﻿AND 
  AYES 
  OF 
  NORTH 
  AMERICA. 
  

  

  241 
  

  

  The 
  oldest 
  of 
  these 
  have 
  been 
  found 
  by 
  Messrs. 
  Lea, 
  Rogers 
  and 
  Leidy, 
  near 
  to 
  Pottsville, 
  Schuylkill 
  Co., 
  Penna. 
  

   The 
  first 
  named 
  naturalist 
  referred 
  them 
  to 
  "a 
  four-footed, 
  air-breathing 
  animal, 
  allied 
  to 
  the 
  Saurians," 
  under 
  the 
  

   name 
  of 
  Sauropus 
  primaevus. 
  At 
  that 
  time 
  the 
  important 
  differences 
  between 
  the 
  Reptilia 
  and 
  Batrachia 
  were 
  not 
  

   known; 
  had 
  they 
  been, 
  disputes 
  as 
  to 
  the 
  Reptilian 
  or 
  other 
  affinities 
  of 
  these 
  creatures 
  would 
  have 
  been 
  unnecessary. 
  

   As 
  no 
  remains 
  certainly 
  referable 
  to 
  Reptiles 
  have 
  been 
  found 
  below 
  the 
  Permian 
  rocks, 
  it 
  is 
  not 
  reasonable 
  to 
  suppose 
  

   that 
  the 
  tracks 
  are 
  Reptilian, 
  as 
  Agassiz 
  has 
  insisted. 
  On 
  the 
  other 
  hand, 
  there 
  can 
  be 
  no 
  doubt 
  that 
  these 
  creatures 
  

   were 
  air-breathers, 
  as 
  Lea 
  has 
  pointed 
  out. 
  To 
  palaeontologists 
  of 
  the 
  present 
  time, 
  there 
  can 
  be 
  no 
  doubt 
  that 
  the 
  

   Sauropus 
  was 
  a 
  large 
  Batrachian; 
  which 
  position 
  is 
  entirely 
  confirmed 
  by 
  the 
  form 
  of 
  the 
  tracks 
  themselves. 
  

  

  The 
  tracks 
  which 
  come 
  next 
  in 
  order, 
  are 
  from 
  2031 
  feet 
  higher, 
  and 
  were 
  discovered 
  by 
  Wm. 
  M. 
  Gabb, 
  on 
  the 
  

   valley 
  of 
  the 
  Little 
  Schuylkill 
  River, 
  about 
  | 
  mile 
  from 
  the 
  town 
  of 
  Tamaqua, 
  Schuylkill 
  Co., 
  Penna. 
  They 
  are 
  of 
  

   peculiar 
  form, 
  and 
  much 
  more 
  like 
  those 
  of 
  the 
  Reptiles 
  than 
  either 
  of 
  the 
  others 
  here 
  mentioned. 
  

  

  They 
  are 
  on 
  the 
  surface 
  of 
  a 
  thin 
  irregular 
  shale 
  about 
  sixteen 
  inches 
  in 
  length. 
  There 
  are 
  many 
  impressions 
  on 
  

   this 
  surface, 
  one 
  of 
  the 
  most 
  abundant 
  of 
  which 
  consists 
  of 
  three 
  or 
  four 
  parallel 
  grooves. 
  Most 
  of 
  the 
  others 
  are 
  in- 
  

   termediate. 
  The 
  prominent 
  impression 
  is 
  that 
  of 
  the 
  hind 
  foot 
  of 
  an 
  animal 
  of 
  medium 
  size. 
  There 
  are 
  five 
  toes 
  of 
  

   remarkably 
  slender 
  form, 
  a 
  sole 
  broader 
  than 
  long, 
  and 
  a 
  narrow 
  and 
  rather 
  long 
  tarsus 
  projecting 
  behind. 
  The 
  

   lengths 
  of 
  the 
  toes 
  are, 
  commencing 
  with 
  the 
  shortest, 
  1—2—5—3 
  — 
  4, 
  but 
  the 
  extremity 
  of 
  the 
  second 
  extends 
  a 
  little 
  

   further 
  than 
  that 
  of 
  the 
  fifth. 
  There 
  is 
  no 
  impression 
  certainly 
  referable 
  to 
  claws, 
  though 
  there 
  is 
  a 
  weak 
  impression 
  

   at 
  the 
  ends 
  of 
  the 
  first 
  and 
  second 
  digits. 
  There 
  has 
  evidently 
  been 
  no 
  palmar 
  membrane. 
  The 
  sole 
  of 
  the 
  metatarsus 
  

   is 
  transverse, 
  and 
  is 
  separted 
  by 
  a 
  ridge 
  (in 
  the 
  impression; 
  a 
  groove 
  in 
  the 
  foot,) 
  from 
  the 
  tarsal 
  track, 
  showing 
  that 
  

   the 
  animal 
  may 
  have 
  been 
  usually 
  not 
  plantigrade, 
  but 
  rather 
  as 
  in 
  existing 
  Salamanders. 
  The 
  heel 
  is 
  about 
  as 
  long 
  

   as 
  the 
  width 
  of 
  the 
  metacarpus, 
  subacuminate, 
  and 
  most 
  impressed 
  and 
  contracted 
  on 
  the 
  side 
  next 
  the 
  shortest 
  toe. 
  

  

  Fig. 
  54. 
  

  

  Measurements. 
  

  

  In. 
  

  

  Lin. 
  

  

  Total 
  length, 
  

  

  2 
  

  

  4 
  

  

  Length 
  to 
  sole 
  from 
  heel, 
  

  

  

  9. 
  

  

  ' 
  ' 
  of 
  sole 
  to 
  fourth 
  toe, 
  

  

  

  5.5 
  

  

  " 
  " 
  fourth 
  toe, 
  

  

  1 
  

  

  23 
  

  

  Width 
  of 
  sole, 
  

  

  

  9 
  

  

  " 
  " 
  heel, 
  

  

  

  4 
  

  

  " 
  between 
  extremities 
  toes, 
  

  

  1 
  

  

  5 
  

  

  The 
  impression 
  of 
  the 
  corresponding 
  foot 
  has 
  been 
  obliterated 
  by 
  subse- 
  

   quent 
  marks. 
  At 
  a 
  distance 
  of 
  four 
  inches 
  behind 
  the 
  heel 
  a 
  track 
  of 
  four 
  toes 
  

   similar 
  to 
  that 
  already 
  described, 
  would 
  appear 
  to 
  pertain 
  to 
  the 
  same 
  animal; 
  

   they 
  are 
  imperfect, 
  and 
  the 
  heel 
  is 
  broken 
  off 
  with 
  the 
  rock. 
  

  

  A 
  single 
  impression 
  remains, 
  whose 
  position, 
  form 
  and 
  size 
  would 
  appear 
  

   appropriate 
  to 
  the 
  present 
  species. 
  It 
  belongs, 
  like 
  the 
  hind 
  foot, 
  to 
  the 
  right 
  

   side, 
  the 
  short 
  toes 
  being 
  on 
  the 
  inner 
  side. 
  Its 
  position 
  is 
  a 
  little 
  (8 
  lines) 
  be- 
  

   hind 
  the 
  posterior 
  track, 
  on 
  the 
  inner 
  side, 
  and 
  2 
  in. 
  2.5 
  lines 
  in 
  advance 
  of 
  the 
  

   imperfect 
  track 
  mentioned. 
  It 
  consists 
  of 
  the 
  impressions 
  of 
  four 
  toes, 
  whose 
  

   extremities 
  project 
  in 
  the 
  following 
  order: 
  4 
  — 
  1 
  — 
  2 
  — 
  3. 
  Within 
  the 
  inner 
  (first) 
  

   toe, 
  there 
  is 
  a 
  short 
  pit, 
  which 
  may 
  be 
  a 
  rudimental 
  5th 
  toe, 
  and 
  just 
  behind 
  it, 
  

   an 
  oval 
  depression 
  of 
  the 
  carpus. 
  As 
  in 
  the 
  hind 
  foot, 
  the 
  digits 
  are 
  remarkably 
  

   slender. 
  

  

  Lines. 
  

   Length 
  of 
  track, 
  9. 
  5 
  

  

  Expanse 
  of 
  toes, 
  5.5. 
  

  

  Some 
  of 
  the 
  trisulcate 
  impressions 
  are 
  in 
  the 
  line 
  of 
  progress 
  of 
  the 
  animal, 
  - 
  — 
  zj 
  

  

  and 
  may 
  have 
  been 
  produced 
  by 
  its 
  tail. 
  

  

  The 
  broad 
  metatarsus 
  of 
  this 
  animal 
  is 
  Batrachian, 
  as 
  is 
  the 
  apparent 
  lack 
  of 
  claws, 
  while 
  the 
  remarkably 
  slender 
  

   digits 
  constitute 
  a 
  Lacertian 
  feature. 
  The 
  most 
  singular 
  character, 
  the 
  prolonged, 
  narrow 
  tarsus, 
  is 
  not 
  found 
  in 
  any 
  

   AMEKI. 
  PlIU,OSO. 
  SCC. 
  — 
  VOL. 
  XIV. 
  — 
  Gl 
  

  

  