NO.    5      MALE  GENITALIA  OF  ORTHOPTEROID  INSECTS — SNODGRASS        99 
long  phallotreme  cleft  (C).  Its  lateral  walls  contain  a  pair  of  large 
plates  (u),  from  each  of  which  a  slender  sclerotic  bar  (s,  q)  is 
continued  through  the  wall  of  the  meatus,  and  may  terminate  in  a 
free  apical  process  (p).   A  second  pair  of  anterior  (or  dorsolateral) 
Fig.    42.- 
genitalia. 
Acridoidea-Acrididac :      nymphal    development    of    external    male 
A,  Dissosfeira  Carolina  (Linnaeus),  end  of  abdomen  of  nj'mph  with  wings 
just  differentiated  from  tergal  plate.  B,  same,  phallic  lobes,  connected  by  short 
ejaculatory  duct  with  mesodermal  ampullae  of  vasa  deferentia.  C,  Mclanoplus 
mexicanus  (Saussure),  phallus  of  nymph  with  wings  not  extending  beyond 
metatergum,  dorsal  view.  D,  same,  nymph  with  wings  reaching  to  middle  of 
first  abdominal  tergum,  phallus  in  genital  chamber  beneath  outer  cuticula,  dorsal 
view.  E,  same,  ventral  view,  showing  endophallic  sac.  F,  same,  end  of  abdomen 
of  nymph  with  wings  extending  to  middle  of  third  abdominal  tergum.  G,  same, 
diagrammatic  section  of  end  of  abdomen  of  F.  H,  same,  phallus  of  nymph  in 
stage  of  F,  dorsal  view.     I,  same,  mature  phallus,  dorsal  view. 
For  letter  explanation,  see  fig.  41. 
bars  in  the  meatus  wall  (C,  o),  united  basally  by  a  dorsal  bridge  (0. 
runs  out  into  the  anterior  apical  processes  (m).  Further  details  of 
the  structure  of  the  coinplex  phallic  organ  of  the  Acrididae,  its  muscu- 
lature and  mechanism,  and  its  variations  in  the  several  acridid  sub- 
families the  writer  has  described  in  a  former  paper  (1935). 
