NO.    5      MALE  GENITALIA  OF  ORTHOPTEROID  INSECTS — SNODGRASS        93 
structure.  As  exposed  by  depressing  the  ninth  sternum  (fig.  38  B), 
the  phallus  appears  as  a  large,  rounded,  thick-lipped,  membranous 
fold  (vl)  with  a  concave  upper  surface  that  leads  into  a  deep  pouch 
above  it.  There  is  no  epiphallic  sclerotization,  and  the  dorsal  lip  of  the 
pouch  is  reflected  directly  into  the  dorsal  v^^all  of  the  genital  chamber 
(^r-x),  but  on  it  there  opens  a  long,  median,  tubular  phallic  gland 
(figs.  38  B,  39  A,  PJiGld).  From  just  within  the  dorsal  lip  of  the 
phallic  pouch  a  strong,  median,  flattened,  bilobed  process  (fig.  38  B, 
cc)  projects  downward  from  the  dorsal  wall,  in  which  it  is  supported 
by  a  wide,  transverse  sclerite  (B,  C,  dd).  This  sclerite  and  its  median 
process  are  termed  the  "  ancre "  by  De  Saussure  and  Zehntner 
(1894)  ;  Walker  (1922)  regards  it  as  the  "  pseudosternite  "  (epiphal- 
lus),  but  its  shape  in  Scapteriscus  (E)  suggests  rather  a  homology 
with  the  guide  of  the  spermatophore  duct  in  Gryllus.  Concealed  in 
front  of  the  median  process,  when  viewed  from  behind,  and  closely 
appressed  to  its  anterior  surface,  is  a  pair  of  peglike  processes  (C,  ee) 
supported  on  a  second  and  smaller  plate  (j^)  in  the  dorsal  wall  of  the 
phallic  cavity.  These  processes  are  the  "  titillators  "  of  De  Saussure 
and  Zehntner  ;  they  are  generally  longer  and  slenderer  than  in  G.  hexa- 
dactyla  (G).  Anterior  to  the  second  sclerite  the  dorsal  wall  of  the 
phallic  pouch  presents  a  median  depression,  and  the  ejaculatory  duct 
opens  directly  into  the  anterior  end  of  the  pouch. 
In  Scapteriscus  vicinus  the  phallus  is  similar  to  that  of  Gryllotalpa, 
but  the  dorsal  armature  of  the  phallic  pouch  is  quite  different.  The 
median,  posterior  process  here  has  the  form  of  a  large,  descendant, 
but  abruptly  elbowed  arm  (E,  F,  cc)  ending  in  a  sclerotic  knob,  and 
is  contained  in  a  membranous  fold  (w)  of  the  dorsal  wall  of  the  pouch. 
This  process  would  thus  appear  to  represent  the  median  rod  or  lobe  of 
Gryllidae  (figs.  32  D,  36  C,  v)  that  holds  the  end  of  the  spermatophore 
duct.  Its  base  is  supported  by  an  H -shaped  sclerite  in  the  dorsal  wall 
of  the  phallic  pouch  (fig.  38  D,  F,  dd),  just  behind  the  cross-bar  of 
which  opens  ventrally  a  long,  tubular  phallic  gland  (D,  E,  PhGld) 
similar  to  that  of  Gryllotalpa.  The  anterior  dorsal  processes  of 
Scapteriscus  are  long  and  tapering  (G,  ce),  and  arise  from  separate 
basal  extensions  {ff)  in  the  pouch  wall. 
The  gryllotalpid  phallus  has  evidently  been  derived  from  an  organ 
having  the  gryllid  type  of  structure,  which  has  been  simplified  by 
the  union  of  the  dorsal  and  endophallic  cavities,  the  former  being 
represented  only  by  the  depression  of  the  dorsal  wall  of  the  common 
phallic  pouch.  The  separation  of  the  epiproct  from  the  tenth  tergum 
might  be  regarded  as  a  character  relating  the  mole  crickets  to  Stenopcl- 
matus,  but  the  phallic  structure  of  Stcnopclniatus  (fig.  31)  has  little 
in  common  with  that  of  Gryllotalpa  and  Scapteriscus. 
