350 
anterior  angle  of  all  convex,  rectangularly  convex  anteriorly,  obtusely 
convex  posteriorly;  the  posterior  angle  a  right  angle  anteriorly,  beco- 
ming more  and  more  acute  posteriorly;  the  external  and  anterior 
margins  lightly  convex,  the  former  not  dentate,  but  slender  and 
very  feebly  quadrilobate.  The  upper  surface  of  the  somites  closely  and 
finely,  but  not  sharply  granular  throughout,  with  a  series  of  larger 
granules  along  the  hinder  border,  and  with  indistinct  traces  of  two 
anterior  transverse  series,  these  last  series  being  more  pronounced 
posteriorly.  The  pores  situated  about  \  a  mm.  from  the  lateral  border. 
The  caudal  process  with  convex  obsoletely  lobate  posterior  border  and 
slightly  converging  sides.  The  lateral  surface  of  the  keel-bearing  half 
of  the  segments  somewhat  coarsely  granular.  The  sternal  surface  not 
spined,  emarginate  behind  and  in  front,  transversely  impressed  above; 
anal  sternite  bi-tuberculate.  The  cylindrical  portion  of  the  somites 
exceedingly  closely  punctulate  throughout. 
Legs  normal. 
tf.  A  little  narrower,  a  little  flatter,  keels  a  little  larger,  with 
margins  more  distinctly  lobate. 
Copulatory  foot  with  its  distal  segment  consisting  of  a  proximally 
hairy,  distally  smooth  and  tapering  piece,  which  terminates  in  two 
slender,  pointed,  curved  processes,  whereof  the  external  is  more 
curved  than  the  internal. 
Length  about  72  mm.;  width  (across  keels)  of  10th  somite  10.5  mm.; 
of  1st  7.5,  of  2*d  9;  length  of  1st  3. 
45.  Platyrhachus  xanthopus ,  sp.  n.  Pl.  XIX,  fig.  11— 18a. 
Sumatra:  Manindjau  and  Paningahan. 
9.  Robust,  attenuated  anteriorly. 
Colour  chocolate  brown  to  nearly  black  above;  antennae,  legs  and 
keels  flavous;  the  caudal  process  almost  entirely  flavous. 
First  tergite  about  as  wide  as  the  head ,  lightly  convex  above ,  scarcely 
keeled,  the  lateral  border  merely  being  produced  into  an  angle,  beset  with 
larger  and  smaller,  low,  rounded  granules,  a  series  of  larger  granules 
along  the  anterior  border,  the  anterior  and  posterior  borders  straight 
in  the  middle,  convex  at  the  sides  and  converging  to  the  lateral 
angle;  transverse  impression  in  front  of  the  anterior  border.  The  keels 
of  the  2»*,  3rd  and  4^  produced  obliquely  forwards  and  depressed; 
keels  of  the  rest  of  the  segments  situated  above  the  middle  of  the 
