﻿PLATE 
  III. 
  

  

  [TLo 
  Bpecimens 
  rcpresente;! 
  ia 
  this 
  plAte 
  were 
  removed 
  from 
  tbc 
  ova, 
  and 
  

   were 
  about 
  two-sixteenths 
  of 
  an 
  inch 
  in 
  length.] 
  

  

  Fig. 
  1 
  — 
  Embryo 
  before 
  hatching 
  ; 
  .sho\Ying 
  both 
  ends 
  of 
  in- 
  

   testine, 
  (page 
  68); 
  the 
  anal 
  vacuole, 
  (ibid); 
  the 
  

   ear 
  with 
  its 
  otoliths 
  ; 
  the 
  heart 
  and 
  the 
  branchial 
  

   vesicles, 
  (page 
  69.) 
  Tlie 
  nasal 
  pouch 
  should 
  be 
  

   represented 
  in 
  this 
  Fig. 
  as 
  a 
  disk-like 
  marking, 
  

   just 
  anterior 
  to 
  tlie 
  eye, 
  much 
  as 
  shown 
  in 
  Fig. 
  

   2. 
  

  

  Fig. 
  2— 
  Earlier 
  stage 
  than 
  Fig. 
  1. 
  Tiie 
  intestine 
  is 
  repre- 
  

   sented 
  by 
  a 
  posterior 
  cixjcum, 
  (page 
  67); 
  and 
  the 
  

   heart 
  by 
  a 
  small 
  pulsatile, 
  pear-shaped 
  organ, 
  

   (page 
  67.) 
  

  

  Fig. 
  3— 
  Enlarged 
  view 
  of 
  tlie 
  anal 
  portion 
  of 
  Fig. 
  1, 
  

   (page 
  70.) 
  a— 
  Indications 
  of 
  blood-vessel 
  tracts, 
  

   b 
  — 
  Anal 
  vacuole. 
  

  

  Fig. 
  4 
  —Profile 
  of 
  portion 
  of 
  embryo, 
  showing 
  tubular 
  con- 
  

   dition 
  of 
  the 
  heart, 
  (page 
  68.) 
  

  

  Fig. 
  6 
  — 
  In 
  this 
  Fig. 
  the 
  heart 
  is 
  represented 
  as 
  beginning 
  

   to 
  form 
  two 
  portions, 
  (page 
  69); 
  and 
  the 
  bran- 
  

   chial 
  vesicles 
  arc 
  all 
  visible, 
  (page 
  69.) 
  

  

  