﻿266 
  ACTINOPTERYGII. 
  

  

  1873), 
  p. 
  292, 
  pi. 
  xix. 
  figs. 
  15, 
  16.— 
  Cretaceous 
  ; 
  Missis- 
  

   sippi 
  and 
  New 
  Jersey. 
  [Fragments 
  of 
  splenial. 
  ] 
  

  

  Pycnodus 
  ricordeaui, 
  H. 
  E. 
  Sauvage, 
  Bull. 
  Soc. 
  Sci. 
  Nat. 
  Yonne, 
  

   vol. 
  xxxiii. 
  pt. 
  ii. 
  (1879), 
  p. 
  40, 
  pi. 
  ii. 
  fig. 
  3.— 
  Upper 
  

   Cretaceous 
  (Aptian) 
  ; 
  Gurgy, 
  Yonne. 
  [Left 
  splenial.] 
  

  

  Pycnodus 
  robustus, 
  J. 
  Leidy, 
  Proc. 
  Acad. 
  Nat. 
  Sci. 
  Philad. 
  1857, 
  

   p. 
  168, 
  and 
  op. 
  cit. 
  1873, 
  p. 
  293, 
  pi. 
  xxxvii. 
  figs. 
  18, 
  19. 
  

   — 
  Cretaceous 
  ; 
  New 
  Jersey. 
  [Detached 
  tooth.] 
  

  

  Pycnodus 
  v 
  avians, 
  J. 
  Cornuel, 
  Bull. 
  Soc. 
  Geol. 
  Prance, 
  [3] 
  vol. 
  v. 
  

   (1877), 
  p. 
  610, 
  pi. 
  xi. 
  fig. 
  7.— 
  Neocomian; 
  Wassy, 
  Haute 
  

   Marne, 
  Prance. 
  [Right 
  splenial.] 
  

  

  Genus 
  COCCODUS, 
  Pictet. 
  

   [Descript. 
  Poiss. 
  Foss. 
  Mont 
  Liban, 
  1850, 
  p. 
  51.] 
  

  

  Trunk 
  comparatively 
  elongated 
  and 
  head 
  relatively 
  very 
  large. 
  

   Head 
  and 
  opercular 
  bones 
  ornamented 
  with 
  tubercles 
  and 
  fine 
  

   ridges, 
  and 
  a 
  large, 
  ascending, 
  laterally 
  compressed, 
  bilaterally 
  

   symmetrical 
  spine 
  fixed 
  upon 
  the 
  occipital 
  region 
  of 
  the 
  cranium 
  ; 
  

   teeth 
  smooth, 
  but 
  indented 
  and 
  partly 
  mammillated, 
  those 
  of 
  the 
  

   vomer 
  in 
  at 
  least 
  three, 
  and 
  those 
  of 
  the 
  splenial 
  apparently 
  in 
  three 
  

   regular 
  series. 
  Neural 
  and 
  haemal 
  arches 
  of 
  axial 
  skeleton 
  of 
  trunk 
  

   robust, 
  but 
  not 
  expanding 
  sufficiently 
  to 
  encircle 
  the 
  notochord. 
  

   Pin-rays 
  stout 
  and 
  well-spaced, 
  articulated 
  and 
  branching 
  distally. 
  

   Pectoral 
  arch 
  much 
  expanded 
  at 
  its 
  inferior 
  extremity, 
  ornamented 
  

   with 
  fine 
  ridges 
  and 
  tuberculations, 
  produced 
  behind 
  into 
  two 
  

   large 
  spines, 
  and 
  forwards 
  into 
  another. 
  [Paired 
  fins 
  unknown 
  ;~j 
  

   dorsal 
  and 
  anal 
  fins 
  not 
  much 
  extended, 
  opposed; 
  caudal 
  fin 
  small 
  

   and 
  fan-shaped, 
  having 
  a 
  convex 
  posterior 
  border. 
  Squamation 
  

   absent. 
  

  

  Coccodus 
  armatus, 
  Pictet. 
  

   [Plate 
  XVI. 
  fig. 
  4.] 
  

  

  1850. 
  Coccodus 
  armatus, 
  F. 
  J. 
  Pictet, 
  Descript. 
  Poiss. 
  Foss. 
  Mont 
  

  

  Liban, 
  p. 
  51, 
  pi. 
  ix. 
  fig. 
  9. 
  

   1887. 
  Coccodus 
  armatus, 
  J. 
  W. 
  Davis, 
  Trans. 
  Roy. 
  Dublin 
  Soc. 
  [2] 
  

  

  vol. 
  iii. 
  p. 
  546, 
  pi. 
  xxx. 
  fig. 
  1. 
  

  

  Type. 
  Vertically 
  crushed 
  head 
  and 
  anterior 
  abdominal 
  region 
  ; 
  

   Geneva 
  Museum. 
  

  

  The 
  type 
  species, 
  attaining 
  a 
  length 
  of 
  about 
  0*18. 
  Head 
  with 
  

   opercular 
  apparatus 
  occupying 
  about 
  one-third 
  of 
  the 
  total 
  length 
  

   of 
  the 
  fish. 
  Occipital 
  spine 
  acuminate, 
  its 
  length 
  considerably 
  

   exceeding 
  twice 
  its 
  maximum 
  breadth, 
  and 
  about 
  equalling 
  two- 
  

  

  