﻿MACKOSEMIIDvE. 
  183 
  

  

  Petalopteryx 
  elegans 
  (Bassani). 
  

  

  1879. 
  Aphanepygus 
  elegans, 
  F. 
  Bassani, 
  Verhandl. 
  k. 
  k. 
  geol. 
  Reiclis- 
  

  

  anst. 
  p. 
  163. 
  

   1882. 
  Aphanepygus 
  elegans, 
  F. 
  Bassani, 
  Denksclir. 
  k. 
  Akad. 
  Wiss., 
  

  

  math.-naturw. 
  CI. 
  vol. 
  xlv. 
  p. 
  197, 
  pi. 
  i. 
  figs. 
  1-9. 
  

  

  Type. 
  Fish 
  with 
  imperfect 
  fins; 
  Austrian 
  Geological 
  Survey 
  

   Museum, 
  Vienna. 
  

  

  The 
  type 
  species 
  of 
  the 
  so-called 
  genus 
  Aphanepygus, 
  attaining 
  

   a 
  length 
  of 
  about 
  0*12. 
  Length 
  of 
  head 
  with 
  opercular 
  apparatus 
  

   exceeding 
  the 
  maximum 
  depth 
  and 
  contained 
  about 
  five 
  times 
  in 
  

   the 
  total 
  length 
  of 
  the 
  fish 
  to 
  the 
  base 
  of 
  the 
  caudal 
  fin. 
  Tesserae 
  

   on 
  cheek 
  very 
  small, 
  quadrangular 
  and 
  often 
  antero-posteriorly 
  

   elongated. 
  Dorsal 
  fin 
  comprising 
  at 
  least 
  75 
  rays, 
  the 
  longest 
  of 
  

   which 
  are 
  as 
  deep 
  as 
  the 
  maximum 
  depth 
  of 
  the 
  trunk 
  ; 
  pelvic 
  

   fins 
  arising 
  just 
  beyond 
  the 
  end 
  of 
  the 
  first 
  quarter 
  of 
  the 
  trunk. 
  

   Scales 
  small 
  and 
  irregular, 
  smooth, 
  not 
  serrated 
  on 
  the 
  posterior 
  

   margin, 
  and 
  the 
  majority 
  broader 
  than 
  deep. 
  (Bassani.) 
  

  

  Form. 
  Sf 
  Loc. 
  Upper 
  Cretaceous 
  : 
  Island 
  of 
  Lesina, 
  Dalmatia. 
  

  

  Not 
  represented 
  in 
  the 
  Collection. 
  

  

  Genus 
  PROPTERUS, 
  Agassiz. 
  

   [Neues 
  Jahrb. 
  1834, 
  p. 
  386.] 
  

  

  Syn. 
  Rhynchoncodes, 
  0. 
  G. 
  Costa, 
  Atti 
  Accad. 
  Pontan. 
  vol. 
  v. 
  1850, 
  

   p. 
  317. 
  

  

  Trunk 
  irregularly 
  fusiform, 
  the 
  dorsal 
  margin 
  more 
  or 
  less 
  bent 
  

   at 
  the 
  origin 
  of 
  the 
  dorsal 
  fin 
  ; 
  head 
  large, 
  snout 
  acute. 
  Teeth 
  long 
  

   and 
  slender. 
  Notochord 
  invested 
  at 
  least 
  in 
  part 
  with 
  very 
  delicate 
  

   pleurocentra 
  and 
  hypocentra 
  or 
  ring-vertebras. 
  Fins 
  consisting 
  of 
  

   distally 
  bifurcating 
  rays 
  ; 
  paired 
  fins 
  of 
  moderate 
  size, 
  without 
  

   fulcra 
  ; 
  median 
  fins 
  very 
  large, 
  the 
  dorsal 
  extending 
  more 
  than 
  

   half 
  the 
  length 
  of 
  the 
  back 
  and 
  divided 
  into 
  two 
  portions, 
  the 
  anal 
  

   fin 
  short 
  and 
  deep, 
  and 
  the 
  caudal 
  deeply 
  forked 
  ; 
  dorsal 
  fin 
  with 
  

   basal 
  fulcra, 
  the 
  anal 
  and 
  caudal 
  fringed 
  with 
  fulcra. 
  Scales 
  

   covering 
  the 
  whole 
  of 
  the 
  trunk, 
  in 
  regular 
  series, 
  united 
  by 
  peg- 
  

   and-socket 
  articulation, 
  and 
  usually 
  pectinated 
  or 
  denticulated 
  at 
  

   the 
  hinder 
  border 
  ; 
  the 
  principal 
  flank-scales 
  somewhat 
  deeper 
  than 
  

   broad, 
  none 
  of 
  the 
  ventral 
  scales 
  much 
  broader 
  than 
  deep 
  ; 
  no 
  en- 
  

   larged 
  ridge- 
  scales. 
  

  

  Propterus 
  microstomias, 
  Agassiz. 
  

  

  1834. 
  Propterus 
  microstomas, 
  L. 
  Agassiz, 
  Neues 
  Jahrb. 
  p. 
  386. 
  

   1833-44. 
  Notagogus 
  zieteni, 
  L. 
  Agassiz, 
  Poiss. 
  Foss. 
  vol. 
  ii. 
  pt. 
  i. 
  

  

  