﻿EXTERNAL 
  CHARACTERS. 
  19 
  

  

  orbital 
  space 
  at 
  least 
  as 
  broad 
  as 
  the 
  upper 
  

   eyelid 
  9. 
  Bufo 
  vulgaris. 
  

  

  Toes 
  at 
  least 
  nearly 
  balf 
  webbed, 
  with 
  single 
  

   subarticular 
  tubercles 
  ; 
  a 
  tarsal 
  fold 
  ; 
  fingers 
  

   very 
  obtuse 
  ; 
  interorbital 
  space 
  narrower 
  than 
  

   the 
  upper 
  eyelid 
  . 
  10. 
  Bufo 
  viridis. 
  

  

  Toes 
  webbed 
  at 
  the 
  base, 
  with 
  paired 
  subarticular 
  

   tubercles 
  ; 
  a 
  tarsal 
  fold 
  usually 
  present 
  ; 
  inter- 
  

   orbital 
  space 
  narrower 
  than 
  the 
  upper 
  eyelid 
  ; 
  

   hind 
  limb 
  not, 
  or 
  but 
  slightly, 
  longer 
  than 
  head 
  

   and 
  body 
  . 
  . 
  . 
  .11. 
  Bufo 
  calamita. 
  

  

  IV. 
  Tongue 
  cordiforra, 
  free 
  behind; 
  fingers 
  and 
  toes 
  

   dilated 
  at 
  the 
  end 
  into 
  distinct 
  disks 
  ; 
  fingers 
  

   webbed 
  at 
  the 
  base 
  ; 
  vomerine 
  teeth 
  between 
  

   the 
  choanaB 
  ; 
  pupil 
  horizontal 
  (HYLiDiE). 
  

  

  12. 
  Hyla 
  arbor 
  ea, 
  

  

  V. 
  Tongue 
  forked 
  and 
  free 
  behind 
  ; 
  pupil 
  horizontal 
  

   (Ranid^). 
  

  

  A. 
  Vomerine 
  teeth 
  between 
  or 
  extending 
  slightly 
  

  

  behind 
  the 
  level 
  of 
  the 
  choanse 
  ; 
  interorbital 
  

   space 
  not 
  more 
  than 
  half 
  as 
  broad 
  as 
  the 
  

   upper 
  eyelid 
  . 
  .13. 
  Bana 
  esmlenta. 
  

  

  B. 
  Vomerine 
  teeth 
  extending 
  behind 
  the 
  level 
  of 
  

  

  the 
  choanae 
  ; 
  interorbital 
  space 
  at 
  least 
  one- 
  

   . 
  half 
  the 
  width 
  of 
  the 
  upper 
  eyelid. 
  

   1. 
  Tibio-tarsal 
  articulation 
  rarely 
  reaching 
  the 
  

   tip 
  of 
  the 
  snout, 
  and 
  never 
  beyond; 
  

   distance 
  between 
  the 
  dorso-lateral 
  folds 
  

   five 
  to 
  seven 
  times 
  in 
  the 
  length 
  from 
  

   snout 
  to 
  vent. 
  

   Inner 
  metatarsal 
  tubercle 
  large, 
  hard, 
  compressed, 
  

   measuring 
  one-half 
  to 
  two-thirds 
  its 
  distance 
  

   from 
  the 
  tip 
  of 
  the 
  inner 
  toe 
  ; 
  first 
  finger 
  

   extending 
  beyond 
  second; 
  tibia 
  shorter 
  than 
  

   the 
  fore 
  limb 
  . 
  . 
  . 
  14, 
  Rana 
  arvalis. 
  

   Inner 
  metatarsal 
  tubercle 
  small, 
  soft, 
  oval; 
  first 
  

   and 
  second 
  fingers 
  equal, 
  or 
  first 
  extending 
  

  

  