NO.    5      MALE  GENITALIA  OF  ORTHOPTEROID  INSECTS — SNODGRASS        29 
each  other  distally  (A,  B,  Cer)  ;  each  cercus,  moreover,  has  a  mesal 
lobe  arising  from  its  base  (a^  b),  the  left  one  of  which  is  a  small  re- 
curved process  (B,  a),  the  right  (A,  B,  b)  a  large  irregular  lobe  larger 
than  the  cercus  itself. 
The  females  of  most  Phasmatidae,  including  Timema,  have  a  small 
though  fully  developed  ovipositor  consisting  of  the  usual  three  pairs 
of  valvulae.  The  valvulae  are  weak  and  flexible,  and  enclose  between 
them  a  cavity  the  size  of  an  individual  egg.  The  ovipositor  is  mostly 
concealed  by  the  long  subgenital  eighth  abdominal  sternum,  which 
forms  the  floor  of  an  ample  genital  chamber  extending  anterior  to 
the  base  of  the  ovipositor.  The  opening  of  the  oviduct  is  a  median 
cleft  in  the  genital  chamber  floor  below  the  base  of  the  ovipositor,  and 
the  spermathecal  opening  is  a  small  aperture  in  the  dorsal  wall  of  the 
chamber  just  anterior  to  the  bases  of  the  first  valvulae  (fig.  7  D, 
Spr).  The  sperm  receptacle  of  Diapheronicra  fcmorata  consists  of 
two  small  spermathecal  sacs  (E)  with  convoluted  ducts  opening 
through  the  common  exit.  Each  sac  is  a  thick-walled  structure  having 
a  tubular  lumen  connected  with  the  duct  near  its  anterior  end  (F). 
The  histology  of  the  spermathecae  has  been  described  by  Marshall 
and  Severin  (1906). 
During  mating  the  male  takes  a  position  on  the  female's  back  and 
curves  his  abdomen  downward  and  forward  beneath  that  of  the  female 
(see  Stockard,  1908;  Grimpe,  1921).  The  exact  use  of  the  copulatory 
apparatus  has  not  been  recorded,  and  no  observations  suggest  that  the 
phasmatids  produce  spermatophores.  Parthenogenesis  is  of  common 
occurrence  in  the  family.  Each  egg  may  be  held  for  some  time  in  the 
ovipositor  before  being  liberated.  Ordinarily  the  eggs  are  dropped 
casually,  but  according  to  Grimpe  (1921),  the  female  of  Phyllium 
bioculafum  by  a  strong  swing  of  the  abdomen  throws  each  egg  a 
considerable  distance  from  her. 
VII.    MANTOIDEA 
The  male  genitalia  of  the  mantids  are  very  similar  in  general 
structure  to  those  of  Blatta  and  Periplaneta  among  the  Blattidae, 
and  differ  but  little  among  the  mantid  genera.  In  Tcnodera  sinetisis, 
the  species  here  illustrated  (fig.  10),  the  slender  male  abdomen  tapers 
to  the  apex  of  the  slightly  asymmetrical  sternum  of  the  ninth  segment 
(A,  IXS),  which  bears  two  small  terminal  styli  (Sty),  and  projects 
far  beyond  the  cercus-bearing  proctiger  composed  of  the  tenth  and 
eleventh  segments.  Resting  in  the  shallow  cavity  on  the  dorsal  side  of 
the  large  ninth  sternum,  fully  exposed  beyond  the  proctiger,  are  the 
