NO.    5      MALE  GENITALIA  OF  ORTHOPTEROID  INSECTS — SNODGRASS        I9 
clypeus  (Clp)  and  a  fairly  large  labrum  {Lin).  The  labral  muscles 
arise  on  the  cranial  area  between  the  bases  of  the  antennae,  demon- 
strating that  this  area  is  the  frons  (Pr).  In  the  Psocidae  the  enlarged 
postclypeus  intervenes  between  a  small  anteclypeus  and  the  reduced 
frontal  region,  and  the  labral  muscles,  as  shown  by  Badonnel  (1934), 
traverse  the  postclypeus  from  their  dorsal  origins  on  the  frons. 
The  internal  reproductive  organs  of  Zorotypus  are  difficult  to  study, 
and  the  writer  has  not  been  able  to  make  a  satisfactory  dissection  of 
them.  In  mature  males,  however,  there  are  always  to  be  found  three 
very  delicate  membranous  sacs  containing  coiled  bundles  of  enormous 
spermatozoa.  The  spermatozoa  were  observed  by  Silvestri  (1913), 
and  also  by  Crampton  (1920a),  who  refers  to  them  as  "wavy"  or 
"  crinkly  "  fibers.  The  bundles  of  spermatozoa  are  very  similar  to 
those  of  the  mantid  Tcnodcra,  and  when  a  single  sperm  thread 
is  straightened  out  it  is  actually  as  long  as  or  longer  than  the  entire 
insect.  In  the  psocid  Stcnopsocus,  according  to  Badonnel  (1934), 
there  is  a  pair  of  huge  sperm  vesicles,  each  vesicle  subdivided  into 
two  chambers  with  thick  glandular  walls.  The  testes  of  Zorotypus, 
Silvestri  says,  are  situated  dorsally  in  the  third  and  fourth  abdominal 
segments,  and  the  vasa  deferentia  unite  to  form  a  long,  variously 
folded  ejaculatory  duct. 
The  abdomen  of  the  male  of  Zorotypus  hubhardi  has  eight  well- 
defined  segments  (fig.  5  C).  The  tergum  of  the  ninth  segment,  how- 
ever, is  reduced  to  a  narrow  sclerite  {I XT)  with  a  small  median 
tooth,  and  the  venter  of  this  segment  is  unsclerotized,  though  it  forms 
a  large  subgenital  lobe  {IX. V).  Dorsally  the  abdomen  terminates 
with  a  small  anal  tube  {ant),  from  beneath  which  projects  a  pair 
of  genital  lobes.  The  genitalia  of  Zorotypus  hubbardi  have  been  de- 
scribed by  Crampton  (1920  a)  and  by  Walker -(1922).  The  genital 
lobes  (phallomeres)  lie  side  by  side,  one  right,  the  other  left,  but  the 
position  of  the  gonopore  has  not  been  determined.  The  left  genital 
lobe  (D,  IPhm)  tapers  distally  to  a  point;  the  right  one  {rPhui) 
is  flattened,  bears  distally  a  small  papilla,  and  proximally  a  slender 
process  directed  posteriorly. 
V.    GRYLLOBLATTOIDEA 
The  relationships  of  the  grylloblattids  has  been  a  subject  of  dis- 
cussion and  difference  of  opinion  ever  since  the  insects  have  been 
known,  and  the  very  name  of  the  first  described  genus  and  species, 
Grylloblatta  campodcifonnis  Walker  (1914),  seems  to  provide  for 
most  any  taxonomic  eventuality.  There  is  no  question  that  the  gryl- 
loblattids are  orthopteroid  insects ;  it  is  their  position   within   this 
