﻿4 
  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  Nervous 
  System. 
  Cerebral 
  hemispheres 
  larger 
  than 
  optic 
  lobes, 
  extending 
  over 
  and 
  con- 
  

   cealing 
  optic 
  thalami, 
  and 
  with 
  the 
  lateral 
  ventricles 
  on 
  their 
  outer 
  side. 
  

  

  Fornix 
  and 
  arbor 
  vitse 
  none 
  ; 
  medulla 
  oblongata 
  abruptly 
  curved 
  ; 
  olfactory 
  lobes 
  terminal 
  

   pedunculate. 
  

  

  Circulatory 
  System. 
  Heart 
  with 
  three 
  or 
  four 
  chambers. 
  

  

  Aorta 
  with 
  two 
  roots, 
  and 
  rarely 
  an 
  additional 
  bow 
  ; 
  no 
  bulbus 
  arteriosus. 
  

  

  AVES. 
  

  

  Osseous 
  structure 
  as 
  in 
  Reptilia, 
  except 
  metatarsal 
  and 
  usually 
  metacarpal 
  bones 
  are 
  con- 
  

   fluent 
  with 
  each 
  other, 
  and 
  with 
  the 
  carpal 
  and 
  second 
  series 
  of 
  tarsal 
  bones 
  ; 
  first 
  series 
  

   of 
  tarsals 
  confluent 
  with 
  tibia. 
  

  

  Pubis 
  turned 
  backwards 
  and 
  more 
  or 
  less 
  confluent 
  with 
  ischium. 
  

  

  Nervous 
  System. 
  Cerebral 
  hemispheres 
  larger 
  than 
  optic 
  lobes, 
  and 
  concealing 
  optic 
  

   thalami 
  with 
  the 
  lateral 
  ventricle. 
  

  

  Fornix 
  and 
  arbor 
  vitee 
  present 
  ; 
  medulla 
  oblongata 
  bent; 
  olfactory 
  lobes 
  inferior 
  sessile. 
  

  

  Circulatory 
  System. 
  Heart 
  with 
  four 
  chambers. 
  

  

  Aorta 
  ivith 
  one 
  root 
  turning 
  to 
  the 
  right, 
  no 
  botes, 
  and 
  no 
  bulbus 
  arteriosus. 
  

  

  Class 
  I.-B-A-TiR^CHI 
  A.. 
  

  

  The 
  vomer 
  is 
  double, 
  and 
  usually 
  bears 
  teeth 
  in 
  this 
  class; 
  the 
  premaxillary 
  is 
  single 
  

   or 
  double* 
  Teeth 
  never 
  planted 
  in 
  deep 
  alveoli. 
  

   There 
  are 
  six 
  orders, 
  as 
  follows: 
  

  

  TRACHYSTOMATA. 
  

  

  Caudal 
  vertebra? 
  and 
  frontal 
  bones 
  distinct. 
  Inferior 
  pelvic 
  elements 
  not 
  confluent. 
  

   O. 
  o. 
  maxillaria, 
  prefrontalia, 
  palatina 
  and 
  pterygoidea 
  wanting; 
  nasalia 
  present. 
  

   Ethmoid, 
  two 
  lateral 
  pieces, 
  each 
  forming 
  part 
  of 
  palate. 
  

  

  Mandible 
  toothless, 
  condyloid, 
  teeth 
  pleurodont. 
  No 
  "postorbital 
  and 
  supertemporal 
  

   bones." 
  First 
  pair 
  ceratohyals 
  distinct. 
  

  

  * 
  Two 
  premaxillary 
  bones 
  are 
  usually 
  ascribed 
  to 
  the 
  Batrachia, 
  but 
  in 
  many 
  Salamanders 
  they 
  are 
  confluent. 
  

   Thus 
  while 
  they 
  are 
  double 
  in 
  Salamandra, 
  they 
  are 
  single 
  in 
  Hemisalamandra, 
  Triton 
  and 
  Diemyctylus. 
  In 
  

   Amblystomidac 
  they 
  are 
  double. 
  Among 
  Plethodontidae, 
  they 
  vary. 
  Of 
  Plethodontine 
  genera 
  Batrachoseps 
  and 
  

   Stereochila 
  (Cope 
  gen. 
  nov. 
  for 
  Pseudotriton 
  marginatus 
  Hallow) 
  have 
  them 
  single, 
  and 
  Plethodon 
  double. 
  Of 
  

   Spelerpine 
  forms, 
  Manculus 
  (Cope 
  gen. 
  nov. 
  for 
  Salamandra 
  quadridigitata 
  Holbr.) 
  Oedipus 
  and 
  Spelerpes 
  have 
  but 
  

   one, 
  and 
  Geotriton 
  and 
  Gyrinophilus 
  (Cope 
  gen. 
  nov. 
  for 
  Salamandra 
  salmonea 
  Storer 
  Pseudotriton 
  salmoneus 
  Bd.) 
  

   have 
  two 
  premaxillaries. 
  Desmognathus 
  and 
  Amphiuma 
  have 
  single 
  premaxillaries. 
  

  

  