﻿PACHYCORMID.E. 
  

  

  391 
  

  

  in 
  length 
  and 
  are 
  not 
  branched 
  distally 
  ; 
  pelvic 
  fins 
  small 
  ; 
  dorsal 
  fin 
  

   partly 
  or 
  completely 
  in 
  advance 
  of 
  the 
  anal, 
  which 
  is 
  much 
  extended 
  ; 
  

   caudal 
  fin 
  very 
  deeply 
  forked. 
  Scales 
  small 
  and 
  deeply 
  imbricating, 
  

   those 
  of 
  the 
  ventral 
  aspect 
  much 
  broader 
  than 
  deep 
  ; 
  lateral 
  line 
  

   inconspicuous. 
  

  

  So 
  far 
  as 
  known, 
  the 
  osteology 
  of 
  this 
  genus 
  is 
  almost 
  identical 
  

   with 
  that 
  of 
  Pachycormus, 
  as 
  already 
  described; 
  but 
  there 
  is 
  a 
  

   distinct 
  premaxilla 
  and 
  the 
  dentition 
  is 
  much 
  more 
  powerful. 
  The 
  

   same 
  characteristic 
  arrangement 
  of 
  the 
  suborbital 
  and 
  circumorbital 
  

   bones 
  is 
  observable; 
  the 
  sclerotic 
  is 
  also 
  well-ossified; 
  and 
  the 
  

   posteriorly 
  -placed 
  supramaxilla 
  is 
  identical 
  in 
  the 
  two 
  genera. 
  The 
  

   maxilla 
  does 
  not 
  articulate 
  directly 
  with 
  the 
  cranium 
  or 
  pterygo- 
  

   palatine 
  arcade, 
  but 
  is 
  suturally 
  united 
  with 
  the 
  premaxilla 
  ; 
  and 
  

   the 
  latter 
  element 
  is 
  apposed 
  to 
  an 
  extended 
  groove 
  in 
  the 
  lateral 
  

   ethmoidal 
  region 
  along 
  its 
  narrow 
  antero-superior 
  border. 
  The 
  

   vomers 
  are 
  clearly 
  shown 
  to 
  be 
  fused 
  with 
  the 
  mesethmoid 
  ; 
  and 
  

   their 
  pair 
  of 
  large 
  teeth 
  is 
  directly 
  opposed 
  to 
  a 
  similar 
  pair 
  in 
  the 
  

   splenials. 
  The 
  latter 
  elements 
  are 
  much 
  thickened 
  where 
  they 
  

   meet 
  in 
  the 
  mandibular 
  symphysis 
  ; 
  but 
  they 
  rapidly 
  taper 
  back- 
  

   wards, 
  again 
  expanding 
  in 
  the 
  hinder 
  half 
  of 
  the 
  ramus 
  into 
  a 
  thin 
  

   laminar 
  plate 
  apparently 
  covering 
  the 
  whole 
  of 
  the 
  inner 
  face 
  of 
  

   the 
  jaw 
  and 
  armed 
  with 
  minute, 
  almost 
  granular 
  teeth. 
  The 
  teeth 
  

   of 
  the 
  dentary 
  are 
  borne 
  on 
  a 
  thickened 
  ledge 
  on 
  the 
  inner 
  face 
  of 
  

   the 
  bone. 
  Between 
  the 
  mandibular 
  rami 
  there 
  is 
  a 
  large, 
  azygous 
  

   gular 
  plate, 
  followed 
  by 
  a 
  numerous 
  series 
  of 
  short 
  branchiostegal 
  

   rays. 
  The 
  only 
  important 
  differences 
  in 
  the 
  trunk 
  seem 
  to 
  be, 
  the 
  

   presence 
  of 
  small 
  pelvic 
  fins 
  and 
  the 
  elongation 
  of 
  the 
  anal 
  fin. 
  

  

  Hypsocormus 
  insignis, 
  Wagner. 
  

   [Plate 
  XIV. 
  fig. 
  1.] 
  

  

  1860. 
  Hypsocormus 
  insignis, 
  A. 
  Wagner, 
  Gelehrte 
  Anzeig. 
  k. 
  bay. 
  

  

  Akad. 
  Wiss. 
  vol. 
  1. 
  p. 
  221. 
  

   1863. 
  Hypsocormus 
  insignis, 
  A. 
  Wagner, 
  Abh. 
  k. 
  bay. 
  Akad. 
  Wiss., 
  

  

  math.-phys. 
  CI. 
  vol. 
  ix. 
  p. 
  677. 
  

   1881. 
  Hypsocormus 
  insignis, 
  B. 
  Vetter, 
  Mittheil. 
  k. 
  mineral.-geol. 
  Mus. 
  

  

  Dresden, 
  pt. 
  iv. 
  p. 
  95. 
  

   1887. 
  Hypsocormus 
  insignis^ 
  K. 
  A. 
  von 
  Zittel, 
  Handb. 
  Palaeont. 
  vol. 
  hi. 
  

  

  p. 
  226, 
  woodc. 
  fig. 
  239. 
  

  

  Type. 
  Imperfect 
  fish 
  ; 
  Palaeontologieal 
  Museum, 
  Munich. 
  

  

  The 
  type 
  species, 
  attaining 
  a 
  length 
  of 
  about 
  07. 
  Length 
  of 
  

   head 
  with 
  opercular 
  apparatus 
  equalling 
  about 
  one-quarter 
  of 
  the 
  

   total 
  length 
  to 
  the 
  base 
  of 
  the 
  caudal 
  fin, 
  and 
  less 
  than 
  the 
  maxi- 
  

   mum 
  depth 
  of 
  the 
  trunk. 
  Snout 
  short 
  and 
  obtuse, 
  and 
  external 
  

  

  