341 
38.  Siphoniulus  albus  sp.  n.  Pl.  XIX,  fig.  13  — 13a. 
Sumatra:  Manindjau.  A  single  immature  9  specimen. 
Colour  (in  alcohol,  of  young)  entirely  white. 
Head  longer  than  the  rostrum;  rostrum  broad  at  the  base  pointed 
apically.  Antennae  much  longer  than  rostrum. 
Segments  smooth,  not  hairy,  the  1st  smaller  than  the  2*a,  with 
rounded  inferior  border.  The  rest  finely  striate  longitudinally,  and 
furnished  with  a  transverse  sulcus.  Pores  conspicuous,  situated  about 
halfway  up  the  side  of  the  segments.  Anal  segment  annular,  without 
a  caudal  process. 
Number  of  segments  51. 
Length  about  11  mm. 
Sub-order  CHORDEUMOIDEA ,  Cook  and  Collins  ■). 
Family  CHORDEUMIDAE. 
Sub-family  HeterochordeuminaB  nov. 
I  propose  this  new  sub-family  for  the  reception  of  the  peculiar  genus 
Heterochordeuma  which  differs  from  all  the  known  European  genera 
and  so  far  as  I  am  aware  from  all  those  that  have  been  described 
from  N.-America  -  which  may  be  collectively  referred  to  the  sub- 
family Chordeuminae  -  in  possessing  32  body  segments,  each  of  which, 
excepting  the  first  and  last,  is  provided  with  a  wide  depressed  keel  which 
bears  only  one  setiferous  tubercle,  the  remaining  two  being  situated 
close  together  near  the  summit  of  the  dorsum.  In  one  European  genus, 
Atractosoma,  which  is  also  a  strongly  keeled  form,  two  of  the  seti- 
ferous tubercles  are  situated  upon  the  keels.  This  difference,  however, 
is  perhaps  not  more  than  of  generic  value. 
Heterochordeuma ,  Pocock. 
Ann.  Mus.  Genov.  (2),  XIII,  p.  387. 
Head  prominent  vertex  high,  labral  region  strongly  receding,  labral 
emargination  tridentate;  a  cluster  of  ocelli  on  each  side.  Antennae 
widely  separated,  elongate,  the  third  segment  the  longest.  Basal 
1)  Daring  a  recent  visit  to  the  British  Museum,  Messrs.  Cook  and  Collins,  who 
are  doing  some  admirable  work  upon  the  Diplopoda,  informed  me  that  they  propose 
to  elevate  the  Millipedes  of  the  Chordeumid  group  to  the  rank  of  a  sub-order  equi- 
valent to  my  Polydesmoidea.  I  entirely  agree  with  the  proposition. 
