﻿212 
  KEPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  sections, 
  though 
  in 
  surface 
  views 
  they 
  appear 
  very 
  plainly; 
  inside 
  the 
  

   coat 
  of 
  circular 
  muscles 
  all 
  the 
  fibres 
  are 
  transversely 
  striated. 
  The 
  

   teeth 
  form 
  six 
  distinct 
  arches, 
  and 
  are 
  united 
  with 
  the 
  muscular 
  coat 
  

   only 
  at 
  their 
  sides. 
  The 
  attachments 
  of 
  the 
  adjacent 
  teeth 
  to 
  the 
  mus- 
  

   cularis 
  are 
  separated 
  by 
  a 
  longitudinal 
  ridge, 
  a, 
  which 
  runs 
  unbroken 
  

   through 
  the 
  length 
  of 
  the 
  crop, 
  separating 
  the 
  neighboring 
  rows 
  of 
  teeth 
  

   (compare 
  a 
  surface 
  view 
  Fig. 
  54 
  a). 
  Each 
  tooth 
  is 
  tripartite, 
  having 
  a 
  

   central 
  pointed 
  division, 
  d', 
  and 
  two 
  lateral 
  protuberances, 
  d", 
  which 
  

   Wilde 
  terms 
  "molar" 
  (mahlzalmartig). 
  The 
  shape 
  of 
  these 
  is 
  best 
  ex- 
  

   plained 
  by 
  the 
  figure. 
  The 
  whole 
  proventriculus 
  is 
  lined 
  by 
  a 
  contin- 
  

   uous 
  resistent 
  cuticula, 
  which 
  rests 
  upon 
  a 
  cylinder-epithelium, 
  that 
  

   varies 
  greatly 
  in 
  height 
  in 
  different 
  regions 
  of 
  the 
  teeth, 
  as 
  is 
  plainly 
  

   shown 
  in 
  Fig. 
  58, 
  ep. 
  The 
  epithelium 
  rests 
  on 
  a 
  layer 
  of 
  connective 
  tissue 
  

   conn., 
  beneath 
  which 
  is 
  the 
  space 
  left 
  by 
  the 
  dental 
  arch; 
  this 
  space, 
  (7, 
  

   corresponds 
  to 
  a 
  large 
  canal 
  which 
  runs 
  under 
  each 
  row 
  of 
  teeth. 
  Ex- 
  

   amined 
  from 
  the 
  surface, 
  Fig. 
  54, 
  the 
  same 
  disposition 
  of 
  the 
  parts 
  can 
  

   be 
  seen, 
  though 
  less 
  plainly. 
  The 
  central 
  process 
  of 
  each 
  tooth 
  is 
  pointed 
  

   and 
  inclined 
  backwards, 
  so 
  as 
  to 
  slightly 
  overlap 
  the 
  next 
  following 
  

   tooth. 
  Certain 
  of 
  the 
  anterior 
  " 
  molar" 
  protuberances 
  are 
  distinguished 
  

   from 
  the 
  posterior, 
  by 
  having 
  three 
  dark 
  colored 
  projections 
  of 
  their 
  cu- 
  

   ticula. 
  The 
  cuticula 
  is 
  armed 
  with 
  spines 
  upon 
  the 
  central 
  dental 
  divis- 
  

   ion, 
  and 
  with 
  numerous 
  bristles 
  upon 
  the 
  "molar" 
  protuberances 
  and 
  

   interdental 
  ridge. 
  A 
  side 
  view, 
  Fig. 
  55, 
  is 
  also 
  given 
  in 
  order 
  to 
  make 
  

   the 
  relation 
  of 
  the 
  teeth 
  to 
  one 
  another 
  as 
  plain 
  as 
  possible. 
  

  

  In 
  the 
  anterior 
  part 
  of 
  the 
  proventriculus 
  the 
  teeth 
  are 
  simpler 
  in 
  

   form, 
  and 
  the 
  longitudinal 
  ridge 
  and 
  " 
  molar" 
  protuberances 
  are 
  want- 
  

   ing. 
  The 
  cuticula 
  gives 
  off 
  a 
  dense 
  coat 
  of 
  long 
  hairs. 
  The 
  edge 
  of 
  

   each 
  tooth 
  is 
  deeply 
  serrated 
  on 
  both 
  sides 
  of 
  its 
  point, 
  instead 
  of 
  being 
  

   merely 
  somewhat 
  roughened 
  as 
  in 
  the 
  posterior 
  part. 
  Finally 
  these 
  an- 
  

   terior 
  teeth 
  are 
  convex 
  on 
  their 
  front, 
  concave 
  on 
  their 
  hinder 
  sides. 
  

   They 
  become 
  smaller 
  as 
  we 
  go 
  forward, 
  the 
  rows 
  spreading 
  apart 
  as 
  they 
  

   widen 
  out 
  to 
  form 
  the 
  crop. 
  

  

  Posteriorly 
  the 
  rows 
  of 
  teeth 
  stop 
  quite 
  suddenly. 
  The 
  interdental 
  

   ridge 
  runs 
  somewhat 
  further 
  on, 
  and 
  is 
  rounded 
  off 
  at 
  its 
  termination. 
  

   On 
  the 
  last 
  five 
  or 
  six 
  teeth 
  the 
  middle 
  process 
  gradually 
  loses 
  its 
  prom- 
  

   inence, 
  and 
  on 
  the 
  last 
  two 
  the 
  " 
  molar 
  " 
  processes 
  are 
  also 
  very 
  much 
  re- 
  

   duced. 
  

  

  The 
  total 
  number 
  of 
  teeth 
  in 
  each 
  row 
  is 
  twenty 
  three 
  or 
  four, 
  of 
  which 
  

   eight 
  or 
  nine 
  belong 
  to 
  the 
  anterior 
  and 
  fifteen 
  to 
  the 
  posterior 
  division. 
  

   In 
  Gryllus 
  campestris 
  and 
  domcsticus 
  the 
  crop, 
  likewise, 
  forms 
  two 
  divis- 
  

   ions, 
  in 
  the 
  posterior 
  of 
  which 
  there 
  are 
  fifteen 
  teeth 
  in 
  each 
  row. 
  It 
  is 
  

   to 
  the 
  posterior 
  division 
  alone 
  that 
  Wilde 
  (1. 
  c.) 
  restricts 
  the 
  name 
  pro- 
  

   ventriculus, 
  but 
  I 
  cannot 
  see 
  what 
  grounds 
  he 
  has 
  for 
  so 
  doing, 
  for 
  the 
  

   two 
  parts 
  have 
  essentially 
  the 
  same 
  characteristics. 
  

  

  Stomach. 
  — 
  This 
  name 
  I 
  apply 
  to 
  the 
  ventriculus 
  of 
  authors, 
  the 
  Chy-. 
  

   lusmagen 
  of 
  the 
  Germans, 
  Fig. 
  45, 
  vcn. 
  Of 
  no 
  part 
  of 
  the 
  digestive 
  

  

  