﻿604 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  [116] 
  

  

  EXPLANATION 
  OF 
  PLATE 
  XXX. 
  

   Ictalurus 
  albidus. 
  (White 
  Cat-fish.) 
  

  

  Fig. 
  173. 
  Cartilaginous 
  crauium 
  of 
  young 
  fish, 
  ten 
  days 
  old, 
  constructed 
  from 
  a 
  series 
  

   of 
  longitudinal 
  vertical 
  sections, 
  x 
  35. 
  

   A 
  u, 
  auditory 
  vesicle 
  ; 
  CEy, 
  ceratohyal 
  ; 
  Cor, 
  coracoid 
  ; 
  EE, 
  ectethmoid 
  ridge 
  : 
  Eb, 
  car- 
  

   tilage 
  of 
  external 
  chin 
  barbel 
  ; 
  Fo, 
  fontanelle 
  ; 
  GHy, 
  urobyal 
  ; 
  lb, 
  cartilage 
  of 
  

   internal 
  chin 
  barbel 
  ; 
  IEy, 
  interhyal 
  ; 
  Em, 
  hyomaudibular 
  ; 
  EEy, 
  hypohyal; 
  Mk, 
  

   Meckel's 
  cartilage; 
  Mxb, 
  cartilage 
  of 
  maxillary 
  barbel; 
  0, 
  orbit; 
  01, 
  olfactory 
  

   fossa; 
  PaC, 
  parachordal 
  region; 
  Phb, 
  pharyngobranchials; 
  Ps, 
  presphenoid 
  la- 
  

   mina; 
  PIPt, 
  palatopterygoid 
  elements; 
  B, 
  rostrum; 
  Sc, 
  scapular 
  portion 
  of 
  

   shoulder-girdle; 
  so, 
  supraoccipital 
  ; 
  TCr, 
  tegmen 
  cranii; 
  Tr, 
  trabecula; 
  II, 
  V, 
  

   VII, 
  IX, 
  X, 
  foramina 
  for 
  cranial 
  nerves. 
  

  

  Fig. 
  174. 
  Median 
  longitudinal 
  vertical 
  section 
  of 
  the 
  bead 
  of 
  a 
  young 
  fish, 
  ten 
  days 
  old. 
  

   x35. 
  

   Ab, 
  air-bladder 
  ; 
  BB, 
  basibranchials 
  ; 
  Ba, 
  bulbus 
  aortse 
  ; 
  Cb, 
  cerebellum 
  ; 
  Cer, 
  cere- 
  

   brum 
  ; 
  Ch, 
  chorda 
  ; 
  ES, 
  erector 
  spinse 
  ; 
  Ey, 
  bypophysis 
  ; 
  I, 
  intestine 
  ; 
  Inf, 
  infun- 
  

   dibulum 
  ; 
  L, 
  liver 
  ; 
  M, 
  pharyngeal 
  and 
  oesophageal 
  muscles 
  ; 
  mb, 
  mid-brain 
  ; 
  ME, 
  

   Meckel's 
  cartilage 
  ; 
  mo, 
  medulla 
  oblongata 
  ; 
  Oe, 
  oesophagus 
  ; 
  Ot, 
  optic 
  tract 
  ; 
  P, 
  

   periblast 
  ; 
  Pc, 
  pericardiac 
  cavity 
  ; 
  Pn, 
  pineal 
  body 
  ; 
  B, 
  rostrum 
  ; 
  S, 
  sacculns 
  

   vasculosus; 
  SV, 
  sinus 
  venosus; 
  Tr, 
  trabecula; 
  Ve, 
  ventricle; 
  x 
  x 
  x, 
  rudiments 
  

   of 
  anterior 
  co-ossified 
  vertebrae 
  ; 
  Y, 
  yelk. 
  

  

  