﻿PB.OLIDOPHORIDJE. 
  447 
  

  

  beyond 
  the 
  annular 
  stage 
  ; 
  ribs 
  delicate 
  ; 
  no 
  fused 
  or 
  expanded 
  

   haemal 
  arches 
  at 
  the 
  base 
  of 
  the 
  tail. 
  Intermuscular 
  bones 
  absent. 
  

   Em-fulcra 
  present, 
  but 
  usually 
  small; 
  dorsal 
  and 
  anal 
  fins 
  small, 
  

   the 
  former 
  above 
  or 
  behind 
  the 
  pelvic 
  fins. 
  Scales 
  ganoid, 
  more 
  or 
  

   less 
  rhombic, 
  but 
  deeply 
  overlapping, 
  and 
  the 
  hinder 
  margin 
  often 
  

   somewhat 
  rounded. 
  

  

  Synopsis 
  of 
  Genera. 
  

  

  I. 
  Flank-scales 
  united 
  by 
  peg-and-socket, 
  not 
  

  

  excessively 
  deepened. 
  

   Pectoral 
  and 
  pelvic 
  fins 
  small 
  ; 
  dorsal 
  in 
  

  

  advance 
  of 
  anal 
  Pholidophorus 
  (p. 
  447). 
  

  

  Pectoral 
  fins 
  greatly 
  enlarged, 
  and 
  pelvic 
  fins 
  

  

  small 
  ; 
  dorsal 
  opposed 
  to 
  anal 
  Thoracopterus 
  (p. 
  478) 
  . 
  

  

  II. 
  Flank-scales 
  united 
  by 
  peg-and- 
  socket, 
  one 
  

  

  series 
  excessively 
  deepened. 
  

   Pelvic 
  fins 
  absent 
  ; 
  dorsal 
  opposed 
  to 
  anal 
  ; 
  

  

  ventral 
  scales 
  broader 
  than 
  deep 
  ; 
  lateral 
  

  

  line 
  along 
  deepened 
  scales 
  Pholidopleurus 
  (p. 
  479). 
  

  

  Pelvic 
  fins 
  small 
  ; 
  dorsal 
  in 
  advance 
  of 
  anal 
  ; 
  

  

  ventral 
  scales 
  as 
  broad 
  as 
  deep 
  ; 
  lateral 
  

  

  line 
  along 
  deepened 
  scales 
  Peltopleurus 
  (p. 
  481). 
  

  

  Pelvic 
  fins 
  small 
  ; 
  dorsal 
  opposed 
  to 
  anal 
  ; 
  

  

  ventral 
  scales 
  about 
  as 
  broad 
  as 
  deep 
  ; 
  

  

  lateral 
  line 
  deflected 
  to 
  upper 
  series 
  of 
  

  

  ventral 
  scales 
  Pleuropholis 
  (p. 
  482). 
  

  

  III. 
  Flank-scales 
  not 
  united 
  by 
  peg-and-socket, 
  

   not 
  excessively 
  deepened. 
  

  

  Pectoral 
  and 
  pelvic 
  fins 
  of 
  moderate 
  size 
  ; 
  

  

  dorsal 
  and 
  anal 
  opposed; 
  scales 
  thin 
  . 
  . 
  Archceomcene 
  (p. 
  488). 
  

  

  IV. 
  Flank-scales 
  unknown. 
  

  

  Fins 
  with 
  long 
  slender 
  fulcra, 
  and 
  dorsal 
  in 
  

   advance 
  of 
  anal 
  ; 
  large 
  caudal 
  ridge- 
  

   scales 
  Ceramurus 
  (p. 
  489). 
  

  

  Genus 
  PHOLIDOPHORUS, 
  Agassiz. 
  

   [Neues 
  Jahrb. 
  1832, 
  p. 
  145.] 
  

   Syn. 
  (?) 
  Microps, 
  L. 
  Agassiz, 
  Poiss. 
  Foss. 
  vol. 
  ii. 
  pt. 
  i. 
  1833, 
  p. 
  10. 
  ' 
  (JjeJi^-tti 
  Q^ 
  

  

  Trunk 
  not 
  much 
  deepened, 
  and 
  head 
  relatively 
  large. 
  External 
  

   bones 
  smooth 
  or 
  delicately 
  ornamented 
  with 
  rugae 
  and 
  tubercula- 
  

   tions 
  ; 
  sensory 
  canal 
  on 
  suborbital 
  and 
  preorbital 
  plates 
  branched 
  ; 
  

   maxilla 
  more 
  or 
  less 
  arched, 
  the 
  oral 
  margin 
  convex 
  and 
  provided 
  

   with 
  minute 
  teeth 
  ; 
  mandibular 
  teeth 
  larger, 
  but 
  still 
  minute 
  and 
  

   arranged 
  in 
  a 
  single 
  series. 
  Preoperculum 
  broad 
  mesially 
  and 
  

   marked 
  with 
  slight 
  radiating 
  furrows 
  ; 
  suboperculum 
  large, 
  but 
  

  

  