﻿218 
  F. 
  B. 
  Loomis 
  — 
  Amphibian 
  fiom 
  the 
  Eocene. 
  

  

  part 
  of 
  the 
  skull 
  is 
  solidly 
  roofed 
  over. 
  The 
  premaxillaa, 
  

   however, 
  were 
  free 
  and 
  must 
  have 
  been 
  small. 
  They 
  are 
  

   lacking, 
  but 
  along 
  the 
  front 
  of 
  the 
  skull 
  are 
  grooves 
  into 
  

   which 
  they 
  set 
  (see 
  fig. 
  1 
  B, 
  P. 
  mx). 
  In 
  this 
  respect, 
  but 
  

   in 
  no 
  other, 
  the 
  skull 
  suggest 
  Necturus. 
  The 
  parietals 
  

   extend 
  back 
  from 
  the 
  frontal 
  s 
  to 
  the 
  rear 
  of 
  the 
  cranium. 
  

   (The 
  line 
  cutting 
  off 
  the 
  rear 
  part 
  of 
  the 
  parietals 
  is 
  not 
  

   a 
  suture 
  but 
  a 
  crack.) 
  These 
  bones 
  are 
  paired, 
  and 
  along 
  

   the 
  middle 
  line 
  in 
  the 
  rear, 
  separated 
  from 
  each 
  other 
  by 
  

   the 
  narrow 
  splint-like 
  supraoccipital 
  bone 
  ; 
  most 
  unusual 
  

   in 
  amphibians, 
  but 
  very 
  clear 
  here. 
  Near 
  the 
  front 
  of 
  

  

  Fig. 
  1. 
  

  

  :p<** 
  

  

  E* 
  oc. 
  

  

  Fig. 
  1. 
  — 
  Skull 
  of 
  Ototriton 
  solidus, 
  natural 
  size; 
  A 
  from 
  above, 
  B 
  from 
  

   below, 
  C 
  from 
  the 
  rear. 
  

  

  An. 
  angulare; 
  Ar. 
  articulare; 
  E. 
  ot. 
  epiotic; 
  Ex. 
  oc. 
  Exoccipital; 
  Fr. 
  

   Frontal; 
  F. 
  M. 
  Foramen 
  Magnum; 
  Mx. 
  Maxilla; 
  0. 
  ot 
  Opisthotic 
  ; 
  0. 
  sp. 
  

   Orbitospenoid; 
  Pal. 
  Palatinum; 
  Par. 
  Parietal; 
  P. 
  mx. 
  Premaxilla 
  facets; 
  

   P. 
  ot. 
  Prootic; 
  P. 
  sp. 
  Parasphenoid 
  ; 
  Pt. 
  Pterygoid; 
  S. 
  oc. 
  Supraoccipital; 
  

   St. 
  Stapes; 
  Vo. 
  Vomer; 
  VII, 
  IX, 
  X 
  Foramena 
  of 
  cranial 
  nerves. 
  

  

  the 
  parietals 
  is 
  a 
  depressed 
  area, 
  in 
  which 
  there 
  is 
  an 
  

   oval 
  groove 
  which 
  can 
  represent 
  nothing 
  but 
  a 
  parietal 
  

   foramen, 
  though 
  it 
  is 
  closed 
  and 
  plugged 
  with 
  bone 
  ; 
  but 
  

   very 
  clearly 
  outlined, 
  especially 
  when 
  magnified. 
  Along 
  

   their 
  posterior 
  border 
  the 
  parietals 
  flare 
  up 
  a 
  little 
  

   m 
  akin 
  g 
  a 
  low 
  crest 
  across 
  the 
  rear 
  of 
  the 
  skull. 
  The 
  

   proximal 
  end 
  of 
  the 
  squamosum 
  bone 
  is 
  present 
  but 
  that 
  

   is 
  all. 
  

  

  The 
  maxillae 
  carry 
  a 
  row 
  of 
  simple 
  conical 
  teeth 
  set 
  

  

  