﻿582 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  [94] 
  

  

  EXPLANATION 
  OF 
  PLATE 
  XIX. 
  

   Clupea 
  sapidissima. 
  (The 
  Common 
  Shad.) 
  

  

  Fig. 
  131. 
  Pneumatic 
  duct 
  pn, 
  rudimentary 
  stomach 
  st, 
  pylorus 
  py, 
  and 
  swollen 
  an- 
  

   terior 
  part 
  of 
  hind 
  gut 
  J, 
  and 
  back 
  part 
  of 
  oesophagus 
  oe, 
  of 
  a 
  young 
  shad 
  22 
  mm 
  

   long, 
  which 
  had 
  acquired 
  ventral 
  fins. 
  From 
  a 
  specimen 
  three 
  weeks 
  old 
  reared 
  

   in 
  confinement. 
  

  

  Fig. 
  132. 
  View 
  from 
  above 
  of 
  the 
  head 
  of 
  a 
  young 
  shad 
  fourteen 
  days 
  old, 
  showing 
  

   the 
  relations 
  of 
  the 
  auditory 
  capsules, 
  brain, 
  and 
  eyes. 
  

  

  Fig. 
  133. 
  Side 
  view 
  of 
  a 
  young 
  sbad 
  thirteen 
  days 
  old, 
  viewed 
  as 
  a 
  transparent 
  object. 
  

   db 
  rudimentary 
  air-bladder, 
  L 
  liver, 
  Gb 
  gall-bladder. 
  

  

  Figs. 
  134 
  and 
  135. 
  Two 
  views 
  of 
  the 
  heads 
  of 
  embryos 
  nearly 
  ready 
  to 
  hatch, 
  show- 
  

   ing 
  the 
  rudimentary 
  gill-arches 
  and 
  pectoral 
  fin, 
  nasal 
  pits, 
  wide 
  oral 
  fossa, 
  and 
  

   short 
  lower 
  jaw. 
  Drawn 
  from 
  opaque 
  specimens 
  bardened 
  in 
  chromic 
  acid. 
  

  

  Fig. 
  136. 
  An 
  embryo 
  in 
  its 
  envelope, 
  on 
  the 
  third 
  day 
  of 
  development, 
  nearly 
  ready 
  

   to 
  hatch. 
  

  

  Figs. 
  137, 
  138, 
  and 
  139. 
  A 
  lateral, 
  a 
  posterior, 
  and 
  a 
  view 
  from 
  above 
  of 
  the 
  blasto- 
  

   derm 
  of 
  the 
  shad, 
  just 
  at 
  the 
  time 
  the 
  cleavage 
  cavity, 
  sc, 
  is 
  beginning 
  to 
  be 
  evi- 
  

   dent, 
  the 
  tail 
  swelling, 
  s, 
  formed, 
  and 
  the 
  hypoblast 
  developed 
  by 
  inflection 
  of 
  

   the 
  edge 
  of 
  the 
  blastoderm. 
  

  

  Figs. 
  140 
  and 
  141. 
  Two 
  views 
  of 
  an 
  egg 
  after 
  the 
  blastoderm 
  has 
  spread 
  considerably 
  

   and 
  the 
  embryonic 
  area 
  e 
  is 
  well 
  defined. 
  From 
  photographs. 
  

  

  