﻿.50 
  

  

  ACTINOPTEKrGII. 
  

  

  Synopsis 
  of 
  Genera. 
  

  

  I. 
  Trunk 
  regularly 
  and 
  deeply 
  fusiform. 
  

  

  (a) 
  Teeth 
  all 
  styliform. 
  or 
  reduced 
  within 
  

  

  the 
  mouth. 
  

  

  Dorsal 
  fin 
  arising 
  well 
  in 
  advance 
  of 
  

   anal 
  ; 
  no 
  enlarged 
  ridge-scales 
  . 
  . 
  

  

  Dorsal 
  fin 
  arising 
  well 
  in 
  advance 
  of 
  

   anal 
  ; 
  dorsal 
  ridge-scales 
  prominent 
  

  

  Dorsal 
  fin 
  arising 
  well 
  in 
  advance 
  of 
  

   anal; 
  scales 
  comparatively 
  thin, 
  

   and 
  much 
  the 
  thinnest 
  on 
  caudal 
  

   region 
  ; 
  no 
  enlarged 
  ridge-scales 
  . 
  . 
  

  

  [Genus 
  known 
  only 
  by 
  detached 
  scales, 
  

   which 
  are 
  much 
  deeper 
  than 
  

   broad, 
  with 
  a 
  narrow 
  overlapped 
  

   margin, 
  a 
  large 
  peg-and-socket 
  

   articulation, 
  and 
  no 
  sharp 
  inner 
  

   keel 
  ; 
  hinder 
  border 
  denticulated. 
  

  

  Dorsal 
  fin 
  opposed 
  to 
  anal 
  ; 
  dorsal 
  and 
  

   ventral 
  ridge-scales 
  prominent 
  . 
  . 
  

  

  (b) 
  Marginal 
  teeth 
  styliform 
  ; 
  inner 
  teeth 
  

  

  stouter 
  and 
  mostly 
  tritoral. 
  

  

  [Genus 
  known 
  only 
  by 
  marginal 
  teeth, 
  

   of 
  which 
  crown 
  is 
  expanded 
  to 
  

   chisel- 
  or 
  gouge-shaped 
  edge 
  .... 
  

  

  Dorsal 
  fin 
  arising 
  well 
  in 
  advance 
  of 
  

   the 
  anal, 
  both 
  these 
  fins 
  much 
  

   elevated 
  and 
  fringed 
  with 
  fulcra 
  

   which 
  are 
  scarcely 
  enlarged 
  at 
  

   the 
  base 
  ; 
  angles 
  of 
  overlapped 
  

   margin 
  of 
  scales 
  not 
  produced 
  . 
  . 
  

  

  Dorsal 
  fin 
  arising 
  well 
  in 
  advance 
  of 
  

  

  Acentrophorus 
  (p. 
  51). 
  

   Semionotus 
  (p. 
  55). 
  

  

  Aphnelepis 
  (p. 
  64). 
  

  

  Serrolepis 
  (p. 
  65).] 
  

   Pristisomus 
  (p. 
  66). 
  

  

  Sargodon 
  (p. 
  67).] 
  

  

  Colobodus 
  (p. 
  68). 
  

  

  excessively 
  elevated, 
  but 
  with 
  a 
  

   cluster 
  of 
  enlarged 
  fulcra 
  at 
  the 
  

   base 
  ; 
  angles 
  of 
  overlapped 
  mar- 
  

   gin 
  of 
  scales 
  produced 
  forwards 
  ; 
  

  

  no 
  gular 
  plate 
  Lepidotus 
  (p. 
  77). 
  

  

  II. 
  Trunk 
  much 
  deepened, 
  often 
  irregular 
  in 
  

   form. 
  

  

  Trunk 
  very 
  deeply 
  fusiform 
  or 
  regu- 
  

   larly 
  cycloidal; 
  teeth 
  stout 
  and 
  

   styliform, 
  clustered 
  within 
  the 
  

   mouth 
  ; 
  dorsal 
  fin 
  much 
  extended 
  

   and 
  anal 
  opposed 
  to 
  its 
  hinder 
  

   half 
  ; 
  all 
  scales 
  rhombic, 
  with 
  

   feeble 
  inner 
  rib; 
  ridge-scales 
  in- 
  

   conspicuous 
  , 
  , 
  Dapedius 
  (p. 
  128). 
  

  

  