﻿166 
  ACTINOPTERYGII. 
  

  

  peg-and-sockefc 
  articulation, 
  and 
  often 
  pectinated 
  at 
  the 
  hinder 
  

   border 
  ; 
  the 
  scales 
  of 
  the 
  middle 
  of 
  the 
  flank 
  scarcely 
  deeper 
  than 
  

   broad, 
  few 
  of 
  the 
  ventral 
  scales 
  much 
  broader 
  than 
  deep; 
  no 
  

   enlarged 
  ridge-scales. 
  

  

  This 
  is 
  the 
  least 
  specialised 
  genus 
  ascribed 
  to 
  the 
  Macrosemiidae, 
  

   and 
  may 
  be 
  regarded 
  as 
  a 
  link 
  between 
  this 
  family 
  and 
  that 
  of 
  the 
  

   Eugnathidse. 
  

  

  Ophiopsis 
  procera, 
  Agassiz. 
  

   1844. 
  Ophiopsis 
  procerus, 
  L. 
  Agassiz, 
  Poiss. 
  Foss. 
  vol. 
  ii. 
  pt. 
  i. 
  p. 
  289, 
  

  

  pi. 
  xlviii. 
  fig. 
  1. 
  

   1851. 
  Ophiopsis 
  procerus, 
  A. 
  Wagner, 
  Abh. 
  k. 
  bay. 
  Akad. 
  Wiss., 
  math.- 
  

  

  phys. 
  01. 
  vol. 
  vi. 
  p. 
  60. 
  

   1863. 
  Ophiopsis 
  procera, 
  A. 
  Wagner, 
  ibid. 
  vol. 
  ix. 
  p. 
  653. 
  

  

  Type. 
  Imperfectly 
  preserved 
  fish 
  ; 
  Palseontological 
  Museum, 
  

   Munich. 
  

  

  The 
  type 
  species, 
  attaining 
  a 
  length 
  of 
  about 
  0*3. 
  Length 
  of 
  

   head 
  with 
  opercular 
  apparatus 
  equalling 
  the 
  maximum 
  depth 
  of 
  the 
  

   trunk, 
  and 
  occupying 
  about 
  one-fifth 
  of 
  the 
  total 
  length 
  of 
  the 
  fish 
  ; 
  

   maximum 
  depth 
  of 
  trunk 
  twice 
  as 
  great 
  as 
  the 
  width 
  of 
  the 
  caudal 
  

   pedicle. 
  External 
  ornament 
  of 
  head 
  and 
  opercular 
  bones 
  consisting 
  

   of 
  small, 
  sparse 
  tuberculations 
  ; 
  teeth 
  small. 
  Dorsal 
  fin 
  occupying 
  

   nearly 
  half 
  the 
  length 
  of 
  the 
  back, 
  and 
  comprising 
  about 
  25 
  distally- 
  

   bifurcated 
  rays, 
  of 
  which 
  the 
  anterior 
  are 
  much 
  elongated, 
  while 
  

   the 
  others 
  rapidly 
  become 
  much 
  shortened 
  ; 
  pelvic 
  fins 
  arising 
  

   slightly 
  in 
  advance 
  of 
  the 
  middle 
  point 
  between 
  the 
  pectorals 
  and 
  

   the 
  caudal. 
  Scales 
  large 
  and 
  smooth, 
  with 
  delicately 
  pectinated 
  

   hinder 
  border 
  except 
  towards 
  the 
  end 
  of 
  the 
  caudal 
  region. 
  

  

  Form. 
  Sf 
  Loc. 
  Lower 
  Ximmeridgian 
  (Lithographic 
  Stone) 
  : 
  Ba- 
  

   varia. 
  

  

  37029. 
  Full-sized 
  specimen 
  with 
  imperfect 
  head 
  and 
  fins, 
  in 
  counter- 
  

   part 
  ; 
  Solenhofen. 
  The 
  tuberculation 
  of 
  the 
  head 
  and 
  

   opercular 
  bones 
  and 
  post 
  clavicular 
  plates 
  is 
  distinct 
  ; 
  and 
  

   the 
  closely 
  arranged, 
  slightly 
  constricted, 
  smooth 
  ring- 
  

   vertebrge 
  are 
  well 
  shown. 
  The 
  greater 
  part 
  of 
  the 
  

   squamation 
  is 
  also 
  displayed. 
  Htiberlein 
  Coll. 
  

  

  P. 
  6939. 
  Another 
  fine 
  specimen 
  0*25 
  in 
  length, 
  displaying 
  all 
  the 
  

   fins 
  except 
  the 
  anal, 
  and 
  with 
  well-preserved 
  squamation 
  ; 
  

   Eichstadt. 
  By 
  exchange, 
  1893. 
  

  

  