﻿EUGNATHIDiE. 
  315 
  

  

  Genus 
  ALLOLEPIDOTUS, 
  Deecke. 
  

   [Palseontographica, 
  vol. 
  xxxv. 
  1889, 
  p. 
  114.] 
  

  

  Body 
  robust 
  and 
  fusiform, 
  and 
  the 
  atrophied 
  upper 
  caudal 
  lobe 
  

   conspicuous. 
  External 
  head- 
  and 
  opercular 
  bones 
  delicate, 
  more 
  or 
  

   less 
  ornamented 
  with 
  rugae 
  and 
  tuberculations 
  ; 
  snout 
  obtusely 
  

   pointed 
  [maxilla 
  straight?]. 
  Ossifications 
  in 
  the 
  notochordal 
  

   sheath 
  absent 
  or 
  very 
  feeble. 
  Fulcra 
  biserial, 
  relatively 
  large. 
  

   Pelvic 
  fins 
  small; 
  dorsal 
  and 
  anal 
  fins 
  triangular 
  in 
  shape, 
  the 
  

   former 
  arising 
  opposite 
  or 
  immediately 
  behind 
  the 
  pelvic 
  fins 
  ; 
  

   caudal 
  fin 
  moderately 
  forked. 
  Scales 
  thick, 
  mostly 
  smooth, 
  

   sometimes 
  with 
  serrations 
  of 
  the 
  posterior 
  border 
  ; 
  principal 
  

   flank-scales 
  in 
  part 
  deeper 
  than 
  broad, 
  and 
  none 
  of 
  the 
  ventral 
  

   scales 
  much 
  broader 
  than 
  deep 
  ; 
  no 
  enlarged 
  series 
  of 
  dorsal 
  ridge- 
  

   scales. 
  Lateral 
  line 
  inconspicuous. 
  

  

  Allolepidotus 
  rueppelli 
  (Bellotti). 
  

  

  1857. 
  Pholidophorus 
  ruppelii, 
  0. 
  Bellotti, 
  in 
  A. 
  Stoppani, 
  Geol. 
  e 
  

  

  Paleont. 
  Lombardia, 
  p. 
  428. 
  

   1889. 
  Allolepidotus 
  ruppelli, 
  W. 
  Deecke, 
  Palseontogr. 
  vol. 
  xxxv. 
  p. 
  117, 
  

  

  pi. 
  vi. 
  fig. 
  5. 
  

  

  Type. 
  Plaster 
  cast 
  of 
  imperfect 
  fish 
  ; 
  Milan 
  Museum. 
  

  

  The 
  type 
  species, 
  of 
  small 
  size, 
  attaining 
  a 
  length 
  of 
  about 
  0*1. 
  

   Length 
  of 
  head 
  with 
  opercular 
  apparatus 
  much 
  less 
  than 
  the 
  

   maximum 
  depth 
  of 
  the 
  trunk, 
  and 
  contained 
  more 
  than 
  four 
  times 
  

   in 
  the 
  total 
  length. 
  External 
  bones 
  nearly 
  smooth. 
  Dorsal 
  and 
  

   anal 
  fins 
  deeper 
  than 
  long, 
  the 
  former 
  larger 
  than 
  the 
  latter 
  and 
  

   arising 
  behind 
  the 
  pelvic 
  fins. 
  Some 
  of 
  the 
  principal 
  scales 
  of 
  the 
  

   anterior 
  series 
  on 
  the 
  flank 
  nearly 
  twice 
  as 
  deep 
  as 
  broad, 
  and 
  

   those 
  of 
  other 
  series 
  also 
  more 
  or 
  less 
  deepened 
  ; 
  most 
  of 
  the 
  scales 
  

   of 
  the 
  abdominal 
  region 
  conspicuously 
  serrated. 
  

  

  Form. 
  Sf 
  Log. 
  Upper 
  Trias 
  : 
  North 
  Italy. 
  

  

  The 
  only 
  known 
  examples 
  of 
  this 
  species 
  were 
  obtained 
  from 
  the 
  

   black 
  shales 
  of 
  Perledo, 
  on 
  the 
  shore 
  of 
  the 
  Lake 
  of 
  Como, 
  between 
  

   Yarenna 
  and 
  Itegoledo. 
  There 
  are 
  no 
  specimens 
  in 
  the 
  Collection. 
  

  

  Allolepidotus 
  nothosomoides, 
  Deecke. 
  

  

  1889. 
  Allolepidotus 
  nothosomoides, 
  W. 
  Deecke, 
  Palseontogr. 
  vol. 
  xxxv. 
  

   p. 
  118, 
  pi. 
  vi. 
  fig. 
  9. 
  

  

  Type. 
  Nearly 
  complete 
  fish. 
  

  

  A 
  more 
  robust 
  and 
  somewhat 
  larger 
  species 
  than 
  the 
  type. 
  

   Length 
  of 
  head 
  with 
  opercular 
  apparatus 
  nearly 
  equalling 
  the 
  

   maximum 
  depth 
  of 
  the 
  trunk 
  and 
  contained 
  less 
  than 
  four 
  times 
  in 
  

  

  