﻿64 
  ACTINOPTEKYGII. 
  

  

  The 
  names 
  of 
  Semionotus 
  balsami, 
  brevis, 
  dubius, 
  inermis, 
  and 
  

   trotti 
  l 
  are 
  given 
  by 
  C. 
  Bellotti 
  (in 
  A. 
  Stoppani, 
  Studii 
  Geol. 
  e 
  Paleont. 
  

   Lombardia, 
  1857, 
  pp. 
  422-427) 
  to 
  fishes 
  of 
  uncertain 
  affinities 
  from 
  

   the 
  Upper 
  Trias 
  of 
  Perledo, 
  Como. 
  Another 
  unsatisfactorily 
  deter- 
  

   mined 
  species 
  is 
  also 
  named 
  Semionotus 
  bellotti, 
  E. 
  Riippell, 
  in 
  

   A. 
  Stoppani, 
  ibid. 
  p. 
  425. 
  

  

  It 
  still 
  remains 
  to 
  be 
  proved 
  that 
  the 
  so-called 
  Archceosemionotus 
  

   connectens 
  (W. 
  Deecke, 
  Palaeontogr. 
  vol. 
  xxxv. 
  1889, 
  p. 
  121, 
  pi. 
  vi. 
  

   fig. 
  3), 
  from 
  the 
  Trias 
  of 
  Perledo, 
  Como, 
  is 
  not 
  founded 
  on 
  an 
  

   imperfect 
  example 
  of 
  Semionotus. 
  The 
  unique 
  type 
  specimen, 
  in 
  

   the 
  Senckenberg 
  Institute, 
  Frankfort, 
  has 
  probably 
  lost 
  its 
  squama- 
  

   tion 
  by 
  accident. 
  

  

  The 
  imperfect 
  trunk 
  of 
  a 
  fish 
  from 
  the 
  Upper 
  Muschelkalk 
  of 
  the 
  

   neighbourhood 
  of 
  Jena, 
  apparently 
  related 
  to 
  Semionotus 
  and 
  its- 
  

   allies, 
  is 
  named 
  Dolichopterus 
  volitans 
  by 
  G. 
  Compter, 
  Zeitschr. 
  f. 
  

   Naturw. 
  vol. 
  lxiv. 
  (1891), 
  p. 
  41, 
  pi. 
  i. 
  figs. 
  1-6. 
  It 
  is 
  described 
  as 
  

   characterized 
  by 
  much-enlarged 
  pectoral 
  fins, 
  and 
  by 
  a 
  compara- 
  

   tively 
  short 
  dorsal 
  opposed 
  to 
  an 
  extended 
  anal. 
  Another 
  imperfect 
  

   fish, 
  apparently 
  of 
  almost 
  the 
  same 
  systematic 
  position, 
  from 
  the 
  

   Upper 
  Muschelkalk 
  of 
  Elm, 
  Brunswick, 
  is 
  described 
  and 
  figured 
  

   without 
  name 
  by 
  W. 
  Dames, 
  Palaeont. 
  Abhandl. 
  vol. 
  iv. 
  (1888), 
  

   p. 
  173, 
  pi. 
  xvia. 
  fig. 
  10. 
  

  

  Genus 
  APHNELEPIS, 
  A. 
  S. 
  Woodward. 
  

  

  [Described 
  in 
  forthcoming 
  Mem. 
  Geol. 
  Surv. 
  N. 
  S. 
  Wales, 
  

   Palaeont. 
  no. 
  9.] 
  

  

  Trunk 
  laterally 
  compressed 
  and 
  deeply 
  fusiform. 
  Head 
  of 
  mode- 
  

   rate 
  size 
  with 
  acuminate 
  snout, 
  and 
  more 
  or 
  less 
  ornamented 
  with 
  

   rugae 
  and 
  tubercles 
  ; 
  marginal 
  teeth 
  small, 
  stout, 
  and 
  almost 
  conical, 
  

   closely 
  arranged 
  : 
  inner 
  teeth 
  nearly 
  granular. 
  Notochord 
  per- 
  

   sistent, 
  sometimes 
  with 
  small 
  hypocentra 
  and 
  pleurocentra 
  in 
  the 
  

   caudal 
  region 
  ; 
  ribs 
  long. 
  Eulcra 
  conspicuous 
  on 
  all 
  the 
  fins. 
  

   Pectoral 
  fins 
  of 
  moderate 
  size, 
  somewhat 
  larger 
  than 
  the 
  pelvic 
  pair, 
  

   which 
  are 
  well 
  developed 
  ; 
  dorsal 
  and 
  anal 
  fins 
  acuminate 
  and 
  short- 
  

   based, 
  the 
  former 
  almost 
  or 
  completely 
  in 
  advance 
  of 
  the 
  latter 
  ; 
  

   caudal 
  fin 
  forked. 
  Scales 
  all 
  rhombic, 
  thin 
  on 
  the 
  abdominal, 
  still 
  

   thinner 
  on 
  the 
  caudal 
  region 
  ; 
  those 
  of 
  the 
  flank 
  deeper 
  than 
  

   broad, 
  those 
  of 
  the 
  dorsal 
  and 
  ventral 
  borders 
  about 
  as 
  deep 
  as 
  

   broad 
  ; 
  ridge-scales 
  not 
  enlarged. 
  

  

  1 
  Described 
  as 
  Lepidotus 
  trotti 
  by 
  Balsamo-Crivelli, 
  Ann. 
  Polytecn. 
  Milano, 
  

   May 
  1839. 
  

  

  