ; 
keels  and  legs  and  base  of  antennas  flavous. 
Head  and  antennœ  normal;  head  with  a  shallow  frontal  sulcus. 
First  tergite  nearly  flat  above,  very  convex  at  the  sides,  the  anterior 
and  posterior  borders  convex  at  the  sides  and  converging  to  form  the 
small  lateral  tuberculiform  keel.  The  keels  of  the  2nd ,  3^  and  4^  ter- 
gites projecting  forwards  and  downwards,  with  margins  sublobate. 
The  rest  of  the  keels  rather  small ,  depressed ,  following  the  slope  of 
the  back,  with  anterior  and  posterior  margins  finely  serrate.  Keels 
from  the  5«»  to  about  the  ll*  projecting  nearly  at  right  angles;  the 
rest  becoming  gradually  more  and  more  directed  backwards,  the  an- 
terior angle  obtuse  but  not  rounded,  the  lateral  edge  sharp  and  either 
