﻿sehionotid^. 
  139 
  

  

  A 
  small 
  species 
  attaining 
  a 
  length 
  of 
  about 
  0*2. 
  Form 
  variable, 
  

   but 
  maximum 
  depth 
  of 
  trunk 
  usually 
  less 
  than 
  its 
  length 
  (exclusive 
  

   of 
  the 
  caudal 
  fin) 
  in 
  the 
  proportion 
  of 
  about 
  6 
  to 
  7, 
  and 
  equalling 
  

   approximately 
  three 
  and 
  a 
  half 
  times 
  the 
  depth 
  of 
  the 
  caudal 
  pedicle. 
  

   Head 
  with 
  opercular 
  apparatus 
  occupying 
  nearly 
  one-quarter 
  of 
  the 
  

   total 
  length 
  of 
  the 
  fish 
  ; 
  the 
  external 
  bones 
  almost 
  smooth, 
  with 
  

   very 
  few 
  small 
  sparse 
  tubercles, 
  and 
  the 
  operculum 
  also 
  exhibiting 
  

   reticulated 
  markings. 
  Marginal 
  teeth 
  bicuspid 
  and 
  robust. 
  Scales 
  

   smooth, 
  and 
  the 
  hinder 
  border 
  not 
  serrated. 
  

  

  The 
  young 
  of 
  Dapedius 
  orbis 
  being 
  as 
  yet 
  unknown, 
  it 
  still 
  remains 
  

   uncertain 
  whether 
  or 
  not 
  the 
  small 
  fishes 
  described 
  as 
  D. 
  dorsalis 
  

   should 
  be 
  thus 
  interpreted. 
  

  

  Form. 
  Sf 
  Loc. 
  Lower 
  Lias 
  : 
  " 
  Gloucestershire 
  " 
  and 
  Leicestershire. 
  

  

  P. 
  7421. 
  Type 
  specimen 
  figured 
  by 
  Agassiz, 
  loc. 
  cit. 
  pi. 
  xxi. 
  figs. 
  1, 
  2; 
  

   said 
  to 
  have 
  been 
  " 
  found 
  in 
  limestone 
  near 
  Byrford, 
  

   Gloucestershire." 
  Possibly 
  the 
  locality 
  intended 
  is 
  Burford 
  

   Signet, 
  Oxfordshire, 
  where 
  the 
  Lower 
  Lias 
  occurs. 
  

  

  Old 
  Collection. 
  

  

  P. 
  467. 
  Impression 
  of 
  fish 
  imperfect 
  dorsally, 
  figured 
  by 
  Agassiz, 
  

   loc. 
  cit. 
  pi. 
  xxi. 
  a. 
  fig. 
  1 
  ; 
  labelled 
  " 
  Gloucester." 
  

  

  Egerton 
  Coll. 
  

  

  P. 
  1553, 
  P. 
  3532. 
  Typical 
  specimen 
  in 
  counterpart, 
  labelled 
  by 
  

   Agassiz, 
  and 
  showing 
  bicuspid 
  marginal 
  teeth 
  ; 
  Barrow- 
  

   on-Soar, 
  Leicestershire. 
  Egerton 
  Sf 
  EnnisMllen 
  Colls. 
  

  

  P. 
  1552. 
  A 
  much 
  fractured 
  fish, 
  the 
  maximum 
  depth 
  of 
  the 
  trunk 
  

   0-077 
  and 
  its 
  length 
  (without 
  caudal 
  fin) 
  0*088 
  ; 
  Barrow- 
  

   on-Soar. 
  Egerton 
  Coll. 
  

  

  P. 
  1552 
  a. 
  A 
  large 
  specimen 
  0*2 
  in 
  length, 
  having 
  the 
  trunk 
  as 
  

   deep 
  as 
  long 
  ; 
  Barrow-on-Soar. 
  Tubercles 
  occur 
  on 
  the 
  

   cranial 
  roof, 
  and 
  there 
  are 
  bicuspid 
  teeth 
  in 
  the 
  jaw. 
  

  

  Egerton 
  Coll. 
  

  

  P. 
  3530 
  x, 
  P. 
  3531. 
  Comparatively 
  deep-bodied 
  fish, 
  0-13 
  in 
  length, 
  

   in 
  counterpart 
  ; 
  Barrow-on-Soar. 
  One 
  side 
  of 
  the 
  speci- 
  

   men 
  is 
  labelled 
  " 
  Tetragonolepis 
  monilifer, 
  Agass.," 
  the 
  

   other 
  " 
  Tetragonolepis 
  striolatus, 
  Agass.," 
  both 
  in 
  Agassiz' 
  

   handwriting. 
  EnnisMllen 
  Coll. 
  

  

  P. 
  3530. 
  Pour 
  specimens 
  variously 
  imperfect; 
  Barrow-on-Soar. 
  

  

  EnnisMllen 
  Coll. 
  

  

  