﻿202 
  

  

  PELOBATID^. 
  

  

  are 
  small, 
  2 
  to 
  2i 
  mm. 
  in 
  diameter, 
  grey 
  or 
  brown 
  

   with 
  white 
  lower 
  pole, 
  and 
  develop 
  rapidlv 
  ; 
  the 
  em- 
  

   bryo, 
  gill-less 
  and 
  tailless, 
  breaks 
  through 
  about 
  the 
  

   fifth 
  or 
  sixth 
  day, 
  and 
  attaches 
  itself, 
  through 
  its 
  

   adhesive 
  subcephalic 
  apparatus, 
  to 
  the 
  outer 
  surface 
  

   of 
  the 
  mucilage. 
  

  

  Fig. 
  76. 
  

  

  Tadpole 
  (PI. 
  II, 
  fig. 
  1). 
  — 
  Length 
  of 
  body 
  once 
  and 
  

   a 
  half 
  to 
  twice 
  its 
  width, 
  one-half 
  to 
  two-thirds 
  the 
  

   length 
  of 
  the 
  tail. 
  Nostrils 
  a 
  little 
  nearer 
  the 
  eyes 
  

   than 
  the 
  end 
  of 
  the 
  snout. 
  Eyes 
  on 
  the 
  upper 
  sur- 
  

   face, 
  equidistant 
  from 
  the 
  end 
  of 
  the 
  snout 
  and 
  the 
  

   spiraculum, 
  the 
  distance 
  between 
  them 
  at 
  least 
  twice, 
  

   sometimes 
  nearly 
  three 
  times 
  as 
  great 
  as 
  that 
  between 
  

   the 
  nostrils, 
  and 
  greater 
  than 
  the 
  width 
  of 
  the 
  mouth. 
  

   Spiracnlum 
  on 
  the 
  left 
  side, 
  directed 
  upwards 
  and 
  

   backwards, 
  equidistant 
  from 
  either 
  extremity 
  of 
  the 
  

   body 
  or 
  a 
  little 
  nearer 
  the 
  anterior 
  extremity, 
  visible 
  

   from 
  above 
  and 
  from 
  below. 
  Anal 
  opening 
  median, 
  

   a 
  little 
  larger 
  than 
  the 
  spiraculum, 
  and 
  close 
  to 
  the 
  

   body. 
  Tail 
  twice 
  and 
  a 
  half 
  to 
  thrice 
  and 
  one-fifth 
  as 
  

   long 
  as 
  deep, 
  acutely 
  pointed 
  ; 
  npjDer 
  crest 
  convex, 
  

   slightly 
  deeper 
  than 
  the 
  lower, 
  not 
  extending 
  far 
  

   upon 
  the 
  back 
  ; 
  the 
  depth 
  of 
  the 
  muscular 
  portion 
  

   at 
  its 
  base 
  about 
  half 
  the 
  greatest 
  total 
  depth. 
  

  

  Beak 
  black. 
  Lip 
  bordered 
  with 
  papillae, 
  which 
  form 
  

   two 
  or 
  more 
  rows 
  on 
  the 
  sides 
  ; 
  the 
  papillose 
  border 
  

   interrupted 
  mesially 
  by 
  a 
  narrow 
  toothed 
  descending 
  

   lobe, 
  which 
  appears 
  at 
  first 
  sight 
  as 
  continuous 
  with 
  

   the 
  second 
  upper 
  series 
  of 
  teeth. 
  This 
  anterior 
  series 
  

   is 
  followed 
  by 
  three 
  or 
  four 
  other 
  series 
  of 
  teeth, 
  

   which 
  are 
  all 
  widely 
  interrupted 
  in 
  the 
  middle 
  and 
  

  

  