﻿EUGNATHID^K. 
  

  

  351 
  

  

  Here, 
  Ann. 
  Sci. 
  Phys. 
  & 
  Nat. 
  Lyon, 
  [2] 
  vol. 
  iii. 
  1850, 
  p. 
  146, 
  and 
  

   Poiss. 
  Foss. 
  Bugey, 
  pt. 
  ii. 
  1873, 
  p. 
  19), 
  from 
  the 
  Lithographic 
  Stone 
  

   (Lower 
  Kimmeridgian) 
  of 
  Ain, 
  France, 
  is 
  also 
  too 
  imperfectly 
  

   described 
  for 
  recognition. 
  

  

  Genus 
  CALLOPTERUS, 
  Thiolliere. 
  

  

  [Bull. 
  Soc. 
  Geol. 
  France, 
  [2] 
  vol. 
  xv. 
  1858, 
  p. 
  784, 
  and 
  Poiss. 
  Foss. 
  

  

  Bugey, 
  pt. 
  ii. 
  1873, 
  p. 
  15.] 
  

  

  A 
  genus 
  apparently 
  differicg 
  only 
  from 
  Caturus 
  in 
  the 
  more 
  

   remote 
  situation 
  of 
  the 
  dorsal 
  fin, 
  which 
  is 
  almost 
  completely 
  

   opposed 
  to 
  the 
  anal. 
  The 
  caudal 
  fin 
  also 
  appears 
  to 
  he 
  less 
  deeply 
  

   forked. 
  

  

  Callopterus 
  agassizi, 
  Thiolliere. 
  

  

  1846. 
  Lepidotus 
  armatus, 
  A. 
  Wagner, 
  Gelehrte 
  Anzeig. 
  k. 
  bay. 
  Akad. 
  

  

  vol. 
  xxii. 
  p. 
  303 
  (inadequate 
  definition). 
  

   1858. 
  Callopterus 
  agassizi, 
  V. 
  Thiolliere, 
  Bull. 
  Soc. 
  G6ol. 
  France, 
  [2] 
  

  

  vol. 
  xv. 
  p. 
  784. 
  

   1863. 
  Lepidotus 
  armatus, 
  A. 
  Wagner, 
  Abh. 
  k. 
  bay. 
  Akad., 
  math.-pkys. 
  

  

  CI, 
  vol. 
  ix. 
  p. 
  620. 
  [Fish 
  ; 
  Palseontological 
  Museum, 
  Munich.] 
  

   1873. 
  Callopterus 
  agassizi, 
  V. 
  Thiolliere, 
  Poiss. 
  Foss. 
  Bugey, 
  pt. 
  ii. 
  

  

  p. 
  15, 
  pi. 
  x. 
  

   1887. 
  Callopterus 
  agassizi, 
  K. 
  A. 
  von 
  Zittel, 
  Handb. 
  Palaeont. 
  vol. 
  iii. 
  

  

  p. 
  231, 
  fig. 
  243. 
  

  

  Type. 
  Fish 
  ; 
  Lyons 
  Museum. 
  

  

  The 
  type 
  species, 
  attaining 
  a 
  length 
  of 
  about 
  0*45. 
  Length 
  of 
  

   head 
  with 
  opercular 
  apparatus 
  somewhat 
  exceeding 
  the 
  maximum 
  

   depth 
  of 
  the 
  trunk 
  and 
  contained 
  about 
  four-and-a-half 
  times 
  in 
  

   the 
  total 
  length 
  of 
  the 
  fish 
  ; 
  depth 
  of 
  caudal 
  pedicle 
  about 
  two- 
  

   thirds 
  as 
  great 
  as 
  the 
  maximum 
  depth 
  of 
  the 
  trunk. 
  Mandibular 
  

   teeth 
  especially 
  stout 
  and 
  closely 
  arranged. 
  Pelvic 
  fins 
  twice 
  as 
  

   distant 
  from 
  the 
  pectorals 
  as 
  from 
  the 
  anal 
  ; 
  dorsal 
  fin, 
  with 
  

   16 
  rays, 
  about 
  half 
  in 
  advance 
  of 
  the 
  anal, 
  which 
  has 
  10 
  rays. 
  

   Bidge-scales 
  of 
  upper 
  caudal 
  lobe 
  much 
  enlarged, 
  extending 
  half- 
  

   way 
  towards 
  the 
  dorsal 
  fin. 
  

  

  Form. 
  § 
  Loc. 
  Lower 
  Kimmeridgian 
  (Lithographic 
  Stone) 
  : 
  Ain, 
  

   France. 
  

  

  Not 
  represented 
  in 
  the 
  Collection. 
  

  

  A 
  stouter 
  small 
  fish 
  0*115 
  in 
  length, 
  from 
  the 
  Lower 
  Kim- 
  

   meridgian 
  bituminous 
  limestone 
  of 
  Orbagnoux, 
  Ain, 
  France, 
  has 
  

   also 
  been 
  referred 
  to 
  this 
  genus 
  under 
  the 
  name 
  of 
  Callopterus 
  

   obesus 
  (H. 
  E. 
  Sauvage, 
  Bull. 
  Soc. 
  Hist. 
  Nat. 
  Autun, 
  vol. 
  vi. 
  1893, 
  

   p. 
  433, 
  pi. 
  ix. 
  fig. 
  1). 
  

  

  