359 
these  is  very  generally  a  process,  bifid  or  not,  upon  the  anterior  half 
of  the  sternum  of  the  5«*  segment. 
Synopsis  of  the  species. 
a.  Keels  very  small,  defined  above  merely  by  a  groove  and  without 
a  spiniform  posterior  angle.  (Groove  between  the  two  halves  of  the 
segments  beaded,  anal  sternite  convex  posteriorly)  .  .  .  subalbum. 
b.  Keels  large  or  small  but  shelf-like  with  acute  spiniform  hinder  angle. 
a1.  Keels  small  (as  in  Strongylosoma  of  authors). 
a2.  Lateral  margins  of  the  keels  denticulate,  the  dorsal  surface 
ornamented  with  an  anterior  and  a  posterior  marginal  row 
of  setiferous  granules;  groove  mentioned  above  not  sculptured 
pygmœum. 
b2.  Lateral  margins  of  keels  not  noticeably  denticulate  ;  without 
an  anterior  row  of  setiferous  granules;  groove  sculptured. 
a3.  A  row  of  setas  along  the  posterior  border  of  the  tergites  ; 
antennas  yellow  vinosum. 
b3.  "Without  a  row  of  set  as  along  the  posterior  border  of  the 
tergites:  antennas  black. 
a4.  Posterior  border  of  anal  sternite  truncate,  trilobed. 
a5.  Legs  entirely  flavous,  sculpturing  of  groove  weaker. 
afi.  A  wide  dorsal  flavous  band,  and  yellow  keels  .  . 
semi-carneum. 
ô6.  Body  entirely  rose  or  ruddy  red  ....  carneum. 
b5.  Distal  segments  of  legs  fuscous,  groove  sculptured 
into  sharply  defined  ridges  separated  by  a  distance 
equal  to  about  half  their  length  flavicoxis. 
54.  Tubercles  on  anal  sternite  long,  papilliform  far  surpas- 
sing the  edge  ;  sculpturing  of  groove  and  colouring  of  legs 
as  in  flavicoxis. 
a7.  Segments  black,  sternal  areas  deep  red,  apex  of 
keels  flavous  subnigrum. 
b7.  Sternal  areas  and  at  least  the  lower  part  of  the 
lateral  surface  flavous. 
a8.  Keels  flavous  only  at  the  tip,  the  three  distal 
segments  of  the  legs  fuscous  .  .  .  nigricorne. 
68.  Keels  entirely  flavous,  the  two  distal  leg- 
segments  fuscous  subflavum. 
