﻿502 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol.98 
  

  

  by 
  color; 
  both 
  are 
  brown 
  with 
  diceros 
  displaying 
  two 
  light 
  bands 
  on 
  

   the 
  pronotum 
  and 
  albescens 
  only 
  one 
  band. 
  >S'. 
  basalis 
  is 
  the 
  only 
  

   species 
  with 
  the 
  entire 
  venter 
  jet 
  black, 
  and 
  sometimes 
  the 
  entire 
  

   body 
  is 
  more 
  or 
  less 
  blackened. 
  S. 
  lutea, 
  substriata, 
  and 
  diminuta 
  

   are 
  the 
  only 
  forms 
  without 
  suprahumeral 
  horns. 
  S. 
  substriata 
  has 
  

   the 
  lateral 
  valves 
  produced 
  dorsally 
  beyond 
  the 
  pygofers 
  and 
  the 
  

   teeth 
  on 
  the 
  valves 
  are 
  very 
  thick, 
  while 
  lutea 
  and 
  diminuta 
  have 
  nor- 
  

   mal 
  lateral 
  valves 
  with 
  slender 
  teeth. 
  The 
  styles 
  in 
  lutea 
  are 
  smooth 
  

   beneath 
  apically 
  while 
  those 
  of 
  diminuta 
  are 
  serrate 
  beneath. 
  S. 
  

   brevicornis 
  and 
  curvata 
  have 
  the 
  suprahumeral 
  horns 
  very 
  minute 
  and 
  

   the 
  metopidium 
  is 
  evenly 
  convex 
  in 
  dorsal 
  aspect. 
  The 
  styles 
  in 
  

   brevicornis 
  are 
  evenly 
  curved 
  for 
  full 
  length, 
  while 
  those 
  of 
  curvata 
  

   are 
  abruptly 
  curved 
  in 
  the 
  apical 
  fourth. 
  The 
  teeth 
  on 
  the 
  lateral 
  

   valves 
  are 
  broadly 
  rounded 
  apically 
  in 
  brevicornis 
  and 
  apically 
  acute 
  

   in 
  curvata. 
  S. 
  palmeri 
  is 
  characterized 
  by 
  the 
  presence 
  of 
  a 
  basal 
  

   ring 
  on 
  the 
  posterior 
  arm 
  of 
  the 
  aedeagus. 
  S. 
  tauriniformis 
  is 
  the 
  

   only 
  species 
  with 
  the 
  teeth 
  of 
  the 
  lateral 
  valves 
  very 
  suddenly 
  nar- 
  

   rowed 
  and 
  stylate 
  in 
  the 
  apical 
  third. 
  S. 
  militaris 
  and 
  abnorma 
  are 
  

   unusual 
  in 
  the 
  elongate 
  form 
  of 
  the 
  genitalia; 
  the 
  sternal 
  plate 
  is 
  as 
  

   long 
  or 
  longer 
  than 
  the 
  rest 
  of 
  the 
  abdomen 
  in 
  either 
  species. 
  The 
  

   styles 
  in 
  abnorma 
  are 
  strongly 
  curved 
  in 
  the 
  apical 
  fourth, 
  while 
  in 
  

   militaris 
  they 
  are 
  straight 
  throughout. 
  S. 
  brevis, 
  brevitylus, 
  and 
  

   stimulea 
  have 
  in 
  common 
  a 
  strongly 
  convex 
  metopidium 
  with 
  the 
  

   suprahumeral 
  horns 
  continuing 
  the 
  line 
  of 
  the 
  metopidial 
  curve 
  and 
  

   projecting 
  somewhat 
  posteriorly. 
  In 
  brevis 
  the 
  teeth 
  of 
  the 
  lateral 
  

   valves 
  are 
  abruptly 
  bent 
  inward 
  in 
  the 
  apical 
  third 
  while 
  the 
  last 
  two 
  

   species 
  have 
  straight 
  teeth. 
  S. 
  stimulea 
  is 
  a 
  larger 
  species 
  than 
  

   brevitylus 
  and 
  has 
  the 
  functional 
  orifice 
  not 
  reaching 
  to 
  the 
  apex 
  of 
  

   the 
  aedeagus 
  while 
  brevitylus 
  has 
  a 
  functional 
  orifice 
  extending 
  to 
  

   the 
  apex 
  of 
  the 
  aedeagus. 
  S. 
  bubalus 
  is 
  the 
  largest 
  and 
  most 
  robust 
  

   species 
  of 
  the 
  genus 
  with 
  a 
  very 
  broad 
  metopidium. 
  Often 
  a 
  small 
  

   dark 
  spot 
  is 
  present 
  on 
  the 
  pronotum 
  near 
  the 
  apex 
  of 
  the 
  posterior 
  

   process 
  that 
  will 
  assist 
  in 
  distinguishing 
  bubalus 
  from 
  the 
  other 
  species. 
  

   S. 
  taurina 
  resembles 
  tauriniformis 
  in 
  that 
  both 
  forms 
  have 
  a 
  very 
  low 
  

   pronotum 
  with 
  the 
  suprahumeral 
  horns 
  relatively 
  short, 
  acute, 
  and 
  

   slightly 
  recurved 
  apically 
  ; 
  however, 
  the 
  teeth 
  of 
  the 
  lateral 
  valves 
  in 
  

   taurina 
  are 
  gradually 
  acute 
  apically 
  and 
  are 
  not 
  suddenly 
  narrowed 
  as 
  

   in 
  tauriniformis. 
  In 
  the 
  present 
  concept, 
  taurina 
  seems 
  to 
  be 
  a 
  com- 
  

   plex 
  of 
  at 
  least 
  two 
  variable 
  forms 
  between 
  which 
  this 
  Avriter 
  is 
  unable 
  

   to 
  distinguish. 
  If 
  taurina 
  represents 
  one 
  biological 
  unit, 
  then 
  it 
  is 
  

   subject 
  to 
  great 
  variation 
  thi*oughout 
  its 
  extensive 
  range. 
  S. 
  taurina, 
  

   as 
  characterized 
  by 
  Fitch's 
  type, 
  has 
  the 
  teeth 
  of 
  the 
  lateral 
  valves 
  

   very 
  acute 
  apically, 
  the 
  styles 
  evenly 
  curved 
  in 
  lateral 
  aspect 
  and 
  con- 
  

   vergent 
  in 
  the 
  apical 
  third 
  in 
  ventral 
  aspect. 
  The 
  extreme 
  of 
  the 
  other 
  

  

  