﻿246 
  

  

  THE 
  EXTINCT 
  VERTEBRATE 
  ANIMALS 
  

  

  and 
  Tynet. 
  Outside 
  the 
  Moray 
  Firth 
  area 
  it 
  is 
  common 
  in 
  

   Orkney, 
  and 
  at 
  Achanarras 
  in 
  Caithness. 
  

  

  Pterichthys 
  productus, 
  Agassiz. 
  

  

  Syn. 
  Pt. 
  cancriformis, 
  Ag., 
  1844. 
  

  

  Found 
  in 
  the 
  same 
  localities 
  as 
  Pt. 
  Milleri. 
  I 
  have 
  suggested 
  (49, 
  p. 
  

   284) 
  that 
  the 
  differences 
  between 
  the 
  two 
  forms 
  may 
  be 
  of 
  a 
  

   sexual 
  nature. 
  

  

  Pterichthys 
  oblongus, 
  Agassiz, 
  1844. 
  

  

  Also 
  in 
  the 
  same 
  localities 
  as 
  the 
  two 
  preceding, 
  but 
  not 
  so 
  common. 
  

  

  Sub-class 
  DIPNOI. 
  

  

  Order 
  SIRENOIDEI. 
  

   Family 
  CTENODONTIDjE. 
  

  

  Genus 
  DIPTERUS, 
  Sedgw. 
  and 
  Murchison. 
  

   Dipterus 
  Valenciennesii, 
  Sedgw. 
  and 
  Murchison, 
  1828. 
  

   Syn. 
  D. 
  macropygopterus, 
  Sedgw. 
  and 
  Murch. 
  ; 
  D. 
  brachygopterus, 
  Sedgw. 
  

   and 
  Murch. 
  ; 
  Polyphractus 
  platycephalus, 
  Ag. 
  • 
  Dipterus 
  platyceplmlus, 
  

   Pander 
  ; 
  D. 
  macrolepidotus, 
  Ag., 
  non 
  Sedgw. 
  and 
  Murch. 
  

   (Restored 
  figure 
  PI. 
  ii. 
  fig. 
  3.) 
  

   Cromarty 
  ; 
  Nairnside, 
  near 
  Inverness 
  ; 
  Lethen 
  Bar 
  ; 
  Tynet 
  Burn. 
  

   Though 
  abundant 
  in 
  the 
  Caithness 
  flags, 
  Dipterus 
  Valenciennesii 
  is 
  

   very 
  rare 
  in 
  the 
  Moray 
  Firth 
  nodules. 
  

  

  In 
  the 
  way 
  of 
  ' 
  restoration 
  ' 
  this 
  interesting 
  fish 
  has 
  not 
  met 
  

   with 
  the 
  best 
  of 
  treatment. 
  Agassiz's 
  figure 
  (29, 
  tab. 
  E, 
  fig. 
  1), 
  

   so 
  repeatedly 
  copied 
  into 
  text-books, 
  has 
  scarcely 
  the 
  remotest 
  

   resemblance 
  to 
  the 
  creature 
  in 
  question. 
  Pander's 
  restoration 
  1 
  

   was 
  an 
  immense 
  advance, 
  a 
  really 
  faithful 
  attempt 
  to 
  represent 
  

   the 
  facts 
  of 
  nature 
  as 
  he 
  saw 
  them, 
  and 
  is 
  in 
  truth 
  much 
  more 
  

   correct 
  than 
  that 
  given 
  quite 
  recently 
  by 
  Mr. 
  Bashford 
  Dean, 
  2 
  

   which 
  is 
  in 
  many 
  respects 
  quite 
  inaccurate. 
  My 
  present 
  figure, 
  

   PI. 
  ii. 
  fig. 
  3, 
  has 
  been 
  carefully 
  taken 
  from 
  the 
  best 
  Caithness 
  

   specimens 
  in 
  the 
  Edinburgh 
  Museum. 
  

  

  1 
  Die 
  Ctenodipterinen 
  des 
  devonischen 
  Sy 
  sterns. 
  St. 
  Petersburg, 
  1858. 
  Tab. 
  2, 
  

   fig. 
  1. 
  

  

  2 
  Fishes, 
  Living 
  and 
  Fossil. 
  New 
  York, 
  1895. 
  Fig. 
  123. 
  

  

  