﻿CUONDEOSTEID^. 
  

  

  31 
  

  

  P. 
  616. 
  Type 
  specimen 
  of 
  CJiondrosteus 
  crassior, 
  Egerton, 
  figured 
  

   loc. 
  cit. 
  pi. 
  lxviii., 
  displaying 
  vertically 
  crushed 
  remains 
  of 
  

   the 
  head, 
  pectoral 
  arch, 
  and 
  pectoral 
  fins. 
  The 
  cranial 
  

   roof-bones 
  and 
  the 
  outer 
  face 
  of 
  the 
  clavicle 
  ("scapulo- 
  

   coracoid") 
  exhibit 
  few 
  coarse 
  tuberculations, 
  apparently 
  

   not 
  coated 
  with 
  ganoine 
  ; 
  the 
  pectoral 
  fin-rays 
  show 
  few 
  

   traces 
  of 
  nodose 
  granulations. 
  The 
  clavicle 
  has 
  a 
  distinct 
  

   inferior 
  limb, 
  and, 
  so 
  far 
  as 
  preserved, 
  resembles 
  in 
  shape 
  

   that 
  of 
  Acipenser. 
  Egerton 
  Coll. 
  

  

  P. 
  2048. 
  Head 
  and 
  pectoral 
  arch, 
  with 
  fins, 
  inferior 
  aspect, 
  de- 
  

   scribed 
  and 
  figured 
  by 
  E. 
  H. 
  Traquair, 
  loc. 
  cit. 
  p. 
  252, 
  fig. 
  3. 
  

   The 
  outline-illustration 
  is 
  copied, 
  of 
  one-half 
  the 
  natural 
  

   size, 
  in 
  the 
  accompanying 
  fig. 
  5, 
  and 
  an 
  actual 
  drawing 
  

   of 
  the 
  fossil 
  is 
  given 
  in 
  PI. 
  I. 
  fig. 
  2. 
  The 
  only 
  modification 
  

   in 
  Dr. 
  Traquair's 
  interpretation 
  occurs 
  in 
  the 
  pectoral 
  

   arch, 
  where 
  an 
  accidental 
  fracture 
  (V) 
  on 
  each 
  side 
  led 
  to 
  

   the 
  erroneous 
  determination 
  of 
  the 
  inferior 
  limb 
  of 
  the 
  

   clavicle 
  as 
  infraclavicle 
  in 
  the 
  original 
  description. 
  The 
  

   true 
  infraclavicle 
  (i.ch) 
  is 
  well 
  shown 
  in 
  the 
  lithographed, 
  

   figure. 
  Egerton 
  Coll. 
  

  

  P. 
  2049. 
  Head 
  with 
  opercular 
  apparatus, 
  pectoral 
  arch 
  and 
  portions 
  

   of 
  the 
  pectoral 
  fins, 
  lateral 
  and 
  partly 
  inferior 
  aspect, 
  

  

  Fig. 
  6. 
  

  

  Head 
  and 
  pectoral 
  arch 
  of 
  CJiondrosteus 
  acipenseroides, 
  lateral 
  and 
  

  

  partly 
  inferior 
  aspect 
  (after 
  Traquair). 
  [No. 
  P. 
  2049.] 
  

  

  For 
  explanation 
  of 
  lettering 
  see 
  opposite 
  page. 
  

  

  