﻿AND 
  AYES 
  OF 
  NORTH 
  AMERICA. 
  169 
  

  

  PTEROSAIRIA: 
  

  

  EHABDOPELIX, 
  Cope. 
  

  

  This 
  genus 
  and 
  species 
  are 
  based 
  upon 
  numerous 
  bones, 
  mostly 
  scattered, 
  occurring 
  in 
  

   a 
  bed 
  of 
  very 
  hard 
  indurated 
  siliceous 
  clay, 
  of 
  a 
  dark 
  gray 
  color, 
  which 
  intervenes 
  between 
  

   the 
  usual 
  redder 
  strata 
  in 
  the 
  Triassic 
  or 
  Jurassic 
  sand-stone 
  of 
  the 
  Atlantic 
  slope, 
  at 
  

   Gwynnedd, 
  Montgomery 
  County, 
  Pa. 
  In 
  the 
  red 
  slaty 
  layers 
  occur 
  impressions 
  of 
  narrow 
  

   leaves, 
  worm 
  tracks 
  and 
  borings, 
  scales 
  of 
  Ganoid 
  Fishes, 
  and 
  rain-drop 
  and 
  ripple-marks. 
  

  

  The 
  bones, 
  which 
  are 
  very 
  abundant, 
  are 
  indicated 
  by 
  thin 
  black 
  mineral 
  layers 
  which 
  

   do 
  not 
  effervesce 
  in 
  acid, 
  and 
  whose 
  coloring 
  matter, 
  perhaps 
  a 
  phosphate 
  of 
  iron, 
  with 
  

   some 
  carbonaceous 
  matter, 
  becomes 
  blue 
  on 
  exposure 
  to 
  the 
  weather, 
  and 
  is 
  finally 
  alto- 
  

   gether 
  dissolved 
  or 
  weathered 
  away. 
  In 
  the 
  cavities 
  of 
  many 
  of 
  the 
  long 
  bones 
  may 
  be 
  

   observed 
  a 
  deposit 
  of 
  carbonate 
  of 
  lime. 
  All 
  appear 
  to 
  have 
  been 
  more 
  or 
  less 
  flattened, 
  

   and 
  their 
  walls 
  are 
  much 
  attenuated. 
  This, 
  with 
  the 
  hardness 
  of 
  the 
  matrix, 
  has 
  ren- 
  

   dered 
  their 
  preservation 
  difficult, 
  and 
  their 
  identification 
  requires 
  much 
  care 
  ; 
  and 
  though 
  

   I 
  have 
  had 
  them 
  under 
  careful 
  observation, 
  in 
  the 
  Museum 
  of 
  the 
  Academy 
  for 
  three 
  years, 
  

   I 
  am 
  hardly 
  satisfied 
  as 
  to 
  their 
  affinities. 
  It 
  would 
  appear 
  as 
  though 
  quite 
  a 
  number 
  of 
  

   individuals 
  had 
  mingled 
  their 
  remains 
  in 
  the 
  accumulation, 
  and 
  perhaps 
  more 
  than 
  

   one 
  species. 
  

  

  The 
  specimens 
  were 
  discovered 
  by 
  the 
  late 
  President 
  of 
  the 
  Academy, 
  Dr. 
  Isaac 
  Lea, 
  

   who 
  found 
  considerable 
  masses 
  of 
  the 
  rock 
  containing 
  them, 
  showing 
  an 
  accumulation 
  

   which 
  has 
  occupied 
  some 
  time 
  in 
  formation. 
  

  

  There 
  are 
  sufficient 
  reasons 
  why 
  these 
  bones 
  cannot 
  be 
  referred 
  to 
  a 
  Lacertilian. 
  They 
  

   are, 
  first, 
  the 
  presence 
  of 
  the 
  Pterosaurian 
  confluent 
  ulna 
  and 
  radius, 
  or 
  tibia 
  and 
  fibula; 
  

   second, 
  the 
  existence 
  of 
  subspatuliform, 
  distally 
  free 
  pubic 
  elements; 
  the 
  apparently 
  com- 
  

   plete 
  pneumaticity 
  of 
  the 
  long 
  bones; 
  the 
  curvature 
  and 
  lack 
  of 
  condyles 
  of 
  most 
  of 
  the 
  

   latter. 
  

  

  The 
  centra 
  of 
  the 
  vertebrae 
  are 
  much 
  depressed 
  in 
  part 
  of 
  the 
  column, 
  thus 
  agreeing 
  

   with 
  Pterosauria 
  and 
  some 
  Lacertilia. 
  Elongate 
  cervical 
  vertebrae 
  are 
  also 
  characteristic 
  

   of 
  the 
  Pterosauria, 
  but 
  exist 
  likewise 
  in 
  the 
  genera 
  Compsognathus 
  and 
  Dolichosaurus. 
  

   The 
  centra 
  of 
  the 
  vertebrae 
  have 
  projected 
  considerably 
  beyond 
  the 
  neural 
  arch, 
  and 
  the 
  

   latter 
  has 
  supported 
  an 
  elevated 
  longitudinal 
  neural 
  spine, 
  both 
  characters 
  of 
  Pterosauria. 
  

   Where 
  the 
  hypapophysis 
  has 
  existed 
  it 
  has 
  been 
  at 
  the 
  anterior 
  extremity, 
  as 
  in 
  Crocodilia 
  

   and 
  Pterodactyles, 
  and 
  not 
  behind, 
  as 
  in 
  Iguania. 
  

  

  The 
  remains 
  do 
  not 
  pertain 
  to 
  Batrachia, 
  for 
  the 
  following 
  reasons 
  : 
  The 
  creature 
  was 
  

   of 
  an 
  elongate 
  vertebral 
  axis, 
  and 
  possessed 
  none 
  of 
  the 
  peculiar 
  elements 
  of 
  the 
  Anura 
  ; 
  

  

  AMERICA. 
  PHILO. 
  SOC. 
  — 
  VOL. 
  XIV. 
  43 
  

  

  