﻿F. 
  B. 
  Loomis 
  — 
  Amphibian 
  from 
  the 
  Eocene. 
  21' 
  

  

  Aet. 
  XIV. 
  — 
  An 
  Amphibian 
  from 
  the 
  Eocene; 
  by 
  F. 
  B. 
  

  

  Loomis. 
  

  

  Among 
  the 
  specimens 
  collected 
  from 
  the 
  Lysite 
  beds 
  of 
  

   the 
  Lower 
  Eocene 
  on 
  Bridger 
  Creek, 
  Wyoming, 
  by 
  the 
  

   Amherst 
  College 
  expedition 
  of 
  1905, 
  is 
  a 
  well-preserved 
  

   skull 
  of 
  an 
  amphibian. 
  It 
  is 
  abont 
  1*4 
  inches 
  long 
  and 
  

   represents 
  an 
  individual 
  about 
  the 
  size 
  of 
  a 
  mudpuppy 
  

   (Necturus). 
  Though 
  Amphibians 
  must 
  have 
  lived 
  in 
  the 
  

   ponds 
  and 
  moist 
  places 
  then, 
  as 
  both 
  before 
  and 
  since 
  

   Eocene 
  times, 
  I 
  believe 
  none 
  has 
  heretofore 
  been 
  found. 
  

   The 
  Lysite 
  represents 
  flood-plain 
  deposits, 
  nnder 
  a 
  

   rather 
  arid 
  climate, 
  as 
  do 
  most 
  of 
  our 
  western 
  Eocene 
  

   epicontinental 
  deposits, 
  but 
  there 
  must 
  have 
  been 
  streams 
  

   and 
  moist 
  places, 
  and 
  this 
  form 
  presumably 
  lived 
  in 
  or 
  

   near 
  some 
  such 
  place. 
  

  

  Unlike 
  such 
  amphibian 
  remains 
  as 
  have 
  been 
  found 
  in 
  

   the 
  Tertiary, 
  this 
  skull 
  can 
  not 
  be 
  referred 
  to 
  any 
  of 
  the 
  

   living 
  genera, 
  though 
  it 
  seems 
  to 
  be 
  clearly 
  one 
  of 
  the 
  

   Caudata, 
  and 
  belongs 
  to 
  the 
  family 
  Salamandridae, 
  and 
  be 
  

   as 
  near 
  to 
  the 
  genus 
  Triton 
  as 
  to 
  any 
  of 
  the 
  living 
  types 
  ; 
  

   but 
  it 
  differs 
  in 
  so 
  many 
  material 
  points 
  that 
  I 
  am 
  not 
  by 
  

   any 
  means 
  confident 
  that 
  it 
  can 
  be 
  considered 
  in 
  any 
  way 
  

   ancestral. 
  It 
  is 
  peculiar 
  among 
  all 
  amphibians 
  in 
  having 
  

   a 
  small 
  splint-like 
  supraoccipital 
  bone, 
  and 
  among 
  cau- 
  

   date 
  types 
  in 
  having 
  a 
  trace 
  of 
  the 
  parietal 
  foramen, 
  

   though 
  the 
  actual 
  opening 
  is 
  closed 
  and 
  plugged 
  with 
  

   bone. 
  The 
  anterior 
  part 
  of 
  the 
  skull 
  is 
  fused 
  into 
  a 
  solid 
  

   roof, 
  and 
  I 
  can 
  not 
  see 
  where 
  the 
  nasal 
  passages 
  opened 
  

   anteriorly, 
  though 
  the 
  interior 
  openings 
  are 
  large. 
  The 
  

   cartilage 
  bones 
  of 
  the 
  posterior 
  part 
  of 
  the 
  skull 
  are 
  

   unusually 
  completely 
  ossified, 
  and 
  the 
  otic 
  region 
  is 
  devel- 
  

   oped 
  so 
  as 
  to 
  form 
  a 
  strong 
  projecting 
  process 
  on 
  the 
  

   ventral 
  side. 
  Most 
  of 
  the 
  skull 
  is 
  preserved 
  except 
  the 
  

   quadrate 
  region, 
  and 
  parts 
  of 
  the 
  squamosum 
  and 
  ptery- 
  

   goid 
  bones. 
  

  

  I 
  have 
  called 
  the 
  form 
  Ototriton 
  solidus 
  gen. 
  and 
  sp. 
  

   nov. 
  The 
  type 
  is 
  in 
  the 
  Amherst 
  College 
  Cabinet, 
  and 
  

   comes 
  from 
  Bridger 
  Creek, 
  Wyoming, 
  from 
  the 
  Lysite 
  

   beds, 
  associated 
  with 
  Eohippus 
  kraspidotus, 
  Phenacodus 
  

   vortmani, 
  Notharctus 
  venticolus, 
  Paramys 
  bicuspis, 
  etc. 
  

  

  The 
  frontals 
  and 
  nasals 
  of 
  both 
  sides 
  are 
  fused 
  

   together 
  and 
  to 
  the 
  maxillae; 
  so 
  that 
  the 
  whole 
  anterior 
  

  

  