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SMITHSONIAN    MISCELLANEOUS    COLLECTIONS  VOL.    96 
usually  differentiated  into  an  irregular  basal  section  (B,  m)  and  a 
cylindrical  distal  part  (r),  and  is  cleft  posteriorly  (or  ventrally)  by 
the  long,  slitlike  phallotreme  (C,  Phtr),  which  may  involve  also  the 
distal  end,  and  thus  divide  the  apex  of  the  aedeagus  into  two  lateral 
terminal  lobes  (fig.  42  I,  r).    One  or  two  pairs  of  apical  processes 
XT  Eppt 
/'      ^    Papt  An  Pal 
iReofc 
bf  n~- 
,>Aed 
ejs^    DCS   /^  Dej 
Fig.  41. — Acridoidea-Acrididae :  structure  of  the  external  male  genitalia,  dia- 
grammatic (from  Snodgrass,  1935). 
A,  section  of  end  of  abdomen  somewhat  to  left  of  median  plane,  showing 
organs  within  genital  chamber  (GC),  and  those  invaginated  into  body  cavity. 
B,  distal  part  of  ectophallus  and  apodemal  arms.  C,  aedeagus  and  endophallus, 
basal  parts  of  phallus  removed. 
The  following  letter  explanations  apply  to  figs.  41  and  42:  a.  basal  part  of 
nymphal  phallus;  Aed,  aedeagus;  Amp,  mesodermal  ampulla;  An,  anus;  Apa, 
apodeme  of  aedeagus ;  b,  b,  terminal  lobes  of  nymphal  phallus ;  bf,_  basal  fold  of 
phallus;  c,  dorsal  depression  of  phallic  base;  Dej,  ductus  ejaculatorius ;  dl,  dorsal 
lobe  of  phallus;  ejs,  ejaculatory  sac;  Enph.  endophallus;  Epph,  epiphallus;  Ep{)t, 
epiproct;  GC,  genital  chamber;  IXSL,  subgenital  lobe  of  ninth  abdominal  ster- 
num; 7M,  basal  part  of  dorsal  lobe  of  phallus;  n,  dorsal  (anterior)  apical  process 
of  aedeagus ;  0,  dorsal  (anterior)  sclerite  of  phallotreme  wall ;  p,  ventral  (poste- 
rior) apical  process  of  aedeagus;  Pal,  pallium;  Pal',  inner  fold  of  phallium; 
Papt,  paraproct;  Plnn,  phallomere ;  Phtr,  phallotreme;  q,  ventral  (posterior) 
sclerite  of  phallotreme  wall ;  r,  distal  part  of  dorsal  lobe  of  phallus ;  Rect, 
rectum:  s,  arm  connecting  posterior  phallotreme  sclerite  (g)  with  endophallic 
plate  (?0  ;  sps,  spermatophore  sac  of  endophallus ;  t,  dorsal  bridge  of  dorsal 
phallotreme  sclerites ;  u,  lateral  plate  of  endophallus ;  Vd,  vas  deferens ;  vl,  ven- 
tral lobe  of  phallus;  x-x,  cut  edge  of  anterior  wall  of  genital  chamber;  X.V, 
venter  of  tenth  abdominal  segment;  y,  gonopore  process  of  endophallic  plate; 
z,  zygoma  of  aedeagal  apodemes. 
(fig.  41  B,  C,  n,  p)  may  project  from  the  walls  of  the  phallotreme. 
The  basal  part  of  the  dorsal  lobe  (B,  m)  usually  contains  a  sclerotiza- 
tion  in  its  lateral  walls,  from  which  a  pair  of  long  apodemal  arms 
{Apa),  the  "  endapophyses  "  of  Walker  (1922),  project  internally 
above  the  endophallus  (A).  The  endophallus  is  a  large  laterally 
compressed  sac,  with  a  narrowed  meatus  leading  inward  from  the 
