﻿1G 
  SUPPLEMENT 
  TO 
  THE 
  EXTINCT 
  BATRACHIA 
  

  

  COCYTINUS, 
  Cope. 
  

   Proceed. 
  Amer. 
  Philos. 
  Soc, 
  1871, 
  p. 
  177. 
  

  

  Vertebrae 
  and 
  ribs 
  osseous 
  ; 
  anterior 
  limbs, 
  thoracic 
  shields 
  and 
  abdominal 
  arma- 
  

   ture 
  apparently 
  wanting. 
  Teeth 
  on 
  the 
  premaxillary 
  bone, 
  none 
  on 
  the 
  maxillary. 
  

   Hyoid 
  elements 
  largely 
  developed. 
  An 
  axial 
  hyal 
  with 
  basihyal 
  on 
  each 
  side, 
  closely 
  

   united 
  with 
  the 
  corresponding 
  ceratohyal, 
  at 
  the 
  end 
  of 
  which 
  is 
  an 
  element 
  in 
  the 
  

   position 
  of 
  a 
  stylohyal. 
  Haemal 
  or 
  basal 
  branchihyals 
  three, 
  the 
  anterior 
  two 
  each 
  

   supporting 
  one 
  pleural 
  branchihyal, 
  and 
  the 
  third 
  supporting 
  one 
  also. 
  The 
  first 
  or 
  

   anterior 
  haemal 
  branchihyal 
  on 
  the 
  inner 
  side 
  of 
  the 
  ceratohyal, 
  approaching 
  the 
  

   median 
  line, 
  and 
  with 
  elongate 
  pleural 
  element. 
  Urohyal 
  not 
  seen. 
  

  

  Such 
  are 
  the 
  characters 
  of 
  a 
  genus, 
  whose 
  affinities 
  are 
  interesting 
  but 
  somewhat 
  

   obscure. 
  The 
  hyoid 
  apparatus 
  is 
  better 
  developed 
  than 
  in 
  any 
  other 
  here 
  described, 
  

   but 
  it 
  is 
  by 
  no 
  means 
  certain 
  that 
  it 
  was 
  branchiferous 
  at 
  maturity, 
  nor 
  does 
  this 
  

   character 
  on 
  the 
  other 
  hand 
  render 
  it 
  certain 
  that 
  the 
  animal 
  is 
  the 
  larva 
  of 
  one 
  of 
  the 
  

   other 
  forms 
  here 
  described. 
  The 
  well 
  ossified 
  ribs 
  and 
  vertebrae 
  are 
  favorable, 
  

   though 
  not 
  conclusive 
  evidence 
  for 
  adult 
  age, 
  while 
  the 
  structure 
  of 
  the 
  hyoid 
  appa- 
  

   ratus 
  is 
  more 
  like 
  that 
  of 
  the 
  gilless 
  genera 
  Ampliiuma 
  and 
  Pro'onopsis, 
  than 
  it 
  is 
  

   like 
  the 
  branchiferous 
  genera 
  Siren 
  and 
  Necturus, 
  or 
  the 
  branchiate 
  young 
  of 
  Sala- 
  

   manders. 
  Thus 
  it 
  differs 
  from 
  Proteus 
  in 
  the 
  presence 
  of 
  the 
  first 
  axial 
  hyal 
  and 
  the 
  

   two 
  first 
  basihyals, 
  from 
  this 
  genus 
  and 
  Necturus 
  in 
  the 
  possession 
  of 
  four 
  distinct 
  

   pleural 
  branchihyals. 
  In 
  this 
  it 
  agrees 
  with 
  Ampliiuma, 
  as 
  it 
  does 
  also 
  with 
  Pro 
  o- 
  

   nopsis, 
  in 
  the 
  three 
  haemal 
  branchihyals.* 
  Siren 
  has 
  only 
  two 
  of 
  these 
  elements, 
  the 
  

   first 
  and 
  second 
  without 
  the 
  third. 
  As 
  a 
  consequence 
  in 
  Siren 
  the 
  third 
  and 
  fourth 
  

   pleural 
  elements 
  have 
  no 
  corresponding 
  haema.l 
  support, 
  ail 
  arrangement 
  totally 
  different 
  

   from 
  that 
  of 
  Cocytinus. 
  The 
  arrangement 
  in 
  larval 
  Amblystoma 
  and 
  Triton 
  is 
  quite 
  

   similar 
  to 
  that 
  in 
  Siren, 
  excepting 
  that 
  in 
  Triton, 
  the 
  small 
  basihyals 
  are 
  present. 
  

  

  The 
  question 
  as 
  to 
  whether 
  this 
  genus 
  was 
  in 
  life 
  branchiferous 
  or 
  not, 
  is 
  not 
  

   easily 
  decided, 
  since 
  the 
  hyoid 
  apparatus 
  is 
  about 
  equally 
  developed 
  in 
  the 
  branchi- 
  

   ferous 
  genera 
  Siren 
  and 
  Necturus, 
  and 
  the 
  air 
  breathers 
  Ampliiuma 
  and 
  Protonopsis. 
  

   Some 
  considerations 
  however 
  point 
  to 
  an 
  air 
  breathing 
  type, 
  like 
  the 
  last 
  two, 
  though 
  

   the 
  individual 
  may 
  possibly 
  have 
  been 
  immature. 
  In 
  the 
  gill-bearing 
  genera, 
  as 
  well 
  

   as 
  in 
  the 
  larvae 
  of 
  Amblystomce, 
  Tritons, 
  etc., 
  the 
  branchial 
  arches 
  approach 
  nearest 
  

   to 
  archetypical 
  perfection. 
  Thus 
  in 
  the 
  Siren 
  lacertina, 
  two 
  of 
  the 
  four 
  superior 
  

   branchihals 
  are 
  supported 
  by 
  corresponding 
  inferior 
  or 
  haemal 
  branchihyals, 
  and 
  these 
  

   in 
  turn 
  are 
  articulated 
  each 
  to 
  its 
  proper 
  axial 
  hyal. 
  The 
  absent 
  elements 
  are 
  the 
  two 
  

  

  *For 
  the 
  nomenclature 
  of 
  these 
  bones, 
  I 
  follow 
  Fischer's 
  Ueber 
  die 
  Perenuibrancbi; 
  ten 
  und 
  Derotremen 
  : 
  

   Hamburg, 
  1804. 
  

  

  