MK.  J.  O.  WESTWOOD  ON  NYCTERIBIA. 
287 
tremity,  especially  at  the  sides ;  and  the  abdomen  is  terminated  by  a  distinct  and  con- 
siderably narrower  segment,  notched  at  the  tip,  as  tliough  formed  of  two  united  incras- 
sated  styles,  having  moreover,  as  it  were,  a  raised  longitudinal  lobe  along  its  centre. 
On  the  under  side  the  basal  segment  is,  as  usual,  very  distinct  and  ciliated  ;  then  fol- 
lows a  large  and  nearly  square  region,  (corresponding  with  the  superior  pilose  portion,) 
having  three  transverse  series  of  hairs,  of  which  the  last  is  the  most  distinct :  this  is 
succeeded  by  a  transverse  region  similarly  terminated,  which  is  again  followed  by  a 
lunate  and  ciliated  portion,  and  the  last  segment  is  channelled  down  the  middle.  This 
insect  must  be  regarded  as  a  female,  (its  specific  identity  with  the  former  being  unques- 
tionable,) notwithstanding  that,  from  the  existence  and  situation  of  the  several  trans- 
verse series  of  hairs,  no  less  than  seven  segments  are  indicated  on  the  under  side. 
Two  of  the  specimens  of  this  species  in  the  British  Museum  are  males ;  the  third  is  a 
female,  and  exhibits  more  strongly  the  curious  trilobed  structure  of  the  terminal  seg- 
ment of  the  abdomen. 
Mr.  Stephens's  specimens  of  the  species  described  by  Montagu,  and  named  Her- 
manni  by  Dr.  Leach,  are  of  one  sex,  and  very  differently  constructed  from  any  of  the 
preceding  insects  ;  and  I  regret  that  their  dried  and  shrivelled  state  prevents  my  so 
completely  ascertaining  their  structure  as  I  could  have  wished.  The  basal  segment  of 
the  abdomen  is  much  produced  above  and  at  the  sides,  but  it  does  not  appear  to  me  to 
overlap  any  of  the  following  segments,  two  of  which  immediately  succeed,  and  are  very 
short ;  the  terminal  fourth  joint  is  large,  semi-ovate,  and  from  beneath  its  sides,  at 
the  extremity,  arise  two  porrected  styles,  furnished  at  the  tip  with  strong  bristles. 
On  the  under  side  the  basal  segment  is  reduced  to  its  ordinary  and  ciliated  form  and 
size  ;  then  follow  two  short  segments  corresponding  with  those  on  the  upper  side ; 
which  are  succeeded  by  a  large  segment  corresponding  with  the  terminal  superior 
one  ;  and  between  the  inferior  margins  of  the  latter  and  the  extremity  of  the  former  is 
protruded  a  distinct  and  convex  segment,  having  its  upper  margins  armed  with  the  two 
porrected  styles  above  mentioned.  1  could  not,  however,  distinguish  any  traces  of  a 
central  lobe  or  style. 
This  description  accords  with  Dr.  Leach's  characters  of  Nycteribia  given  above.  Of 
Dr.  Leach's  three  specimens  of  this  species  in  the  British  Museum,  two  (as  well  as  the 
specimen  received  by  him  from  Bonelli)  are  of  the  same  styliferous  sex  as  Mr.  Stephens's  : 
but  the  other  British  specimen  is,  fortunately,  of  the  opposite  sex.  It  is,  however, 
in  too  shrivelled  a  state  to  allow  me  to  give  a  more  minute  description  of  its  abdomen 
than  that  it  is  more  robust  than  in  the  styliferous  specimens,  that  its  upper  side  exhibits 
four  or  five  articulations,  and  that  its  extremity  beneath  is  distinctly  furnished  with  two 
incurved  styles  closely  applied  along  the  under  surface  of  the  terminal  joint.  These  two 
organs,  hitherto  unnoticed  by  the  describers  of  this  species,  thus  clearly  indicate  the 
male  sex,  confirming  the  opinion  of  Dr.  Leach,  and  proving  that  the  female  is  organized, 
