NO.    5      MALE  GENITALIA  OF  ORTHOPTEROID  INSECTS — SNODGRASS        I7 
turned  to  the  right  and  its  apex  bent  to  the  left  beneath  the  abdomen 
of  the  female  (see  figure  by  Friederichs).  In  the  case  of  Monotylota 
ramhnri  the  male  grasps  the  fore  part  of  the  head  of  the  female  with 
his  mandibles,  curves  his  body  to  the  right  of  the  female,  still  holding 
the  latter  by  the  head,  and  directs  the  end  of  his  abdomen  to  the  left 
beneath  that  of  the  female  to  effect  a  union  of  the  genital  parts. 
The  genital  region  of  the  female  (fig.  4  B,  C)  is  entirely  unarmed. 
The  gonotreme  {Gtr)  opens  into  a  tubular  genital  chamber  above  the 
eighth  sternum,  which  is  continuous  with  the  short  median  oviduct 
anteriorly,  and  has  the  aperture  of  the  spermatheca  in  its  dorsal  wall 
just  within  the  gonotreme.  The  male  organs,  therefore,  are  probably 
inserted  into  the  genital  chamber  of  the  female  in  order  to  expose 
the  mouth  of  the  spermatheca.  The  presence  of  compound  accessory 
glands  in  the  male  (fig.  4  A)  would  suggest  the  formation  of  a 
spermatophore,  and  Friederichs  records  that  a  male  was  observed  a 
few  minutes  after  copulation  to  double  upon  himself  and  eat  some- 
thing (possible  a  spermatophore)  projecting  from  his  genital  open- 
ing. Copulation  with  Monotylota  ramhnri,  Friederichs  says,  lasts 
about  15  minutes. 
The  question  of  the  relationships  of  the  Embiidae  has  given  rise 
to  mvtch  discussion,  some  writers  holding  that  the  embiids  have  affini- 
ties with  the  Plecoptera  and  others  that  they  are  related  to  the  Isop- 
tera.  The  structure  of  the  internal  genital  organs  of  the  male  shows 
definitely  that  the  Embiidae  belong  to  the  orthopteroid  group  of  insects 
and  not  to  the  Plecoptera,  but  the  embiids  lack  some  of  the  character- 
istic features  of  the  termites.  The  eighth  abdominal  sternum  of  the 
female,  for  example,  is  a  well-developed  external  plate  (fig.  4  B,  C, 
VI IIS),  and  the  genital  opening  {Gtr)  is  exposed  behind  it.  Styli 
are  never  present  on  the  ninth  sternum  of  the  male.  On  the  other 
hand,  the  tenth  tergum  forms  the  apical  dorsal  plate  of  the  abdomen 
(B,  XT),  as  in  Isoptera  and  Blattidae,  and  the  epiproct  is  a  rudi- 
mentary lobe,  present  in  the  female  (C,  Eppt),  on  its  ventral  surface. 
That  the  accessory  genitalia  of  the  male  have  been  developed  within 
the  Eml)iidae  is  apparent  from  the  relatively  simple  terminal  parts 
in  the  primitive  genus  ClotJwda. 
IV.   ZORAPTERA 
The  Zoraptera  are  here  included  with  the  orthopteroid  insects,  not 
implying  that  their  relations  to  the  Orthoptera  can  be  demonstrated, 
but  because  the  insects  cannot  be  satisfactorily  placed  anywhere  else. 
Crampton  (1922)  expressed  the  opinion  that  psocids,  Zoraptera,  and 
embiids  have  been  derived  from  a  common  ancestral  source,  and 
