﻿590 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  [102] 
  

  

  EXPLANATION 
  OF 
  PLATE 
  XXIII. 
  

  

  Ictalurus 
  albidus. 
  (White 
  Cat-fish.) 
  

  

  Fig. 
  154. 
  Embryo 
  of 
  the 
  second 
  day 
  removed 
  from 
  its 
  envelope; 
  b 
  rudimentary 
  branch- 
  

   ial 
  arches 
  and 
  clefts, 
  e 
  eye, 
  m 
  m 
  myotomes, 
  p 
  pectoral 
  plate 
  or 
  thickening. 
  Drawn 
  

   from 
  a 
  hardened 
  specimen, 
  x 
  24. 
  

  

  Fig. 
  155. 
  Living 
  embryo 
  of 
  the 
  second 
  day 
  freed 
  from 
  its 
  envelope, 
  and 
  viewed 
  as 
  a 
  

   transparent 
  object, 
  x 
  16. 
  

  

  Fig. 
  156. 
  Head 
  of 
  embryo 
  on 
  the 
  third 
  day, 
  viewed 
  from 
  in 
  front 
  and 
  somewhat 
  

   obliquely 
  ; 
  h 
  heart, 
  bl 
  maxillary 
  barbel, 
  x 
  16. 
  

  

  Fig. 
  157. 
  Head 
  of 
  embryo 
  on 
  the 
  third, 
  from 
  in 
  front, 
  viewed 
  as 
  an 
  opaque 
  object 
  ; 
  bl 
  

   maxillary 
  barbels, 
  h 
  heart, 
  n 
  nasal 
  grooves, 
  x 
  24. 
  

  

  Fig. 
  158. 
  Head 
  of 
  embryo 
  on 
  the 
  third 
  day, 
  from 
  the 
  side, 
  viewed 
  as 
  an 
  opaque 
  object 
  ; 
  

   b 
  branchiae, 
  bl 
  barbels, 
  m 
  myotomes, 
  p 
  pectoral, 
  x 
  24. 
  

  

  FlG. 
  159. 
  Embryo 
  of 
  third 
  day 
  freed 
  from 
  its 
  envelope, 
  and 
  viewed 
  from 
  above, 
  as 
  an 
  

   opaque 
  object 
  ; 
  op 
  opercular 
  fold, 
  p 
  pectoral, 
  mm 
  myotomes, 
  x 
  24. 
  

  

  