﻿374 
  ACTINOPTERYGII. 
  

  

  Family 
  PACHYCORMID^]. 
  

  

  Trunk 
  fusiform 
  or 
  elongate. 
  Cranial 
  and 
  facial 
  bones 
  moderately 
  

   robust, 
  and 
  opercular 
  apparatus 
  complete 
  ; 
  mandibular 
  suspensorium 
  

   nearly 
  vertical 
  or 
  inclined 
  backwards, 
  and 
  gape 
  of 
  mouth 
  wide 
  ; 
  

   ethmoid 
  fused 
  with 
  vomers 
  and 
  formiug 
  a 
  prominent 
  rostrum 
  ; 
  pre- 
  

   maxillae 
  not 
  in 
  contact 
  mesially 
  ; 
  teeth 
  pointed 
  and 
  conical, 
  usually 
  

   large 
  on 
  part 
  at 
  least 
  of 
  all 
  the 
  dentigerous 
  bones. 
  Notochord 
  

   persistent, 
  sometimes 
  with 
  feeble 
  ossifications 
  in 
  the 
  sheath 
  ; 
  verte- 
  

   bral 
  arches 
  very 
  numerous 
  and 
  closely 
  arranged. 
  Fin-rays 
  slender 
  

   and 
  closely 
  set, 
  articulated 
  arid 
  divided 
  distally 
  ; 
  fulcra 
  minute 
  or 
  

   absent. 
  Dorsal 
  fin 
  short 
  and 
  acuminate. 
  Scales 
  thin 
  and 
  rhombic, 
  

   sometimes 
  with 
  rounded 
  postero 
  -inferior 
  angle. 
  

  

  Synopsis 
  of 
  Genera. 
  

  

  I. 
  Trunk 
  elongate, 
  fusiform. 
  

  

  No 
  ossifications 
  in 
  notochordal 
  sheath 
  ; 
  fin- 
  

   fulcra 
  absent 
  ; 
  pelvic 
  fins 
  present 
  ; 
  

   dorsal 
  fin 
  opposed 
  to 
  much-extended 
  

   anal 
  fin 
  , 
  Sauropsis 
  (p. 
  375). 
  

  

  Ditto, 
  but 
  anal 
  fin 
  not 
  much 
  extended. 
  . 
  . 
  . 
  Prosauropsis 
  (p. 
  376). 
  

  

  Ossified 
  pleurocentra 
  and 
  hypocentra 
  ; 
  fin- 
  

   fulcra 
  minute; 
  pelvic 
  fins 
  present; 
  

   dorsal 
  fin 
  opposed 
  to 
  much-extended 
  

   anal 
  fin 
  Euthynotus 
  (p. 
  377). 
  

  

  Ossifications 
  in 
  notochordal 
  sheath 
  absent 
  

   or 
  rudimentary 
  ; 
  fin-fulcra 
  absent 
  ; 
  

   pelvic 
  fins 
  absent; 
  dorsal 
  in 
  advance 
  

   of 
  anal 
  fin 
  Asthenocormus 
  (p. 
  380). 
  

  

  II. 
  Trunk 
  robust 
  and 
  fusiform. 
  

   Ossifications 
  in 
  notochordal 
  sheath 
  absent 
  

  

  or 
  rudimentary 
  ; 
  principal 
  teeth 
  round 
  

   in 
  section 
  ; 
  pelvic 
  fins 
  absent 
  ; 
  dorsal 
  

   in 
  advance 
  of 
  anal 
  fin, 
  which 
  is 
  not 
  

   much 
  extended 
  Pachycormus 
  (p. 
  380). 
  

  

  No 
  ossifications 
  in 
  notochordal 
  sheath 
  ; 
  

   principal 
  teeth 
  round 
  in 
  section 
  ; 
  ros- 
  

   trum 
  never 
  much 
  produced 
  ; 
  pelvic 
  

   fins 
  small 
  ; 
  dorsal 
  fin 
  arising 
  in 
  ad- 
  

   vance 
  of 
  much-extended 
  anal 
  fin 
  ... 
  . 
  Hypsoeormus 
  (p. 
  390). 
  

  

  Apparently 
  as 
  Hypsoeormus, 
  but 
  principal 
  

   teeth 
  laterally 
  compressed, 
  with 
  sharp 
  

   edges, 
  in 
  complete 
  sockets, 
  and 
  rostrum 
  

   often 
  much 
  produced 
  Protosphyrcena 
  (p. 
  

  

  