﻿EANA. 
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  region. 
  Eight 
  species 
  are 
  known 
  to 
  occur 
  in 
  Europe; 
  

   they 
  may 
  be 
  distinguished 
  by 
  means 
  of 
  the 
  following 
  

   synopsis 
  : 
  

  

  I. 
  Vomerine 
  teeth 
  between 
  the 
  choanoe 
  or 
  extending 
  

   slightly 
  beyond 
  their 
  posterior 
  borders 
  ; 
  inter- 
  

   orbital 
  space 
  very 
  narrow, 
  measuring 
  one-third 
  

   to 
  one-half 
  the 
  width 
  of 
  the 
  upper 
  eyelid 
  ; 
  male 
  

   with 
  external 
  vocal 
  sacs 
  ; 
  colour 
  often 
  green. 
  

  

  B. 
  esculenta. 
  

   II. 
  Vomerine 
  teeth 
  behind 
  the 
  level 
  of 
  the 
  choanae 
  ; 
  

   vocal 
  sacs 
  internal 
  or 
  absent; 
  colour 
  never 
  

   green. 
  

  

  a. 
  Tibio-tarsal 
  articulation 
  rarely 
  reaching 
  the 
  

  

  tip 
  of 
  the 
  snout 
  and 
  never 
  beyond 
  ; 
  distance 
  

   between 
  the 
  dorso-lateral 
  glandular 
  folds 
  

   contained 
  five 
  to 
  seven 
  times 
  in 
  the 
  length 
  

   from 
  snout 
  to 
  vent 
  ; 
  male 
  with 
  internal 
  

   vocal 
  sacs. 
  

  

  Inner 
  metatarsal 
  tubercle 
  large, 
  hard, 
  com- 
  

   pressed, 
  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. 
  B. 
  arvalis. 
  

  

  Inner 
  metatarsal 
  tubercle 
  small, 
  soft, 
  oval 
  ; 
  

   first 
  and 
  second 
  fingers 
  equal, 
  or 
  first 
  

   extending 
  slightly 
  beyond 
  second 
  ; 
  tibia 
  as 
  

   long 
  as 
  or 
  slightly 
  shorter 
  than 
  the 
  fore 
  

   limb 
  B. 
  camerani. 
  

  

  Inner 
  metatarsal 
  tubercle 
  small, 
  soft, 
  oval; 
  

   first 
  finger 
  extending 
  beyond 
  second 
  ; 
  tibia 
  

   considerably 
  shorter 
  than 
  the 
  fore 
  limb. 
  

  

  B. 
  temporaria. 
  

  

  b. 
  Tibio-tarsal 
  articulation 
  reaching 
  the 
  tip 
  of 
  

  

  the 
  snout 
  or 
  beyond; 
  tibia 
  as 
  long 
  as 
  or 
  a 
  little 
  

   shorter 
  than 
  the 
  fore 
  limb 
  ; 
  distance 
  between 
  

   the 
  dorso-lateral 
  glandular 
  folds 
  contained 
  

  

  four 
  to 
  five 
  and 
  a 
  half 
  times 
  in 
  the 
  length 
  

   from 
  snout 
  to 
  vent; 
  male 
  without 
  vocal 
  sacs. 
  

  

  