﻿288 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  the 
  scutum 
  is, 
  so 
  to 
  speak, 
  cleft 
  in 
  two 
  by 
  the 
  meeting 
  of 
  the 
  prsescutum 
  

   and 
  scutellum 
  in 
  the 
  median 
  line. 
  The 
  flanks 
  of 
  the 
  thorax, 
  or 
  pleurites, 
  

   are 
  often 
  very 
  large, 
  and 
  the 
  episternum 
  and 
  epimerum 
  are 
  broad, 
  oblong, 
  

   or 
  squarish, 
  and 
  these 
  sclerites 
  are 
  sometimes 
  subdivided 
  into 
  an 
  upper 
  

   and 
  lower 
  division 
  (supra- 
  aud 
  infra- 
  epimerum 
  or 
  episternum). 
  The 
  

   sternum 
  is 
  often 
  large, 
  flat, 
  and 
  broad 
  5 
  it 
  is 
  sometimes 
  divided 
  into 
  a 
  

   sternum 
  and 
  praesternum. 
  

  

  The 
  wings 
  are 
  usually 
  net- 
  veined, 
  often 
  with 
  numerous 
  longitudinal 
  

   veins, 
  the 
  branches 
  of 
  the 
  subcostal, 
  median, 
  and 
  submedian 
  veins 
  being 
  

   either 
  very 
  long 
  and 
  parallel 
  with 
  the 
  longitudinal 
  axis 
  of 
  the 
  wing, 
  or 
  

   numerous 
  and 
  small 
  (especially 
  in 
  the 
  hind 
  wings 
  of 
  Orthoptera). 
  

  

  The 
  hind 
  wings 
  are 
  often 
  (Orthoptera 
  and 
  Ov 
  oiiata) 
  broader 
  and 
  

   larger 
  than 
  the 
  anterior 
  pair, 
  the 
  metathorax 
  in 
  such 
  casesbeing 
  a 
  little 
  

   larger 
  than 
  the 
  mesothorax. 
  

  

  The 
  abdomen 
  has 
  in 
  this 
  group, 
  including 
  representatives 
  of 
  the 
  

   Keuroptera, 
  Orthoptera, 
  Dermatoptera 
  and 
  Pseudoneuroptera, 
  besides 
  

   a 
  tenth, 
  nearly 
  complete 
  segment, 
  the 
  rudiments 
  of 
  an 
  eleventh 
  uro- 
  

   mere,^^^ 
  represented 
  by 
  a 
  tergite 
  forming 
  the 
  supra-anal 
  triangular 
  plate. 
  

   Well 
  developed 
  jointed 
  cercopoda 
  occur 
  in 
  the 
  Orthoptera 
  and 
  Pseudo- 
  

   neuroptera, 
  while 
  the 
  forceps 
  of 
  Forficul^) 
  (Dermatoptera) 
  are 
  un- 
  

   doubtedly 
  modified 
  cercopoda. 
  An 
  ovipositor 
  occurs 
  in 
  the 
  l!^europtera 
  

   (Panorpidse) 
  and 
  Orthoptera. 
  

  

  The 
  metamorphosis 
  is 
  incomplete 
  in 
  all 
  the 
  orders 
  of 
  Fhyloptera 
  ex- 
  

   cept 
  the 
  more 
  recent 
  and 
  higher 
  order, 
  i. 
  e., 
  the 
  Keuroptera 
  (in 
  Erichson's 
  

   sense), 
  in 
  which 
  the 
  transformations 
  are 
  complete, 
  the 
  pupa 
  being 
  qui- 
  

   escent 
  and 
  wholly 
  unlike 
  the 
  larva. 
  

  

  The 
  relative 
  standing 
  of 
  the 
  four 
  orders 
  of 
  Fhyloptera 
  is 
  shown 
  in 
  

   the 
  table 
  or 
  genealogical 
  tree 
  of 
  the 
  winged 
  insects 
  on 
  page 
  295. 
  

  

  The 
  sequence 
  of 
  the 
  orders, 
  such 
  as 
  we 
  are 
  compelled 
  to 
  adopt 
  in 
  

   writing 
  or 
  speaking 
  of 
  them, 
  is 
  difficult 
  to 
  decide 
  upon. 
  Beginning 
  with 
  

   what 
  on 
  the 
  whole 
  may 
  be 
  regarded 
  as 
  the 
  lowest 
  order, 
  we 
  might 
  first 
  

   take 
  up 
  the 
  Dermatoptera, 
  which 
  are 
  in 
  most 
  respects 
  the 
  most 
  general- 
  

   ized 
  forms, 
  and 
  stand 
  nearest 
  to 
  the 
  Thysanura 
  (Japyx). 
  

  

  issifoMENCLATUKE 
  OF 
  EXTEKNAL 
  PARTS 
  OF 
  Arthkopoda.— 
  The 
  following 
  terms 
  have 
  been 
  devised 
  

   for 
  convenience 
  in 
  anatomical 
  and 
  systematic 
  work 
  on 
  the 
  Aithropoda, 
  and 
  are 
  submitted 
  for 
  the 
  judg- 
  

   ment 
  of 
  naturalists. 
  We 
  have 
  adopted 
  most 
  of 
  them 
  in 
  a 
  monograph 
  of 
  N. 
  A. 
  Phyllopoda, 
  published 
  

   in 
  Hayden's 
  Twelfth 
  Annual 
  Report 
  U. 
  S. 
  Geol. 
  Surv. 
  Terr., 
  1883. 
  

  

  The 
  term 
  arthromere, 
  originally 
  employed 
  in 
  the 
  author's 
  "Guide 
  to 
  the 
  Study 
  of 
  Insects," 
  in 
  18G9, 
  

   is 
  now 
  restricted 
  to 
  the 
  body-segments 
  of 
  Arthropods, 
  the 
  term 
  zonite 
  or 
  somite 
  being 
  used 
  for 
  the 
  

   body-segments 
  of 
  worms, 
  etc., 
  as 
  well 
  as 
  Arthropods. 
  The 
  "head," 
  "thorax" 
  and 
  "abdomen" 
  may 
  be 
  

   termed 
  respectively 
  cephalosome, 
  hcenosome 
  (Gr. 
  baino, 
  to 
  walk, 
  locomotion), 
  and 
  urosome. 
  The 
  head- 
  

   segments 
  are 
  termed 
  cephalomeres, 
  the 
  thoracic 
  segments 
  hcmiomeres, 
  and 
  the 
  abdominal 
  uromeres, 
  

   Por 
  the 
  antennae 
  the 
  term 
  cesthopoda, 
  and 
  for 
  the 
  mandibles 
  and 
  maxillae 
  the 
  previously 
  used 
  term 
  

   gnathopoda 
  is 
  adopted. 
  

  

  The 
  thoracic 
  legs 
  are 
  termed 
  bcenopoda, 
  and 
  Westwood's 
  term 
  uropoda, 
  applied 
  by 
  him 
  to 
  the 
  terminal 
  

   pairs 
  of 
  feet 
  of 
  the 
  Tetradecapoda, 
  is 
  extended 
  to 
  all 
  the 
  abdominal 
  feet 
  of 
  Arthropods. 
  The 
  basal 
  

   abdominal 
  feet 
  of 
  male 
  Decapoda, 
  modified 
  as 
  accessory 
  reproductive 
  organs, 
  are 
  termed, 
  for 
  conveni- 
  

   ence 
  in 
  descriptive 
  carcinology, 
  gonopoda, 
  and 
  the 
  jointed 
  anal 
  cerci 
  of 
  certain 
  insects 
  and 
  of 
  Apus 
  

   are 
  termed 
  cercopoda 
  (/ce'p<cos, 
  tail; 
  jrov?, 
  :ro56s, 
  foot). 
  The 
  elemen-ts 
  of 
  the 
  ovipositor 
  or 
  sting 
  are 
  three 
  

   pairs 
  of 
  blade-like 
  appendages 
  which 
  are 
  homologues 
  of 
  the 
  legs 
  ; 
  they 
  may 
  therefore 
  be 
  designated 
  aa 
  

   oopoda, 
  as 
  they 
  are 
  chiefly 
  concerned 
  in 
  egg-laying. 
  

  

  