TEXT-BOOK  OF  PALAEONTOLOGY 


TEXT-BOOK 


OF 


PALAEONTOLOGY 


BY 


KARL  A.  VON  ZITTEL 

PROFESSOR  OF  GEOLOGY  AND  PALAEONTOLOGY  IN  THE  UNIVERSITY  OF  MUNICH 


TRANSLATKD  AiND  EDITED  BY 

CHAELES  K.  EASTMAN,  Ph.D. 

IX  CHARGE  OF  VERTEBRATE  PALAEONTOLOGY  IN  THE  MUSEUM  OF  COMPARATIVE  ZOOLOOY 
AT  HARVARD  COLLEGE,  CAMBRIDGE.  MASS. 


ENGLISH  EDITION  REVISED  AND  ENLARGED  BY  THE  AUTHOR  AND  EDITOR 

IN  COLLABORATION  WITH  THE  FOLLOWING  SPECIALISTS  : 

FISHES,  A.  S.  WOODWARD  ;    AMPHIBTA,  E.  C.  GASE  ;    REPTILIA,  J.  B.  HATCHER. 

H.  F.  OSBORN,  S.  W.  WILLISTON  ;    AVES,  F.  A.  LUCAS 


VOL.   II.     WITH  373  WOODCUTS 


iLontiou 
MACMILLAN   AND   CO.,   Limited 

NEW  YORK:  THE  MACMILLAN  COMPANY 

1902 


All  right.<  reservrd 


EDITOK'S  PREFACE 


The  present  volume  continues  the  translation  of  Professor  Von  Zittel's 
Grundzüge  der  Palaeontologie  through  the  Vertebrates  as  far  as  the  class  Aves, 
and  corresponds  in  scope,  though  not  in  extent,  to  the  third  vokime  of  the 
well-known  ffaiidbuch  by  the  same  author.  The  final  volume,  when  published, 
will  be  devoted  exclusively  to  the  Mammalia. 

The  translation  of  the  Vertebrates  has  been  conducted  on  the  same  plan  as 
the  preceding  volume,  and,  like  it,  has  been  appreciably  enlarged.  Although 
nearly  all  portions  have  received  the  benefit  of  expert  revision,  and  some  are  of 
composite  authorship,  yet  on  the  whole  the  original  text  has  been  more  closely 
adhered  to  than  in  the  case  of  the  Invertebrates.  The  Classification,  also, 
departs  from  that  of  the  Grundzüge  in  only  a  few  minor  particulars.  The 
chapters  on  Fishes  and  Amphibians  are  chiefly  in  the  nature  of  a  literal 
translation  ;  those  on  Reptiles  and  Birds  are  more  modified,  at  least  in  certain 
parts. 

Dr.  AirnruR  Smith  Woodward,  of  the  British  Museum,  is  to  be  credited 
with  the  entire  translation  and  revision  of  the  class  Pisces,  on  which  group  he 
is  acknowledged  to  be  the  most  eminent  living  authority.  He  has  been 
careful,  however,  to  subordinate  his  views  on  various  taxonomic  points  to  those 
of  the  Author.  In  the  same  way  Dr.  E.  C.  Gase,  of  the  State  Normal  School 
at  Milwaukee,  Wisconsin,  performed  the  principal  labour  of  translating  and 
revising  the  chapter  on  Jmphibia,  and  assisted  in  the  task  of  rendering  the  text 
on  Beptilia  into  English.  Owing  to  the  untimely  loss  of  the  late  Dr.  George 
Baur,  of  Ghicago  University,  the  text  for  the  various  Orders  of  Beptilia  failed 
to  receive  the  benefit  of  his  coUaboration.  It  is  also  to  be  deplored  that 
the  arrangements  made  with  Professor  0.  C.  Marsh  for  the  revision  of  the 
Dinosauria  were  cut  short  by  the  final  passing  in  1898  of  this  distinguished 
patron  of  Palaeontology. 


vi  TEXT -BOOK  OF  PALAEONTOLOGY 

Grateful  acknowledgments  are  due  to  Professor  H.  F.  Osborn  and  Dr. 
0.  P.  Hay,  of  the  American  Museum  of  Natural  History  in  New  York,  and  to 
Mr.  J.  B.  Hatcher,  of  the  Carnegie  Museum  at  Pittsburgh,  for  valuable  notes 
and  suggestions  on  the  group  of  Reptiles,  especially  the  order  Dinosauria  ;  and 
to  Professor  S.  W.  Williston,  of  the  State  University  of  Kansas,  for  his  revision 
of  the  Reptilian  Orders  Squamata  and  Fferosauria,  with  notes  on  the  Plesiosauria 
and  Chelonia.  To  Mr.  Frederic  A.  Lucas,  of  the  United  States  National 
Museum  at  Washington,  was  confided  the  task  of  arranging  the  text  for  the 
class  Aves  in  its  present  shape,  which  involved  the  rewriting  of  the  entire 
systematic  and  most  of  the  general  or  introductory  part.  The  balance  of  the 
present  volume,  in  so  far  as  it  departs  from  the  original  text,  owes  its  condition 
conjointly  to  the  work  of  the  Author  and  Editor. 

In  spite  of  the  imperfections  inevitable  to  a  treatise  produced  in  this 
manner,  the  hope  is  expressed  that  the  subject-matter  will  be  found  more 
nearly  up  to  date,  and  on  the  whole  better  adapted  to  the  needs  of  English- 
speaking  students  than  would  have  been  the  case  had  the  Editor  contented 
himself  with  bringing  out  a  strictly  literal  translation.  He  would  likewise 
speak  a  word  of  gi-atitude  for  the  many  favours  and  indulgences  he  has 
received  at  the  hands  of  his  friend  and  master,  the  Author. 


CHARLES  R.  EASTMAN. 


Harvard  University, 

Juhi  1902. 


CONTENTS 


CLASS  I.  PISCES    . 

Sub-Class  1.  Selachii     . 

Order   1.   Pleuropterygii 
,,       2.  acanthodii 
„       3.  ichthyotomi 
„       4.   Plagiostomi 
„       5.  holocephali 

Sub-Class  2.  Ostracodermi 

Ordkk   1.   Heterostraci 
„        '2.   An  ASPIDA 
,,       3.  aspidocephali 
„       4.  Antiarcha 

Sub-Class  3.  Arthrodira 
Sub-Class  4.  Dipnoi 

Order  1.   Ctenodipterixi 
„        2.   Sirenoidei 

Sub-Class  5.  Ganoidei   . 

Order   1.   Crossopteryuii 
„        2.  Chondrostei 
„       3.   Heterocerci 
„       4.   Lepidostei 
„        5.  Amioidei 

Sub-Class  6.  Teleostei  . 

Order   1.   Physostomi 
„       2.   Physoclysti 

CLASS  II.  AMPHIBIA 

Order  1.  Stegocephalia 
„   2.  Gymnophiona 
,,   3.  Urodela 
„   4.  Anüra  . 


PAQE 

2 

17 
19 
20 
22 
25 
44 

50 
50 
53 
54 
56 

58 

61 
61 

64 

65 
69 
73 

75 
79 

89 

92 
93 

101 

114 

117 
135 
135 
137 


TEXT -BOOK  OF  PALAEONTOLOGY 


CLASS  III.  REPTILIA 

Order  1.  Rhynchocephalia 

„  2.  Squamata 

„  3.  ichthyosauria 

„  4.  Sauropterygia 

„  5.  Theromorpha 

„  6.   Chelonia 

„  7.  Crocodilia 

„  8.    DiNOSAURIA 

,j       9.  Pterosauria 

CLASS  rv.  AVES  . 

Sub-Class  1.  Saururae  . 

Order  1.  Archaeornithes 

Sub-Class  2.  Ornithurae 

Super-Order  1.  Odontolcae 

Super-Order  2.  Odontormae 

Super-Order  3.  Dromaeognathae 
Order  1.  Struthiones 
„       2.  Apteryges 
„       3.  Cryptüri 


Super-Order  4.  Euornithes 

Order  1. 

Impennes 

„        2. 

Cecomorphae 

,        3. 

Grallae 

4. 

Chenomorphae 

,        5. 

Herodii 

6. 

Steganopodes 

,        7. 

Opisthocomi 

»        8. 

Gallinae 

,        9. 

Oolumbae 

,      10. 

ACCIPITRES 

,      11. 

PSITTACI 

,      12. 

PiCARIAE 

,      13. 

Passeres 

INDEX 


Phylum  VIII.    VERTEBRATA 

^  Bilatemlly  symmetrical  animals,  with  a  cartilaginous  or  ossified  vertebral  axis, 
which  is  usually  composed  of  a  series  of  similar  segments,  the  same  suppmiing  the 
central  nervous  System  and  dividing  the  trunk  into  a  dorsal  and  a  ventral  portion. 
Never  more  than  two  pairs  of  limbs. 

The  vertebral  column  develops  from  a  rod-like  cellular  tissue  of  gelatinous 
consistency  (chorda  dorsalis),  of  which  the  outer  (skeletogenous)  layer  gradually 
subdivides  into  a  number  of  similar  segments,  which  are  originally  cartilagin- 
ous but  subsequently  calcified  by  the  deposition  of  phosphate  of  lime  or  are 
replaced  by  bone  substance.  At  the  anterior  end  of  the  vertebral  column  is 
the  cranial  capsule  enclosing  the  brain,  also  the  visceral  skeleton.  The 
appendicular  skeleton  is  likewise  preformed  in  cartilage,  and  among  the  higher 
Vertebrata  usually  develops  completely  into  bone  substance.  Only  some  of 
the  lowest  Vertebrata  exhibit  a  persistently  cartilaginous  internal  skeleton. 
The  calcification  of  the  cartilage  in  the  sharks  and  skates  takes  place  in  such 
a  way  that  a  homogeneous  limey  substance  is  deposited  between  the  cartilage 
cells,  while  in  ossification  the  original  cartilage  cells  disappear,  and  by  re- 
sorption  of  the  intercellular  substance  there  arise  canals  with  blood  vessels 
(Haversian  canals)  as  well  as  small  hollow  spaces  (lacunae,  bone  corpuscles) 
filled  with  bone  cells  (osteoblasts).  The  latter  are  connected  with  the 
Haversian  canals  by  very  fine  tubules  (primitivröhrchen)  radiating  in  all 
directions.  In  many  fishes  the  lacunae  (bone  corpuscles)  are  wanting,  so  that 
the  primitive  tubules  arise  directly  from  the  Haversian  canals. 

The  skeleton  of  the  extremities  consists  of  several  articulated  segments 
which  exhibit  an  extraordinarily  varied  arrangement  according  to  the  function 
of  the  limbs. 

The  nervous  system  consists  of  a  central  organ  divided  into  brain  and 
spinal  chord,  from  which  numerous  nerves  arise  and  extend  throughout  the 
whole  of  the  body.  The  blood  is  first  driven  to  the  organs  of  respiration 
(gills  or  lungs)  by  means  of  a  heart  provided  with  one  or  two  auricles,  and 
after  it  has  traversed  the  body  in  numerous  veins  it  returns  to  the  heart. 
The  Oesophagus,  stomach,  intestine,  liver,  kidneys,  and  spieen,  as  well  as  the 
Organs  of  generation,  lie  in  the  ventral  part  of  the  body.  The  skin  is  often 
provided  with  hairs,  spines,  scales,  feathers,  or  bony  plates. 

As  a  rule  only  remains  of  the  bony  skeleton,  teeth,  or  hard  ossified  parts 
of  the  skin  are  available  to  the  palaeontologist  for  investigation ;  but  these 
can  generally  be  determined  with  great  certainty. 

The    following    five    classes    of    Vertebrates    are    distinguished :  —  Pisces, 

VOL.  II  B 


VERTEBRATA 


PHYLUM  VIII 


Amphibia,  lieptilia,  Aves,  and  Mammalia.  Recently  the  immerous  groups  of 
Tunicata  and  Leptocardii  have  been  placed  with  these  as  special  classes  and 
often  regarded  as  the  ancestors  of  the  Vertebrates.  As  these  have  left  no 
fossil  remains  in  the  rocks,  the  paUieontologist  discovers  no  clue  to  the  origin 
of  the  Vertehrata. 

OlaSS    1.      PISOES.      Fishes. 


Fig.  1. 

A,  Scale  of  Scyllium  canicula. 
Recent.  si/j.  B,  Scales  ot  Carcharias 
(l'rionodon)  gangetieus.  Recent. 
Magnitied.     , 


Nat.  size. 


Cold-hlooded  animals  living  in  water  and  usually  hreathing  exdusively  hy  gills. 
Limbs  in  the  form  of  fins.  Skin  with  scales  or  bony  plates,  rarely  naked.  Vertebral 
axis  ending  in  a  vertical  caudal  fin.  Heart  with  a  Single  ventride  and  auride.  No 
amnion  or  allantois. 

To  the  skin  striictures  of  fishes  belong  the  scales,  dermal  bones,  spines, 

fin  rays,  and  teeth. 

Scales. — Louis  Agassiz  distinguished  four  kinds  of  scales,  to  which  in  his 

System  there  correspond  as  many  Orders. 

1.   Placoid  scales  occur   only   among  the   Selachians.       They   are   usually 
^  j.  small  rhombic  plates,  star- 

shaped,  leaf-shaped, 
pointed,  spade-shaped,  or 
even  conical  structures 
which  lie  close  together 
and  form  a  rough  mosaic 
(shagreen).  The  placoid 
*'^''-  -•  scales  are  often  of  variable 

„»ÄSEpi„r'pifocer'  form  on  different  parts  of 
the  body,  and  sometimes 
(e.g.  among  the  rays)  single 

tubules  are  conspicuous  by  their  large  size  and  sculpture,  and  appear  as  thick 

plates   externally  roughened 

or  provided  with  spines. 

Placoid    scales    (Figs.     1-3) 

have   the  structure  of   teeth 

and  consist  of  a  basal  plate 

(of  thick  phosphate  of  lime) 

penetrated     by     vertical 

bundles  of  connective  tissue 

fibres  sunk  in  the  skin,  and 

a    freely     projecting     upper 

part    composed    of    dentine 

and    penetrated    by    coarser 

and  finer  little  canals.     All 

the  canals  arise  from  a  cavity 

/T-.nlT^r.     /.i\   fill    r1         '  i^U  -ß.  Basal  plate.     D,  Dentine.     S,  Enarael ;  c,  Cutis;  d,  Horizontal 

^^puipa,  p)  niiea  Wltn  COnneC-  dentine  canals  ; /,  Bundles  of  connective  tissue;  h,  Large  principal 
tive     tissue     and     tooth     cells    f^flf^'o   HertxS*^"''"'^'  «pwar.ls  ;  o,  Odontoblasts  ;  /',  rnlp  cavity 

(odontoblasts,    o),    and    sub- 

divided  outwards  into  continually  finer  branches.  Besides  phosphate  of  lime 
the  dentine  comprises  small  quantities  of  fluoride  and  carbonate  of  lime.  The 
core  of  dentine  is  covered  by  a  thiii,  shining,  very  hard  structureless  outer 
layer,   which  corresponds   histologically  and   chemically  with  the  enamel   of 


Sagittal  section  through  a  scale  oi  Scymuus  lichia.    Ilecent.     *>i)^i. 


PISCES 


teeth.     Placoid  scales  ofteii  fall  out  and  are  replaced  like  teeth  by  successional 
tubercles. 

2.  Ganoid  scales  (Figs.  4-7)  attain  a  larger  size  than  placoid,  and  usually 
Cover  the  whole  trunk.  They  are  of  rhombic  or  rounded  shape,  and  in  the 
latter  case  overlap  one  another 

like    roofing    tiles.      Those    of  ^  ^' 

rhombic  form  are  usually 
arranged  in  regulär  rows,  and 
are  movably  articulated  by  a 
tootli-like  process  of  the  upper 
margin  which  fits  into  a  corre- 
sponding  hollow  on  the  inner 
side  of  the  adjoining  scale. 
The  exposed  outer  face  is 
covered  by  an  enamel  layer 
(ganoine) ;  it  is  usually  thick 
and  shining,  sometimes  dark- 
coloured,  smooth,  rugose,  or 
ridged,  and  beneath  it  there  is  a  basal  plate  consisting  of  bone  substance  and 
pierced  by  numerous  canals.  Among  the  Palaeozoic  genera,  indeed,  the  basal 
plate  shows  great  complexity.     The  deeper  lavers  include  numerous  lacunae 


'^^ 


!^  Scale  of  Cosmoptychins  sfrlutna,  Aji'. 
sp.  Outer  (A)  and  inner  (B)  aspects. 
Lower  Carboniferons.     '■^/i. 


Two  scales  of  Poly- 
pterus  bichir,  Bonap, 
Recent.  Inner  aspect. 
Nat.  size. 


Fio.  G. 

Vertical  section  of  a  scale  of  Leptdosteiix 
Kecent.  .S',  Enamel;  d,  Dentine  tubules 
h,  Haversian  canal.    »oo/^  (after  O,  Hertwig). 


Vir..  7. 

Vertical  section  of  a  scale  of  Gli/ptolepis, 
highly  niagnified.  Devonian.  «,  b,  I^yer 
of  vasodentine  with  spindle-shaped  bone 
lacunae ;  c,  Bony  layer  with  Haversian 
canals  ;  d,  Layer  with  tine,  branching 
dentine  tubules  (cosniine)  ;  e,  Enamel  (after 
Pander). 


(bone  corpuscles)  and  Haversian  canals,  while  the  upper  layers  as  a  rule  are 
traversed  only  by  fine  dentine  tubules. 

3.  Cydoid  and  ctenoid  scales  are  exactly  alike  in  general  characters,  being 
thin,  elastic,  and  of  rounded,  elliptical,  four-,  five-,  or  six-sided  shape.  They 
consist  of  a  homogeneous,  transparent  shining  surface-layer  of  phosphate  of 
lime,  and  of  a  base  of  connective  tissue  deficient  in  alkalies.     The  scales  are 


VERTEBRATA 


l'HYLUM  YIII 


C 


\ 


developed  in  special  folds  of  the  cutis,  and  generally  overlap  one  another  like 

roofing  tiles.  Cycloid  scales 
(Fig.  8,  A-C)  generally  exhibit 
a  rounded  or  oval  form  and  a 
simple  non  -  serrated  hinder 
l)order.  In  ctenoid  scales 
Fig.  8,  D,  E)  there  project 
irom  the  hinder  border  small 
points  and  denticles,  which  are 
sometimes  arranged  in  several 
series  one  behind  the  other, 
and  may  indeed  cover  a  con- 
siderable  part  of  the  hinder 
surface  and  have  the  same 
rttructure  as  the  superficial 
layer.  From  the  so  -  called 
primitive  field  divergent  lines 
radiate  chiefly  forwards  and 
backwards,  and  sometimes  also 
pass  into  reticulations ;  these 
lines  being  merely  fissure-like 
interruptions  in  the  outer  layer 
(Fig.  9).  Between  the  upper 
parallel  layers  of  the  fibrous 
connective  tissue  of  the  base 
there    are    often    intercalated 

small,    round,    concentrically    marked    calcareous    bodies,    which    are    most 

numerous  beneath  the  primitive  field,  sometimes  fused  vvith  each  other  into 

a  continuous  layer,  and  here  and  there 

exhibit  bone  cells.     Such  scales  are  not 

essentially    different    from    very    thin 

ganoid  scales. 

The  large  plates,  shields,  spines,  etc., 

which  partly  cover  the  body  and  pärtly 

the    head    of    many    fishes    {Arthrodira, 

Siluridae,    Acipenseridae),    consist    either 

of  uniform  bone  substance,  or,  like  the 

ganoid    scales,    of    layers    of    ostaine, 

dentine,  and  enamel. 

Large      spines      (Ichthyodorulites), 

(Fig.  10)  generally  occur  on  the  front 

margin  of  the  median,  and  more  rarely 

of  paired  fins,  or  on  the  head  of  carti- 

laginous    fishes    (Selachii).       They    are 

muscles  by  an  elongated  base,  only  exceptionally  (Chimaera)  articulated  with 

a  lower   piece.     Like   the   scales   and   teeth   of    Placoid   fishes   they    consist 

either  entirely  of  dentine  or  of  dentine  and  vasodentine.     Ichthyodorulites 

often  attain  a  remarkable  size,  and  occur  isolated  in  a  fossil  state,  while  the 

Palaeozoic  examples  are  sometimes  characterised  by  a  rieh  sculpturing. 

The  outer  projecting  parts  of  the  fins  are  also  to  be  regarded  as  dermal 


Fig.  S. 

Cycloid  scales  of  A,  Leiiciscns,  B,  Mormynts,  and  C,  Nmicrates. 
Ctenoid  scales  of  D,  Solea,  and  E,  Hdacanthus.     Much  magnified. 


Flu.  9. 

External  surface  of  a  scale  of  Pleuronectes,  to  sliow 
tlie  vacuities  (x)  between  the  raised  concentric  lines. 
Very  much  magnified  (after  Baudelot). 

usually    implanted    loosely    in    the 


CLASS I 


PISCES 


structures.     They  arise  as  folds  of  skin,  which  gradually  become  strengthened 

by  numerous   horny  fibres  (Selachii,  Dipnoi).      In  most  Ganoids  and  Tele- 

osteans  these  fibres  are  replaced  by  bony  rays,  which 

consist  of  two  closely  apposed  halves.     In  the  Acan- 

thopterygii  (Fig.    11)  each    half   consists  of  a   single 

piece ;    in  the  Malacopterygii  the  rays  are  subdivided 

by  transverse  sutures  into  numerous  little  pieces  and 

often  brauch  towards  the  end.     Spiny  and  articulated 

rays  frequently  occur  in  one  and  the  same  fin,  and  in 

this  case  the  spines  are  always  in  front.     The  rays  of 

the  unpaired  fins  are  borne  as  a  rule  on  flat  cartila- 

giuous  or  bony  supports  with  which  they  articulate 

(Fig.   11,  C).     These  fin  supports  penetrate  between 

the  spinous  processes  of  the  vertebrae  and  are  known 

as  axonosts  or  (according  to  their  position)  as  inter- 

neurals  and  interhaemals. 

In  many  Selachians  (Pristiophorus,  Eaja)  every 
gradation  can  be  observed  between  the  Placoid  scales 
of  the  externa!  skin  and  the  teeth ;  and  as  both 
exhibit  essentially  the  same  histological  structure, 
while  the  teeth  only  assume  a  firm  connection  with 
the  head  bones  in  the  higher  fishes,  the  teeth  must 
indeed  be  regarded  as  dermal  structures. 

Among  fishes  all  the  cartilages  or  bones  surround- 

ing  the  mouth  and   gill  cavity  may 

bear  teeth.      They  originate    in   the 

calcification    of    skin    papillae,    con- 

sisting    of    a    crown     which     freely 

projects,    and    of    a    root    which    is 

surrounded    with    connective    tissue 

or    united     with    the     head     bones. 

Their     form     and     proportions     are 

extraordinarily  variable  according  to 

their  functions.     All  gradations  exist 

from  the  minute  granulär  denticles  of 

the  perch  to  the  long  brush-like  teeth 

of  the  sheat-fish,  to  the  robust  pre- 

hensile    teeth    of    the    pike  and    the 

powerful  conical  or  laniary  teeth  of 

Dendrodus  or  Foriheus.     Among  the   UpperT 

sharks  there  often  occur  teeth  shaped 

like  an  arrow-head,   flattened  on  one  side,  with  or  without 

lateral   denticles.     To  crush  the  food   there  are  sometimes 

obtusely  conical  teeth,  sometimes  bean-shaped,  hemispherical, 

or  pavement-like  teeth,  and  in  certain  Selachii  the  teeth  are 

closely  pressed  together  into  a  continuous  mosaic.  Peculiar 
cutting  dental  plates  of  considerable  size  occur  in  Diodon,  Arthrodira,  and 
Chimaera. 

The   number   of    the   teeth   in   fishes    is   also   as   varied    as    their   shape. 
AVhile    the    Dipnoi,    Chimaeroidei,    and    Gymnodonts    possess    only    four    to      ^ 


Fio,  10. 

Dorsal  fin  spine  of  Ilybodiis. 
Aas ;  Boll,  Würteinberg. 


Fig.  11. 

.-1,  B,  Rays  from  the 
dorsal  fin  of  an  Acan- 
thopterygian.  C,  Fin 
snpport  or  interspin- 
ons  bone. 


VEKTEBRATA 


PHYLUM  VIII 


six  teeth  in  all,  in  many  Sharks  and  Teleosteans  these  are  numbered  by 
hundreds. 

In  the  young  of  almost  all  fishes  the  teeth  are  fixed  to  the  cartilaginous 
or  bony  support  by  fibrous  connective  tissue,  and  in  sharks  and  in  many  bony 
fishes  this  arrangement  persists  throughout  life,  so  that  after  long  maceration 
the  teeth  can  easily  be  stripped  oif  their  base.  In  bony  fishes  and  many 
ganoids  the  roots  of  the  teeth  become  fused  with  the  bone,  and  a  socket-like 
elevation  usually  grows  round  the  teeth.  Exceptionally,  teeth  are  also  im- 
planted  in  distinct  sockets.  The  successional  teeth  are  usually  developed  by 
the  side  of  the  functional  teeth  and  continually  push  them  out. 

With  few  exceptions  the  crown  of  the  tooth  consists  of  dentine,  vaso- 
dentine,  and  enamel,  the  root  of  vasodentine  or  osteodentine.  The  enamel 
forms  a  very  thin  brilliant  homogeneous  superficial  layer,  as  hard  as  glass,  and 


Fig.  12. 

Vertical  section  of  a  tooth  of  Lepi- 
dotiis  {Sphaerodus)  gigas,-  Ag.  Con- 
sisting  of  dentine  (D)  and  enamel  (S). 
Upper  Jurassic.     Much  niagnified. 


Fig.  13. 

Vertical  section  of  part  of  a 
tooth  of  a  pike  (Esox).  Recent. 
D,  Dentine.  .S,  Enamel.  VD, 
Vasodentine.  W,  Root  of  tooth. 
Much  magnitied  (after  Sternberg). 


Fig.  14. 

Vertical  section  of  a  tooth  of 
Otodus.  Eocene.  D,  Dentine. 
S,  Enamel.  VD,  Vasodentine. 
Much  magnifled. 


is  easily  recognised  in  polarised  light  by  its  double  refraction.  Very  fine 
unbranched  tubules  frequently  pass  from  the  dentine  into  the  enamel.  It  is 
composed  of  phosphate  of  lime,  with  a  little  fluoride  of  lime,  a  little  carbonate 
of  lime,  phosphate  of  magnesia,  and  a  very  small  quantity  of  organic  matter. 
The  dentine  or  tooth  substance  contains  no  fluoride  of  lime  but  much  more 
organic  matter  than  the  enamel,  is  less  hard,  and  dissolves  more  slowly  in 
acids.  Typical  dentine  (Fig.  12,  D)  is  traversed  by  very  fine  outwardly 
branching  tubules,  which  radiate  outwards  from  the  pulp  or  its  branches,  and 
contain  thread-like  processes  of  the  tooth  cells  (odontoblasts).  The  dentine  is 
also  very  frequently  traversed  by  large  anastomosing  canals  (Haversian  canals), 
in  which  blood-vessels  penetrate,  and  the  walls  of  which  are  covered  with 
odontoblasts.  Fine  dentine  tubules  then  radiate  in  a  peripheral  direction 
from  these  large  canals.  This  vascular  modification  of  tooth  substance  is 
known  as  vasodentine  (Figs.  13,  14,  VD). 


CLASs  I  PISCES  7 

The  root  of  the  teeth  of  fishes  is  distinguished  from  the  crown  by  the 
absence  of  an  enamel  layer.  It  consists  either  entirely  of  vasodentine,  or  also 
exhibits  bone  cells  with  radiating  primitive  tubules  (osteodentine). 

The  internal  skeleton  of  fishes  shows  that  in  the  different  Orders  of  this 
class  there  persist  until  adult  life  almost  all  the  stages  of  developmenL  which 
are  only  temporary  among  the  higher  Vertebrates.  The  whole  process  of  the 
gradual  segmentation,  chondrification,  and  ossification  of  the  vertebral  column 
and  of  the  rest  of  the  skeletqp  is  quite  clear  in  the  different  groups  of  fishes, 
and  the  fossil  forms  from  the  Palaeozoic  and  Mesozoic  deposits  furnish  the 
most  important  Information  in  this  respect. 

Vertebral  Column. — The  first  trace  of  the  internal  skeleton  in  all  Vertebrata 
is  confined  to  an  elastic  rod-like  structure  (chorda  dorsalis)  extending  longi- 
tudinally  on  the  dorsal  side  of  the  body,  consisting  of  oil-bearing  cells,  and 
enveloped  in  a  laminated  sheath.  Upon  the  chorda  dorsalis  lies  the  spinal 
chord ;  below  it,  the  ventral  cavity  of  the  body. 

The  vertebral  column  persists  throughout  life  in  this  primitive  stage  only 
in  Ämphioxus.  The  notochord,  indeed,  still  remains  unsegmented  in  the 
Cyclostomes,  but  the  spinal  chord  is  already  protected  by  arch-shaped  bars  of 
cartilage  developed  in  the  sheath  of  the  notochord  (neural  arches) ;  ajid  at  the 
front  end  there  is  developed  a  cartilaginous  capsule  for  the  reception  of  the 
brain. 

In  all  typical  fishes  the  notochord  is  divided  into  ring-shaped  segments 
(vertebrae),  and  is  partly  or  completely  cartilaginous  or  bony.  The  chondri- 
fication or  ossificatioit  always  arises  in  the  outer  skeletogenous  layer  of  the 
notochordal  sheath,  and  begins  with  the  upper  and  lower  arches. 

A  complete  vertebra  consists  of  a  vertebral  body  (centrum)  surrounding 
the  notochord,  two  upper  half-arches  surrounding  the  neural  canal  (neuro- 
pophyses),  and  two  lower  half-arches  (hemapophyses).  The  upper  arches  are 
united  with  a  dorsal  spinous  process  (processus  spinosus,  spina  dorsalis,  or 
neural  spine),  while  the  lower  arches  either  unite  in 
the  caudal  region  into  a  ventral  spinous  process  (spina  ! 

ventralis),   or    remain    as    lower    transverse    processes      «.« 
(parapophyses). 

In    many    fishes    provided    with    a    cartilaginous 
vertebral  column  (Selachians  and  Acipenseroids),  there 
are  interposed   between   the  upper  and   lower  arches 
cartilaginous    intercalary    pieces    (intercalaria)    which      ha 
sometimes  exceed  the  arches  in  size  (Fig.  15,  i).  ^^^  ^^ 

The  vertebral  centra  or  vertebral  bodies  in  cartila-  rj.^^^  camiai  vertebrae  of 
ginous   fishes   usually  Surround   a   persistent   remnant   Centrophoms  ux  side  viev/.   m, 

ö  111-1  •  1  11  TT-       Haemal  arches;  i,  Intercalary 

of     the     notOChoi'd,     which     pierces     the     whole     OI     the    cartilages ;  na,  Neural  arches ; 

vertebral   column   and    partly  fills   the    intervertebral   Hasse)!^^^  ^     ^^"^'^ 
Spaces.     The  cartilaginous,  calcified,  or  bony  anterior 

and  posterior  faces  of  the  vertebral  bodies  are  deeply  hollowed  like  double 
cones  (amphicoelous),  and  thus  give  the  centrum  an  hour-glass  shape. 
In  the  Selachii  there  is  usually  a  partial  calcification,  in  the  Ganoidei 
and  Teleostei  an  ossification  of  the  primitive  cartilaginous  centrum. 
While,  however,  the  bony  fishes  generally  exhibit  complete  ossification 
of  the  whole  vertebra  with  all  its  processes,  the  ganoids  of  the  Palaeozoic 
and    Mesozoic    deposits    display    every    possible    stage    in    the    process    of 


VERTEBRATA 


PHYLUM  VIII 


Fig.  ig. 


ossification.      In    completely   ossified    vertebrae    the    anterior    and    posterior 
edges    of    the    amphicoelous    ceutra    are    in    close    contact    and    also    bound 

together  by  ligaments  :  the  notochord 
persists  only  in  the  intervertebral 
Spaces,  and  does  not  form  a  continuous 
thread.  The  arches  are  firmly  fused 
with  the  centrnni,  and  on  the  anterior 
margin  of  the  upper  arches  there 
usually  projects  a  short  process 
(zygapophysis),  which  overlaps  a 
similar  posterior  process  of  the  centrum 
on  each  side,  and  thus  strengthens  the 
Union  of  contiguous  vertebrae  (Fig.  17). 
In  the  hinder  or  caudal  region  the  lower 
arches  form  a  ventral  spinous  process 

Vertebrae  froni  the  abdominal  region  of  the  Sturgeon    (Fig.    17);    in  the  anterior  Or  abdominal 

iAcipense72,mHide  View  (A)  and  i^^  reorion  the  lower  arches  project  as  short 

section  (B).    Cartilage  dotted,  bone  white.,    ch,  Noto-         ö  r      J 

chord;/,  Nerve foramina;  ;ia,Haemal  arches ;  i,  In ter-  parapophvses,     and     Serve     as     SUpportS 

calary  pieces ;  m,  Neural  canal ;  n,  Neural  arcjhes ;  7        ^1  ^  ^        •  1  m 

p,  Transverse  processes  (parapophyses) ;  r,  Ribs  ;  s,  lOY  the  mOVable  I'lbs.        i  rue    tranSVerse 

Hertwigf  "^^^'^^''^  =  '^''  ^^'"'^^  "P"'"'  ^''^^'■'  ^-   processes  (diapophyses,  processus  trans- 

versi),  to  which  the  ribs  are  attached  in 
the  higher  Vertebrata,  and  which  arise  from  the  upper  arches,  occur  only 
exceptionally  (Poh/pterus,  Pleuroneäes)  besides  the  parapophyses.  In  the 
Cyclostomi  and  Chimaeras  ribs  are  entirely  absent ;  in 
the  Selachii  and  cartilaginous  ganoids  they  are  usually 
feebly  developed  or  rudimentary.  The  ribs  of  the  two 
sides  are  never  united 
with  each  other  at  the 
ventral  border  either 
directly  or  through  the 
Intervention  of  a 
sternum.  The  inter- 
muscular  bones,  which 
arise  in  the  membrane 
between  the  muscle 
plates,  must  not  be 
confounded  with  ribs  ; 
they  are  delicate  bony 
filaments,  often  forked 
at  one  end,  which  are 
disposed   between   the      ^    ^,     _^  ^       ,.v   ^         .  ,.  ^.   ,  ,     •.  ^-    , 

^    -  Caudal  vertebrae  of  the  Carp.    A,  Vertical  longitudinal  section  of  three 

muscles,     and  rest    on    vertebrae.    B,  Detached  vertebra,  chiefly  in  side  view.     C,  Last  abdominal 

tVip     vprf a1       1  +           ^^^^  ^^^^  caudal  vertebra.    c,  Centrum;  ch,  Notochord;  ha,  Haemal  arches; 

tue     verieDrai  centra,     »,  Neural  arches  ;  sp.d,  Neural  spines  ;  za,  Zygapophyses  (after  K.  Hertwig). 

arches,  or  ribs, 

The  number  of  the  vertebrae  in  fishes  varies  most  remarkably  in  the 
different  groups.  In  certain  bony  fishes  (Ostracion)  only  15  are  to  be  counted, 
while  in  others  there  are  70  to  80,  in  the  eel  about  200,  in  many  sharks  from 
350  to  400. 

The  hinder  end  of  the  vertebral  column  in  the  embryonic  stage  of  all 
fishes  is  (Uph?jcerml  or  heterocercal.     In  the  first  condition  the  vertebral  column 


Fig.  17. 


PISCES 


extends  in  a  straight  line  to  the  end  of  the  trunk,  and  is  symmetrically 
fringed  above  and  below  with  the  caudal  fin.  The  Cyclostomi,  Dipnoi,  and 
many  Crossopterygii  (Fig.  18)  remain  in  this  embryonic  stage  throughout  life. 
In  the  heterocercal  fishes  (sharks,  rays,  many  ganoids)  the  end  of  the  yertebral 


Fig.  18. 

Di pliycercal  caudal  fin  ofPolyjjterus  bichir,  Bonai).   Receiit. 
eh,  Minder  eud  of  vertebral  column  (after  KöUiker). 


Externally  and  internally  heterocercal  caudal 
fin  of  the  Sturgeon  (Acipenser). 


column  is  bent  upwards,  and  completely  passes  into  the  upper  lobe  of  the 
caudal  fin,  which  is  usually  elongated,  and  exceeds  the  lower  lobe  in  size  (Fig. 
19).  Between  the  diphycercal  and  heterocercal  types  of  tail  there  are  many 
gradations.  In  the  hetero-diphycercal  tail  the  vertebral  column  is  elongated 
in  a  gentle  upward  curve  at  its  hinder  end,  and  fringed  above  and  below  with 


Fi(i.  2(1. 

Internally  lieterocercal  caudal  ttn  of  Amia. 
Recent.  ch,  Cartilaginous  hinder  end  of  the  ver- 
tebral column,  with  rudlnient  of  notochord  (after 
Kölliker). 


Fig.  21. 

Externally  hoinocercal  (stegurous)  caudal  fin  of  the 
SalniOH  (Salmo  salar).  a,  b,  c,  Upper  roofing  bones  of 
the  end  of  the  notochord  ;  ch,  Projecting  end  of  the 
notochord  (after  Kölliker). 


fin  rays ;  but  the  rays  of  the  upper  lobe  are  much  less  developed  than  those 
of  the  lower  lobe.  Sometimes  also  the  external  caudal  fin  consists  of  two 
similar  lobes,  while  the  vertebral  column  is  bent  upwards,  and  extends  far 
into  the  upper  lobe  (Fig.  20).  Such  fins  are  externally  homocercal,  internally 
heterocercal.  In  the  hemi-heterocercal  tail  the  upper  lobe  of  the  externally 
symmetrical  caudal  fin  is  still  partly  or  completely  covered  with  scales. 


10  VERTEBRATA  phylum  viii 

In  all  cycloid  and  ctenoid  fishes  the  caudal  fin  is  externally  and  internally 
homocercal  (Fig.  21).  The  vertebral  column  terminates  in  front  of  the  fin 
with  a  vertebra  bearing  a  broad,  vertical,  fan-shaped  plate  (hypural),  which  is 
formed  by  the  fusion  of  several  fin  supports  and  haemapophyses.  This 
terminal  plate  generally  encloses  a  short,  upwardly  directed  remnant  of  the 
notochord  or  a  bony  style  (urostyle).  There  is  thus  an  internal  heterocercy 
as  the  basis  of  the  homocercal  tail. 

Xearly  all  Palaeozoic  fishes  have  a  diphycercal  or  heterocercal  tail ;  hemi- 
heterocercal  forms  begin  with  Äcentropliorus  in  the  Upper  Permian,  and  are 
common  in  the  Triassic  and  Jurassic.  The  Cretaceous,  Tertiary,  and  Recent 
bony  fishes,  when  adult,  exhibit  a  homocercal  tail ;  but  in  their  immature 
condition  there  is  always  a  diphycercal  or  heterocercal  stage. 

Skull. — The  head  forms  the  anterior  end  of  the  vertebral  axis,and  its  skeleton 
exhibits  a  greater  complexity  in  fishes  than  in  the  higher  Vertebrates.     Except 

Kr    Po 


Skull  aiul  branchial  apparatus  of  Squatina  vulgaris,  Risso.  Recent.  BR,  Rays  of  the  hyoid  arch  ;  Cßr,  Cerato- 
branchial ;  Co,  Copula  of  the  hyoid  arch  ;  Co',  Hindermost  copula  of  the  branchial  arches  ;  EBr,  Epibranchial ; 
Eth,  Ethmoidäl  region  ;  Hy,  Hyoid  arch  ;  HBr,  Hyobranchial ;  HyM,  Hyomandibular  ;  L,  L',  L",  Anterior  (pre,- 
niaxillary),  posterior  (niaxillary),  and  inferior  (preniandibular)  labial  cartilages  ;  Md,  Lower  i'aw  or  mandible  ;  Occ, 
Occipital  region  ;  Po,  Postorbital  process  ;  PQ,  Palatoquadrate.     III-VII,  Branchial  arches  (after  Gegenbaur). 

in  Amphioxus,  the  brain  is  enclosed  in  a  cartilaginous  or  bony  capsule,  the  skull 
or  cranium,  which  also  contains  the  organs  of  hearing,  sight,  and  smell.  With 
the  skull  are  connected  a  large  number  of  paired  cartilaginous  or  bony  pieces, 
which  together  form  the  so-called  visceral  skeleton. 

The  embryonic  primordial  cranium  of  all  Vertebrates  is  cartilaginous,  and 
is  developed  like  the  vertebral  column  round  the  notochord,  which  always 
extends  far  into  the  base  of  the  skull. 

Among  the  Selachii  (Fig.  22)  the  whole  cranial  skeleton  is  cartilaginous, 
and  only  exceptionally  hardened  by  the  deposition  of  phosphate  of  lime 
(Ichthyotomi).  The  long  cranial  capsule  does  not  exhibit  any  sutures,  and 
comprises  in  its  anterior  part  (ethmoidäl  region)  the  olfactory  nerves,  in  the 
middle  (orbital  region)  the  optic  nerves  and  eyes,  in  the  hinder  part  the 
Organs  of  hearing  and  the  hemispheres  of  the  cerebrum  and  cerebellura.  The 
visceral  skeleton  consists  of  a  number  of  variously  shaped  cartilaginous  arches, 
of  which  the  f oremost  (palatoquadrate)  surrounds  the  cleft?  of  the  mouth,  and 
is  characterised  by  its  'relatively  large  size.     The  two  movable  branches  of 


CLASS  I 


PISCES 


11 


the  lower  jaw  are  articulated  with  the  palatoquadrate.  Two  small  labial 
cartilages,  sometimes  termed  maxilla  and  premaxilla,  occur  on  each  side  in 
front  of  and  below  the  palatoquadrate.  The  latter  element  is  connected 
with  the  skull  in  the  ethmoidal  region  by  ligament,  and  in  the  hinder  portion 
by  the  second  visceral  arch,  of  which  the  upper  portion  (hyomandibular)  is  in 
contact  with  the  auditory  region  of  the  skull,  while  the  lower  portion  forms 
the  hyoid  arch.  The  palatoquadrate  and  mandible  are  provided  with  teeth. 
Behind  the  hyoid  arch  there  follow  five  (rarely  seven)  other  visceral  arches, 
which  serve  for  the  support  of  the  respiratory  organs,  are  composed  of  several 
pieces,  and  united  ventrally  by  median  intercalary  pieces  (copulae).  Both  the 
gill  arches  and  the  hyoid  bear  cartilaginous  gill  rays.  In  the  Holocephali  the 
palatoquadrate  and  hyomandibular  fuse  together  and  with  the  cranial  capsule. 
The  mandible  thus  becomes  autostylic,  i.e.  articulates  directly  with  the 
cranium. 

In  the  cartilaginous  ganoids  (Acipenser,  Spatularia),  bony  Clements  begin 
to  take  part  in  the  formation  of  the  head.  The  cranial  capsule,  indeed, 
remains  for  the  most  part  cartilaginous ;  but  externally  there  are  a  number 
of  bony  plates,  which  cover  the  cranium  on  the  top  and  sides,  and  there 
is  also  developed  below  the  base  of  the  skull  a  long,  delicate,  dermal  bone 
(parasphenoid),  which  extends  forwards  to  the  ethmoidal  region  and  back  ward  s 
even  beyond  the  occiput.  The  palatoquadrate,  hyomandibular,  and  mandible 
are  also  covered  with  bone ;  and  the  fold  of  skin  covering  the  gill  clefts  is 
likewise  ossified  as  a  single  gill  cover  (operculum).  The  palatoquadrate 
and  hyomandibular  form  the  freely  movable  (hyostylic)  supports  of  the 
mandible. 

The  Dipnoi  resemble  the  cartilaginous  ganoids,  except  that  in  them  the 
palatoquadrate  and  hyomandibular  are  fused  with  the  cranium  (autostylic). 

In  the  scaly  ganoids  and  bony  fishes  a  more  or  less  complete  ossification  of 
the  cranial  capsule  and  visceral 
skeleton  occurs.  The  ossifica- 
tion begins  first,  as  in  the  carti- 
laginous ganoids,  with  dermal 
bones,  and  then  the  Substitution 
of  bony  substance  for  cartilage 
follows.  The  distinction  between 
dermal  bones  and  ossified  carti- 
lage (cartilage  bones)  can,  how- 
ever,  only  be  made  by  determin- 
ing  their  mode  of  development. 

In  the  cranium  proper  (Fig. 
23)  three  regions  are  distin- 
guishable — the  occipital  portion, 
the  auditory,  and  the  orbito- 
ethmoidal  regions.  The  hinder- 
most  or  occipital  region  consists  of  four  cartilage  bones: — (1)  The  lower 
occipital  bone  (occipitale  basilare,  basioccipital),  which  usually  contains  a 
persistent  remnant  of  the  notochord,  and  is  in  contact  with  the  vertebral 
column  with  its  deeply  hollowed  hinder  end  ;  (2,  3)  a  right  and  left  lateral 
occipital  (occipitalia  lateralia,  exoccipitals),  which  bound  the  greater  part  of 
the  foramen  magnum ;  and  (4)  an  upper  occipital  (occipitale  superius,  supra- 


Fig.  23. 

Craniiuii  of  the  Carp  (Cyprinus  mrjno,  Linn.).  AIS,  Ali- 
spheiioid  ;  BO,  Basioccipital ;  BSph,  Basisphenoid  ;  Ep,  Epiotic  ; 
Eth,  Etl)iiioid  ;  Exo,  Exoccipital ;  Er,  Frontal ;  io.  Interorbital ; 
OpO,  Opisthotic  ;  OSph,  Orbitosphenoid  ;  Prf,  Prefrontal ;  PrO, 
Proötic  ;  EtJ\  Postfrontal ;  SO,  öupraoccipital ;  Sq,  Squamosal ; 
Vo,  Vomer  (after  R.  Owen). 


12 


VERTEBRATA 


PHYLUM  VIII 


occipital),  which  belongs  to  the  cranial  roof,  often  thrust  between  the  parietal 
bones,  and  provided  with  a  vertical  median  crest. 

The  auditory  capsules  are  surrounded  laterally  by  several  pairs  of  bones 
often  completely  covered  by  the  facial  and  other  membrane  bones.  Among 
them  are  distinguished  immediately  in  front  of  the  exoccipitals  the  opisthotic 
(OpO),  the  epiotic  (EpO),  adjoining  the  latter  in  its  hinder  upper  part,  and 
the  proötic  {PrO)^  which  is  usually  pierced  by  the  trigeminal  nerve.  With 
these  bones,  which  form  the  auditory  capsule  proper,  there  is  connected  a 
bony  plate  on  each  side  above  and  in  front  of  the  opisthotic,  which  originates 
])artly  from  membrane,  partly  from  cartilage,  and  is  named  the  squamosal 
(Sq)  or  pterotic  (W.  K.  Parker) ;  the  mandibular  Suspensorium  (hyoman- 
dibular)  articulates  with  its  lower  face. 

The  lateral  Investment  of  the  middle  orbital  region  of  the  skull,  which 
sometimes  remains  cartilaginous  or  membranous,  and  is  sometimes  more  or 
less  completely  ossified,  consists  externally  of  facial  bones.  Two  pairs  of 
bones  can  be  distinguished  here,  posteriorly  the  alisphenoid  placed  just  in 
front  of  the  proötic,  and  anteriorly  the  orbitosphenoid ;  both  pairs,  but 
especially  the  orbitosphenoids,  often  fuse  together  completely  in  the  middle 

line.    The  base  of  the  skull 
A      Ft  ?«i  -l-o 

SOr 


^i^a 

Efh  \ 


Fyp.O 
Pt.O 


is  formed  by  a  large  dermal 
bone,  the  long,  sword- 
shaped  parasphenoid, 
which  abuts  behind  on  the 
basioccipital,  in  front  on 
the  vomer. 

The  roof  of  the  two 
hinder  regions  of  the  skull 
only  rarely  arises  in  carti- 
lage ;  it  usually  consists 
of  membrane  bones,  which 
are  intimately  connected 
with  the  cartilage  ele- 
ments.  There  are  thus 
intercalated  between  the 
supraoccipital  and  the 
squamosals  two  parietal 
Fig.  24.  boues,    aud    these    are 

Cranial  skeleton  of  the  Salmon.     The  persistent  cartilage  of  the    followed    in    front    by    the 

two  frontal  bones,  which 
often  fuse  together  into-a 
large  simple  plate.  By 
the  side  of  the  latter  and 
in  front  of  the  squamosal 
there  occurs  the  postfrontal 
(sphenotic,  ^y.  K.  Parker), 

which  belongs  to  the  membrane  series  in  the  Ganoids,  but  is  a  cartilage  bone 

in  the  Teleosteans.     There  is  also  occasionally  a  small  supraorbital  above  the 

eyes. 

The  anterior  ethmoidal  region  possesses  as  its   base  the  vomer  (Vo)  or 

ploughshare  bone,  which  also  forms  the  anterior  part  of  the  roof  of  the  hard 


craniuni  dotted  ;  the  bones  developed  from  cartilage  lettered  in  italics 
the  membrane  bones  in  Roman  type.  A,  Eye;  Ang,  Angular ;  Art, 
Artimlar;  Br.R,  Branchiostegal  ravs  ;  C.Hy,  Ceratohyal;  D,  Dentary  ; 
E.Hy,  Epihyal;  Ep.O,  EpiotÄc :  Eth,  Ethmoid;  Fr,  Frontal;  G.Hy,  Glosso- 
hyal;  H.Hy,  Hypohyal ;  HM,  Hyomandibular  ;  lOp,  Interoperculum  ;  Ju, 
Jugal;  L,  Lachrymal;  M.Pt,  Metapterygoid  ;  Ms.Pt,  Mesopterygoid ;  Mx, 
Maxiila  ;  Na,  Nasal ;  Op,  0))erculum  ;  Pa,  Parietal ;  Pmx,  Premaxilla  ; 
POp,  Preoperculum  ;  Ft,  Palatine  ;  Pt.O,  Pterotic  (with  squamosal)  ;  Qu, 
Quadrate;  S.O,  Supraoccipital ;  Sb.Or,  Suborbitals;  SOp,  Suboperculum  ; 
SOr,  Supraorbital ;  Sy,  Syviplectic  (after  Parker). 


CLASS  I 


PISCES 


13 


GHy 


UHy 


BrR 


palate.  From  the  vomer  on  either  side  there  slopes  upwards  and  outvvards  a 
prefrontal  bone  (ethmoidale  laterale,  W.  K.  Parker),  which  is  connected  above 
with  the  frontal  and  with  the  ethmoid  {Eth)^  which  surrounds  the  nasal 
capsule  above,  in  front,  and  partly  at  the  side.  One  or  more  small  ossifica- 
tions  above  each  nasal  opening,  which  are  sometimes  fixed  to  the  outer  face  of 
the  ethmoid,  are  termed  nasal  bones  or  nasalia  {Na). 

To  the  visceral  skeleton  (Figs.  24,  25)  belong  the  jaw  apparatus,  the 
facial  bones,  and  the  gill  arches.  The  hyomandibular  is  in  close  connection 
with  the  hinder  part  of  the  palatoquadrate.  Thus  arises  the  so  -  called 
Suspensorium,  which,  as  support  of  the  mandible,  is  movably  connected  by 
ligaments  with  the  skull.  The  quadrate  articulates  below  with  the  mandible, 
and  is  firmly  fixed  above  with  the  sj^mplectic  which  occurs  at  the  lower  end  of 
the  hyomandibular.  From  the  quadrate  there  extends  forwards  the  angularly 
bent  ectopterygoid,  upwards  the  metapterygoid,  and  again  forwards  the  meso- 
pterygoid,  of  which  the  anterior  end 
is  connected  with  the  palatine.  The 
latter  is  fixed  by  cartilaginous  liga- 
ments at  its  anterior  border  to  the 
vomer  and  the  ethmoidal  region. 

In  front  of  the  palatine  on  each 
side  there  occur  two  pairs  of  rather 
large  bones,  which  are  usually  pro- 
vided  with  teeth.  The  anterior  of 
these,  the  premaxilla  or  intermaxilla, 
meets  its  fellow  of  the  opposite  side  in 
a  Symphysis  in  front  of  the  ethmoid 
region.  The  hinder  bone,  or  maxilla, 
is  sometimes  connected  with  the  quad- 
rate through  the  Intervention  of  a 
slender  jugal  or  supramaxillary. 

The  lower  jaw  (mandibula)  consists 
of  the  articular,  a  postero  -  inferior 
anffular,    which    often    remains    carti- 

,       .  Till  •       •       1       •  Right  half  of  the  hyoid  and  branchial  arches  of  the 

laginOUS,   and   the   large   prinCipal   piece  Perch  (Perca  flumatiUs,  Linn.).     BtR,  Branchiostegal 

or     rlpntarv     ^dpntalp^       whlVh      imnallv  rays  ;  Co,  Copulae  of  branchial  arches  ;  E'Hj/,  Epihyal ; 

or     uentary     ^^uentaie;,     wnicn     USUaiiy  ^^^^  Olossohyal ;  HHy,  Hypohjal ;  IHy,  Inlerhyal  ; 

bears  teeth.       On    the    inner    side  there  -P/is,  Upper  pharyngeal  bones;    Ulfy    Urohyal;    II, 

,  .       ,    ,  Hyoid  arch ;  III-\  I,  Branchial  arches  (after  Cuvier). 

IS  also  a  membrane  bone,  the  spienial 

(or  operculare),  which  not  unfrequently  bears  teeth,  and  sometimes  (as  in  the 

Crossopterj^gii)  consists  of  two  or  more  bony  pieces. 

Several  opercular  bones  arising  from  a  fold  of  skin  attain  a  remarkably 
great  development  both  in  the  Ganoidei  and  Teleostei.  The  foremost,  or 
preoperculum,  is  usually  a  rather  long,  slender,  slightly  arched,  bony  plate, 
which  is  connected  above  with  the  hyomandibular,  below  with  the  quadrate. 
Behind  this  there  is  an  operculum,  usually  of  relatively  large  size,  bounded 
below  by  a  suboperculum,  often  also  by  an  interoperculum,  which  is  connected 
with  the  hinder  end  of  the  mandible. 

A  variable  number  of  small  dermal  bones  or  suborbitals  (suborbitalia) 
form  the  arched  posterior  and  inferior  margin  of  the  orbit.  The  supraorbital 
(SOr)  above  and  the  lachrymal  (L)  in  front  are  small  dermal  bones,  which  are 
in  close  connection  with  the  cranium,  but  are  only  rarely  developed. 


Fig.  25. 


14  VERTEBKATA  phylum  viii 

The  gill  apparatus  (Fig.  25)  of  the  Ganoidei  and  Teleostei  does  not  differ 
essentially  from  that  of  the  Selachii,  except  that  the  gill  rays  supported  by 
the  hyomandibular  in  the  latter  are  replaced  here  by  opercular  plates,  while 
behind  the  hyoid  there  are  never  more  than  five  (rarely  four)  bony  arches, 
and  the  branchiostegal  rays  of  the  hyoid  arch  become  robust  bony  pieces  or 
plates.  The  hyoid  is  subdivided  into  an  upper  epihyal,  a  middle  ceratohyal, 
and  a  small  hypohyal  (basihyal)  consisting  of  two  pieces ;  the  median 
connecting  piece  (copula)  is  extended  more  or  less  forwards  into  the  tongue  as 
a  glossohyal,  and  is  sometimes  covered  with  teeth,  sometimes  toothless ;  a 
second  segment  of  bone  belonging  to  the  copula,  directed  backwards,  is  named 
urohyal.  The  gill  branches  (branchialia)  also  consist  each  of  three  pieces  (epi-, 
cerato-,  and  hypo-branchiale),  connected  in  the  median  line  with  copulae,  and 
beset  throughout  their  entire  length  with  delicate  cartilaginous  rays,  some- 
times also  on  their  inner  side  with  tooth-like  prominences  or  spines.  With 
the  epibranchials  are  also  connected  the  short  upper  pharyngeal  bones,  which 
often  bear  teeth.  The  last  branchial  arch  is  usually  more  or  less  modified, 
and  forms  the  lower  pharyngeal  bones. 

The  limbs  of  fishes  comprise  not  only  the  paired,  but  also  the  unpaired  fins, 
since  both  function  as  organs  of  locomotion.  While,  however,  the  latter  are 
exclusively  dermal  structures,  the  paired  fins  belong  at  least  in  part  to  the 
internal  skeleton,  and  correspond  with  the  extremities  of  the  higher  Vertebrata, 
the  pectoral  fins  with  the  anterior,  the  pelvic  or  ventral  fins  with  the  posterior 
limbs. 

Both  the  pectoral  and  pelvic  fins  are  connected  with  originally  cartilaginous 
arches  (pectoral  and  pelvic  girdles),  which  may  become  ossified  and  covered 
with  bony  plates  in  variable  number.  They  are  entirely  absent  only  in 
Amphioxus  and  the  Cyclostomi.  Except  in  the  Selachii,  the  pectoral  girdle  is 
usually  fixed  to  the  supraoccipital  or  squamosal  bone.  In  the  Selachii  (Fig. 
28,  ^)  it  forms  a  simple  arch  of  cartilage,  ventrally  closed,  situated  behind  the 
gills,  its  upper  ends  either  terminating  freely  (sharks)  or  connected  with  the 
vertebral  column  (rays) ;  it  is  bent  upwards  at  the  Insertion  for  the  fins,  and 
pierced  by  nerve  foramina.  In  many  Ganoids  (Chondrostei,  Heterocerci, 
Crossopterygii)  the  primary  cartilaginous  pectoral  girdle,  divided  into  two 
pieces  by  a  ventral  suture,  is  covered  on  each  side  by  three  membrane  bones, 
of  which  the  median  and  largest  is  termed  clavicula,  the  lower  one  infra- 
clavicula,  the  upper  one  supraclavicula.  The  latter  is  sometimes  divided  into 
two  pieces,  of  which  the  upper  is  named  post-temporal.  In  the  other  Ganoids 
and  the  Teleosteans  the  primary  pectoral  girdle  is  entirely  replaced  by  ossifica- 
tion.  The  girdle  is  here  formed  of  two  bones  united  by  jagged  suture  on  the 
postero-internal  face  of  the  very  large  clavicle,  the  hinder  element  homologous 
with  the  scapula,  the  antero-anterior  element  with  the  coracoid.  In  several 
families  there  is  also  a  third,  slender,  arched  bar  {Spangenstück  or  precoracoid), 
extending  downwards  and  inwards  to  the  lower  end  of  the  clavicle. 

The  clavicle  is  always  the  principal  bone  of  the  pectoral  girdle  in  the 
Teleostei,  and  its  size  and  form  vary  remarkably.  A  supraclavicle  and  a 
post-temporal  (Pt)  rest  on  its  upper  end ;  while  an  ordinarily  slender  acces- 
sory  dermal  bone,  the  post-clavicle,  overlaps  it  behind. 

The  pectoral  fins  themselves  can  only  be  homologised  in  part  and  with 
difficulty  with  the  anterior  extremities  of  the  higher  Vertebrata.  If  we 
accept,  with  Gegenbaur,  the  biserial  fin  of  Ceratodus  (Fig.  26)  as  the  basal 


PISCES 


15 


Fig.  26. 

Pectoral  fln  of  Cerutodus  forsteri,  Kreft't. 
Queensland,  a,  Basal  cartilage  ;  b,  Fin  ;  C, 
arch. 


Recent ; 
Pectoral 


type  most  closely  approaching  the  primitive  fiii  (archipterygium),  we  observe, 
fixed  to  the  mainly  cartilaginous  pectoral  girdle,  two  large  pieces  of  cartilage, 
followed    by    a    long    row    of    smaller 
cylindrical    or    Square    segments,    from 


which    cartilaginous    rays    diverge    on 

each  side.    The  extinct  Selachian  genus 

Fleuracanthus  also   possessed   a   central 

axis  in  the  pectoral  fin  ;  but  in  all  the 

other    Selachii    the   cartilaginous   rays 

are  in  one  series.     In  the  latter  there 

are  three  large  adjacent  basal  cartilages, 

the  promeso-,   and  metapterygium,   connected  with  the  pectoral  girdle,  and 

each  bears  several  rays  consisting  of  pieces  of  cartilage  (Fig.  27).  The 
metapterygium  is  always  the  stoutest ;  the  two  others  are 
often  much  reduced  or  may  even  be  completely  absent.  The 
dermal  part  of  the  fin  is  itself  always  supported  by  numerous 
horny  filaments  in  pairs. 

In  the  Ganoidei,  and  still  more  in  the  Teleostei,  the 
Segments  radiating  from  the  basal  pieces  are  extremely 
degenerate.  Polyptenis  (Fig.  28,  B)  retains  the  three  basal 
pieces  of  the  Selachii,  but  in  most  of  the  other  Ganoids  the 
metapterygium  forms  almost  the  sole  support  for  the  fin — 
the  meso-  and  propterygium  are  atrophied.  Two  or  three 
rays,  however,  enter  the  same  row  as  the  basal  pieces  and 
are  connected  with  the  Shoulder  girdle. 

In  the  same  manner  the  base  of  the  pectoral  fin  in  the 
Teleostei  (Fig.  28,  G)  consists  almost  invariably  of  four  to 
five  similar,  flattened,  bony  pieces,  with  which  a  varying 
number  of  short  little  cartilages  are  connected.  In  propor- 
tion  as   the    peripheral   parts   of  the   primary   fin   skeleton 

degenerate,   ossified   fin  rays  are  developed  as  secondary  structures  on  each 

side  of  the  dermal  fin  expansion. 

The  so-called  pelvic  girdle  of  the  hinder  extremity  is  considerably  simpler 

than  the  pectoral  girdle.     Among  the  Selachii  it  appears  as  a  paired  or  un- 

scZ 


l'fctoral  tin  o(  S<iiui- 
tina  iniUiaris,  Risso. 
With  outer  dermal  rays 
reiiioved.  ms,  Meso- 
pt^rygimn  ;  mt,  Meta,- 
pterygimu ;  p,  Pro- 
pterygium ;  r,  Radiais. 


Pectoral  arch  and  tin  of  ^,  Hcphinchus  (Selachii).  B,  Folypterus  (Ganoidei).  C,  Saltno  (Teleostei).  d,  Clavicle  ; 
CO,  Coracoid  ;  fs.  Outer  dermal  fln  rays  (exoskeletal) ;  ms,  Mesopterygium  ;  mt,  Metapterygium  ;  p,  Pi-opterygium  ; 
/><■/,  Postclavicle  ;  pt,  Post-temporal ;  r.  Basal  rays  (endoskeletal)  ;  sc,  Scapula  ;  sd,  Sai>raclavicle. 


paired  rod  pierced  by  nerve  foramina,  either  lying  in  the  longitudinal  axis  of 
the  body  or  forming  an  arch,  convex  in  front,  concave  behind.  To  this  girdle 
are  attached  the  two  basal  pieces  (pro-  and  metapterygium)  of  the  pelvic  fin, 
which  l)ear  a  single  series  of  cartilaginous  rays  on  their  outer  side.     Among 


16  VERTEBKATA  phylum  viii 

the  Ganoids  Folypterus  alone  retains  two  small  pieces  of  cartilage  as  remnants 
of  a  pelvic  girdle ;  in  all  other  ganoids,  as  well  as  in  the  Teleostei,  the  pelvic 
girdle  is  completely  wanting,  but  the  metapterygium  of  each  side  attains  a 
remarkable  size,  and  forms  the  whole  fin  support,  sometimes  as  a  simple 
elongated  bone,  sometimes  as  a  plate  forking  into  two  pieces.  In  the  Ganoidei 
the  rays  belonging  to  the  fin  skeleton  are  occasionally  bony ;  in  the  Teleostei, 
on  the  other  hand,  they  are  usually  cartilaginous,  much  reduced,  sometimes 
indeed  completely  absent.  The  membrane  of  the  fin  itself  comprises  numer- 
ous  articulated  bony  rays.  In  the  Dipnoi  the  pelvic  girdle  exhibits  a 
peculiar  development.  It  consists  of  an  unpaired,  quadrangular  plate  of 
cartilage,  which  is  produced  forwards  into  a  long  process,  and  supports  the 
cartilaginous  axis  of  the  biserial  fin. 

While  the  pelvic  fins  of  the  Selachii,  Ganoidei,  and  Dipnoi  are  always 
situated  near  the  hinder  end  of  the  abdominal  cavity,  they  are  often  displaced 
forwards  in  the  Teleostei,  becoming  even  connected  with  the  pectoral  girdle. 
Through  this  forward  displacement  of  the  pelvic  fins  there  arise  striking 
modifications  in  the  general  aspect  of  the  bony  fishes,  which  are  of  great 
importance  as  a  means  of  Classification. 

The  fossil  bones  of  fishes  can  generally  be  recognised  with  certainty  by 
their  external  form.  Their  outer  surface  usually  exhibits  a  characteristic 
aspect,  on  account  of  numerous  small  rugosities,  open- 
ings  of  canals,  and  striations ;  while  tubulär  bones  with 
a  medullary  cavity  are  here  entirely  wanting.  From 
the  histological  point  of  view,  the  bones  of  many  fishes 
are  noteworthy  for  the  absence  or  very  sparse  develop- 
FiQ.  29.  ment  of  bone  cells. 

Ear    bones    (otoliths)    of    a  tti         m  i  ±   tii       /-rt-        nrw  i 

Teieostean  fish,  outer  (.4),  and  i^  ossil  ear  boues  or  otoliths  (r  lg.  29)  are  also  some- 

LältdS'''Size^^*°^^^^^^    times  found  with  the  hard  dermal  structures  and  the 
skeleton.     These  do  not  consist  of  phosphate,  but  of 
carbonate  of  lime,  and  exhibit  great  variety  in  their  shape,  the  sculpturing  of 
their  surface,  and  the  nature  of  their  borders. 

Since  the  work  of  Aristotle,  the  Classification  of  fishes  has  been  based 
chiefly  on  the  characters  of  the  internal  and  external  skeleton,  on  the  nature 
and  arrangement  of  the  fins,  and  on  the  organs  of  respiratioii.  Artedi, 
Bonaparte,  Lac^j^ede,  Cuvier,  and  Valenciennes  distinguished  the  cartilagin- 
ous fishes  from  those  provided  with  a  bony  skeleton,  and  again  subdivided 
both  sections  in  different  ways  into  several  groups.  In  this  Classification  no 
reference  was  made  to  fossil  fishes,  although  sharks'  teeth,  for  example,  teeth 
of  various  bony  fishes  (the  so-called  bufonites,  chelonites,  toad-stones,  and 
snakes'  eyes),  and  also  complete  skeletons  from  different  localities  (e.g. 
Eisleben,  Solenhofen,  Oeningen,  Monte  Bolca,  and  Glarus)  were  already 
known  in  the  eighteenth  Century  and  numbers  of  them  had  been  described. 
The  epoch-making  work  of  L.  Agassiz  (1833-1844)  aiforded  a  complete  survey 
of  all  the  fossil  fishes  known  at  the  time,  and  also  established  on  scale 
characters  a  new  subdivision  of  the  fishes  into  four  principal  groups,  namely, 
Placoidei,  Ganoidei,  Cycloidei,  and  Ctenoidei.  Johannes  Müller  united  the  two 
latter  groups  under  the  denomination  of  Teleostei  (bony  fishes),  defined  the 
ganoids  more  precisely,  and  subdivided  the  cartilaginous  fishes  into  four 
sub-classes,  namely,  Leptocardii,  Cyclostomi,  Selachii,  and  Dipnoi.  The  most 
important  of  the  later  changes  in  Classification  consist  in  the  establishment 


SUB-CLASS  I 


SELACHII 


17 


of  the  Leptocardii  (Amphioxus)  and   Cyclosfomi  (lampreys   and   hag-fishes)   as 

independent  classes  equivalenfc  to  that  of  the  fishes,  ^^ 

and  in  the  closer  union  of  the  ganoids  and  bony  fishes, 

which    are    frequently    grouped    under    the    common 

denomination  of  Teleostomi.     The  class  of  fishes  in  its 

restricted  sense  thus  comprises  the  four  still-existing 

sub-classes  of  Selachii,  Dipnoi,  Ganoidei,  and  Teleostei  ; 

while  to  these  must  be  added  the  extinct  sub-classes 

of  Ostracodermi  (or  Ostracophori)  and  Arthrodira,  which 

are  restricted  to  the  Palaeozoic. 

No  fossil  remains  of  Leptocardii  are  known.  It 
must  also  be  remarked  that  there  is  no  satisfactory 
evidence  of  extinct  representatives  of  the  Cyclostomi 
or  Marsipohranchii.  Certain  annelid  jaws  from  the 
Palaeozoic  formations,  known  as  Conodonts,  were  once 
erroneously  supposed  to  be  teeth  of  this  class  (see  vol.  i. 
p.  255).  The  problematical  organism  from  the  Old 
Red  Sandstone  of  Achanarras,  Caithness,  named  Palaeo- 
spondylus  gunni'^  by  Traquair  (Fig.  30),  is  likewise  very 
doubtfully  placed  here.  The  largest  specimens  of  this 
form  do  not  exceed  0*05  m.  in  length.  The  skull 
terminates  in  front  in  a  ring  of  calcified  cirri  (d.c,  l.c, 
v.c),  which  Surround  a  large  bilaterally  symmetrical 
orifice  {ii).  Behind  the  skull  there  extends  backwards 
a  pair  of  elongated  cartilages  («),  usually  lying  in  the 
fossil  parallel  with  the  vertebral  column.  There  are 
vertebral  centra  in  the  form  of  broad  rings  ;  in  the 
abdominal  region  these  bear  short  and  stout  neural 
spines,  but  no  ribs ;  in  the  caudal  region  the  neural 
and  haemal  spines  are  very  slender,  while  the  former  chordai  portion  orskuii;  t.p, 

■^  ,1  ,1        A    ,.  1     T   j^'       ji        t   1     j^         •         Trabeculo - palatine   portion   of 

are  longer  tnan  the  latter  and  distmctiy  dichotomise   skuii;  r.c,  Ventral  cim;  x,Pro- 
at  the  distal  end.     There  is  no  undoubted  evidence  of  f/f(ä?t^rSS^ 
paired  limbs. 


Fig.  30. 

Palaeospondyhis  gunni,  Tra- 
quair. Lower  Old  Red  Sand- 
stone ;  Caithness.  a,  Separate 
sniall  lobe  ;  b,  Anterior  depres- 
sion  or  fenestra  ;  c,  Posterior  de- 
pression  or  fenestra  ;  d.c.  Dorsal 
cirri ;  l.c.  Lateral  cirri ;  n,  Sup- 
posed narial  opening;  j>.a,  Para- 


Sub-Olass  1.     SELACHII.     Cuvier. 

(JElasmobranchii,  Bonap. ;  Chondropteri/gii,  Günther;  Placoidei,  Ag.) 


Eiidoskeleton  cartilaginous ;  exoskeleton,  wlien  present,  strudwally  identical 
with  the  teeth  (placoid  scales).  Usually  five  {rarely  six  or  seven)  pairs  of  hranchial 
arches,  the  clefts  exposed  or  covered  only  by  a  flap  of  skin,  without  operculum.  In 
the  living  forms — optic  nerves  not  decussating  but  forming  a  chiasma ;  bulbus 
arteriosus  of  the  heart  with  two,  three  or  more  series  of  valves  ;  air-bladder  absent  ; 
intestina  with  a  spiral  valve  ;  ovaries  with  few  large  ova. 

The  unsegmented  cartilaginous  cranium  of  the  Selachii  is  more  or  less 
imperfectly  hardened  with  polygonal  granules  of  phosphate  of  lime ;  but  the 
vertebrae  are  very  variously  calcified,  can  thus  be  readily  preserved  in  a  fossil 
State,  and,  according  to  Hasse,  display  features  of  special  importance  for  the 

^  Dean,  B.,  The  Devonian  "Lamprey  "  Palaeospondylus  gunni,  Traquair  (Mem.  N.Y.  Acad.  Sei. 
vol.  II.  pt.  1),  1900.  Bibliography. — Traquair,  R.  H.,  A  still  further  contribution  to  cur  knowledge 
of  Palaeospondylus  (Proc.  Roy.  Pliys.  Soc.  Edinb.  vol.  XII.),  1894. 

VOL.  II  C 


18 


PISCES 


CLASS I 


purposes  of  Classification.  In  the  sharks  and  skates  the  pterygoquadrate 
cartilage  of  the  upper  jaw  is  movably  suspended  from  the  craniuni,  and  the 
vertebral  axis  is  often  distinctly  segmented ;  in  the  Chimaeroids  (Holocephali) 
the  Upper  jaw  is  fused  with  the  cranium  and  the  mandible  articulates  directly 
with  this,  while  the  notochord  remains  unsegmented,  so  that  the  vertebrae 
are  always  indicated  only  by  the  arches. 

Among  the  sharks  (Plagiostomi)  the  Notidanidae  exhibit  the  most 
primitive  vertebral  axis  (Fig.  31).  Here  regularly  spaced  thickenings  of  the 
notochordal  sheath  constrict  the  chord  itself  and  form  divisions  pierced 
through  the  middle  {Diplospondyli).  The  term  Cydospondyli  is  applied  by 
Hasse    to    those    vertebrae    in   which   a   calcified    ring  appears    uniting    the 


•...ch 


Fig.  31. 

Longitudinal  seetion  of  the  anterior  part  of  the 
vertebral  column  of  Heptanchus.  ch,  Notochord  ; 
d,  Incipieiit  calcified  double -cone  (basis  of 
centrum);  iv,  Intervertebral  space  filled  with 
notochord  ;  v),  Constriction  of  notochordal  sheath 
(after  Kölliker). 


Fig.  32. 


Longitudinal  seetion  of  the  tectospon- 
dylic  vertebral  column  of  Squatina 
angelus,  Linru  ch,  Notochord  ;  d,  Cal- 
cified double -cone  (basis  of  centrum); 
iv,  Intervertebral  space  ;  w,  Vertebral 
centra  with  concentric  calcified  rings 
(after  Hasse). 


ordinarily  calcified  anterior  and  posterior  borders  of  the  primitive  constricted 
centrum  (Fig.  33,  A).  When  additional  calcified  lamellae  concentric  with  the 
first  are  developed  in  the  intravertebral  space,  the  Tedospondyli  (Figs.  32,  33,  B) 
are  recognised ;    when,   on  the  other  band,  calcified  plates  or  ridges  radiate 

from  the  centre  to 
the  periphery,  the 
vertebrae  are 
termed  asterospon- 
dylic,and  thegroup 
Aster ospondyli  (Fig. 
„    33,  C). 

With  the  verte- 
brae    there    occur 
P    most      abundantly 
in    the  fossil  State 
teeth,     fin     spines, 
T,.  ^.       ,.   ,     ,.     ,,  and       occasionallv 

Diagrammatic  vertical  seetion  tlirough  the  middle  of  Selachian  vertebme  of  the  j  ^  i     ^     "^ 

cydospondylic  {A),  tectospoi\dylic  {B),  &m\  asterospondylic  (C)  tyi)^.s.     C    Space  for  Clermal  platCS. 

notochord;  D    Central  calcified  ring  or  double  cone;  E,  Elastica  externa;  H,  ftharlr«'  tPPth      nrP 

Haemal  arch  ;  N,  Neural  arch  (after  Hasse).  onarKS  leein     are 

among  the  fossils 
which  have  been  longest  known,  and  are  frequently  mentioned  in  the  older 
writings  under  the  names  of  glossopetrae,  birds'  tongues,  and  snakes'  tongues. 
The  form  of  the  teeth  is  very  variable,  often  sharply  pointed  with  cutting  edges, 
Single-  or  many-cusped,  but  frequently  also  pavement-like,  with  a  flattened, 
bluntly  conical  crown.  They  consist  essentially  of  vasodentine,  dentine,  and 
structureless  enamel  (ganodentine).  Except  perhaps  in  some  extinct  Acan- 
thodii,  they  are  always  fixed  by  ligament,  never  fused  with  the  supporting  jaw. 


Fio.  33. 


SUB-CLASS  I 


SELACHII 


19 


Order  1.     PLBUROPTBRYGII.     Dean.^ 

Endoskeleton  well  calcified.  Notochord  apparently  not  segmented.  -  Pterygo- 
quadrate  arcade  movably  articulated  with  the  cranium.  Orbit  surrounded  with  a 
ring  of  tliin  plates  of  dentine.  Paired  fins  supported  hy  unjointed,  parallel  radial 
cartilages,  ivhich  may  he  partly  fused  at  the  hase,  but  extend  directly  outwards  to  the 
edge  of  the  fin  membrane.     Pelvic  fins  of  male  without  daspers. 

According  to  Bashford  Dean  and  Smith  Wood  ward,  the  Pleuropterygii 
include  the  most  primitive  known  representatives  of  the  Selachii.  Their 
vertebral  axis  seems  to  have  remained  unsegmented,  and  in  the  typical  genus 
Cladoselache,  the  tail  is  strongly  heterocercal.  Their  teeth  are  of  the  form 
commonly  known  as  Cladodus  (Fig.  35)  in  the  Carboniferous  formations,  and 
several  series  must  have  been  functional  at  one  and  the  same  time. 

Cladoselache,  Dean  (Fig.  34).  The  only  well-defined  genus  hitherto  dis- 
covered.    The  form  is  elongated  and  round-bodied,  with  a  short  blunt  snout  and 


Fig.  34. 

Restoratiou  of  Cladosela,che  newberryi,  Dean.     Cleveland  Shale  (Upper  Devonian) ;  Ohio.     An  anterior 
dorsal  fin  has  been  discovered  since  this  illustration  was  inade  (after  Dean). 

forwardly  placed  eye.     Circumorbital  ring  consisting  of  several  series  of  thin, 

irregularly  quadrangular  small  plates.     Mouth  terminal,  and  hyomandibular 

cartilage  slender.     Teeth  largest,  longest,   and   most  acutely  pointed  at  the 

Symphysis  of  the  jaw,  smallest  and  shortest  at  the  angle 

of  the  mouth.     Each  tooth  with  one  principal  cusp  and  a 

variable  number  of   lateral   cusps,   fixed   on   the   anterior 

border  of  a  horizontally  expanded  base  ;  the  base  of  each 

tooth    overlapped    by  its    successor    behind.     Paired   fins 

lappet-like,  the  pelvic  pair  with  somewhat  extended  base 

line.     Two  low  dorsal  fins,  without  spine.     Anal  fin  not 

yet    observed.       A    short    dermal    expansion    forming    a 

horizontal  keel  on  each  side  of  the  caudal  pedicle  just  in   boniferöus 

advance  of  the  strongly  heterocercal  caudal  fin.     Skin  more   ^™jf '    ^'^^^''^   ^^^^«^ 

or   less  armoured   with  minute   lozenge-shaped   denticles, 

which  are  apparently  not  enamelled.      C.  kepleri,  C.  fyleri,  and  other  species 

sometimes  two  metres  in  length,  from  the  Cleveland  Shale  of  Ohio. 

The  teeth  termed  Cladodus  (Fig.  35)  occur  isolated  in  the  Lower  Carboni- 
ferous of  England,  Scotland,  Ireland,  Belgium,  Eussia,  India,  and  North 
America.  They  are  also  recorded  from  the  Upper  Carboniferous  both  of 
Europe  and  North  America,  but  it  is  difficult  to  distinguish  them  from  those  of 
the  genus  Sphenacanthus  (p.  27).     It  is  possible,  however,  that  these  teeth  do 

^  Dea7i,  Bashford,  Contribiitions  to  tlie  Morphology  of  Cladosdadie  (Jouru.  Morpliol.  vol.  IX.), 
1894.— A  new  Cladodout  from  the  Ohio  Waverly  (Trans.  New  York  Acad.  Sei.  vol.  XIII.),  1894. 
—The  Finfold  Origin  of  the  Paired  Limbs  (Anat.  Anz.  vol.  XI.  No.  22),  ]896. 


Fig.  35. 

Cladodus    striatns,    Ag. 
Tooth,  natural  size.     Car- 
Limestone ; 


20  PISCES  CLASSi 

not  all  belong  to  the  Pleuropterygii.  Cladodus  neilsoni,  from  the  Calciferous 
Sandstones  of  East  Kilbride,  Lanarkshire,  is  known  by  the  imperfect  head 
associated  with  a  very  remarkable  pair  of  pectoral  fins  (Traquair,  Trans.  Geol. 
Soc,  Glasgow,  vol.  xi.  1897,  p.  41). 

The  genera  Dicentrodus,  Traquair ;  Fhoebodus,  Lambdodus,  Hyhodadodiis,  St. 
John  and  Worthen  ;  Dicrenodus,  Komanowsky  (Carcharopsis,  Ag. ;  Fristidadodus, 
M'Coy),  are  founded  on  detached  teeth,  mostly  from  the  Carboniferous  Lime- 
stone, of  uncertain  afiSnities.  Protodus,  Smith  Woodward,  founded  on  teeth 
from  the  Lovver  Devonian  of  Canada  and  Scotland,  may  also  be  mentioned  as 
a  possible  Pleuropterygian. 


Order  2.     ACANTHODII.     Agassiz.i 

Endoskeleton  well  calcified,  with  dermal  and  memhrane  calcifications  in  the  region 
of  the  skull  and  pedoral  arch.  Pterygoquadrate  arcade  movahly  articidated  with  the 
cranium.  Orbit  surrounded  with  a  ring  of  thin  plates  of  dentine.  Teeth,  when 
present,  firmly  fixed  to  the  calcified  sheathing  plates  of  the  pterygoquadrate  and 
mandibular  cartilages.  Endoskeletal  cartilages  of  all  the  fins  much  reduced,  and  the 
dermal  expansion  almost  or  completely  destitute  of  rays  ;  each  of  the  fins  except  the 
caudal  with  a  robust  anterior  spine  implanted  in  the  flesh.  Felvic  fins  of  male 
without  daspers.  Dermal  armature  of  trunk  consisting  of  small,  closely  arranged, 
quadrate  granules,  which  also  extend  over  the  greater  portion  of  the  fins  ;  lateral  line 
passing  between  two  series  of  the  granules. 

Two  families  of  this  order  are  distinguished,  the  Acanthodidae  with  one 
dorsal  fin,  and  the  Diplacanthidae  with  two  dorsal  fins.  These  fishes  were 
originally  assigned  to  the  Ganoidei  by  Agassiz,  but  their  close  relationships  to 
the  Selachii  were  observed  by  Lütken,  Fritsch,  and  Huxley.  While,  however, 
they  were  arranged  by  Lütken  and  Fritsch  among  the  Selachii,  they  were 
regarded  by  Huxley  as  intermediate  between  the  Ganoidei  and  Selachii. 
Later  researches  by  Traquair,  Smith  Woodward,  and  Reis  seem  to  have 
justified  the  reference  of  the  order  to  the  Selachii. 

The  Acanthodii  comprise  not  only  a  number  of  more  or  less  completely 
known  genera  from  the  Devonian,  Carboniferous,  and  Permian  formations, 
but  also  a  few  genera  which  are  still  represented  only  by  isolated  fin  spines 
(Haplacanthus,  Ag. ;  Homacanthus,  Ag. ;  Gyracanthus,  Ag. ;  and  Machaeracanthus, 
Newberry).  The  close  resemblance  between  the  spines  of  Climatius  and  the 
Ichthyodorulites  named  Onchus  suggests  that  at  least  some  of  the  latter,  which 
ränge  throughout  the  Upper  Silurian  and  Lower  Devonian,  also  belong  to 
Acanthodians. 

Family  1.     Acanthodidae.     Smith  Wood  ward. 

A  Single  dorsal  fin.  Free  spines  between  paired  fins  usually  absenf,  sometimes 
'represented  by  one  rudimentary  pair.     Lower  Devonian  to  Lower  Permian. 

^  Fritsch,  A.,  Fauna  der  Gaskohle  in  Böhmen,  vol.  II.  Prague,  1%%^.— Huxley,  T.  H.,  Prelimi- 
nary  Essay  upon  the  Systeraatic  Arrangement  of  the  Fishes  of  the  Devonian  Epoch  (Meni.  Geol. 
Snrv.  dec.  x.),  \%&\.—Kner,  R.,  Sitzungsb.  k.  Akad.  Wiss.  Wien,  Math.-naturw.  Gl.  vol.  LVII.  p. 
290,  l%Q9>.—Poiorie,  J.,  On  the  earliest  known  Vestiges  of  Vertebrate  Life  (Trans.  Edinb.  Geol.  Soc. 
vol.  IX.),  1869.— ßoemg/-,  F.,  lieber  Acantlwdes  gracilis  (Zeitschr.  deutsch,  geol.  Ges.  vol.  IX.),  1857. 
—Reif,  0.,  Zur  Kenntniss  des  Skelets  der  Aeanthodineu  (Geogn.  Jahreshefte,  München),  1890  and 
189L—Traquair,  R.  IL,  Geol.  Mag.  1888,  p.  511,  and  1889,  p.  17. 


SUB-CLASS  I 


SELACHII 


21 


Fig.  36. 

Mesacanthus  mifchelli,  Eg.  sp.     Lower  Old  Red  Sandstone  ;  Farnell, 
Forfarshire.     Nat.  size  (after  Egerton). 


Mesacanthus,  Traquair  (Fig.  36).     A  gracefully  fusiform  fish  with  slender 

spines.     Circumorbital  ring  of  four  plates.     Pelvic  fins  not  much  smaller  than 

the  pectorals,  about  mid- 

way    between    these    and 

the  anal ;  a  pair  of  minute 

spines  between  the  paired 

fins.     Dorsal  fin  more  or 

less  opposed  to  the  anal, 

but  not  in  advance  of  it. 

Mesacanthus    mitchelli, 

Egert.  sp.  (Fig.  36);   31. 

peachi,    Egert.     sp. ;    and 

M.  pusillus,  Ag.  sp.,  from 

the  Lower  Old  Eed  Sand- 
stone   of    Scotland.       M. 

affinis,  Whiteaves  sp.,  an  equally  small  species  from  the  Upper  Devonian  of 
Scaumenac  Bay,  Province  of  Quebec,  Canada. 

Acanthodes,  Ag.  (Acanthoessus,  Ag. ;  Holacanthodes, 
Beyr. ;  Traquairia,  Fritsch),  (Figs.  37,  38).  A  more 
elongated  fish  with  similarly  remote  dorsal  fin,  but 
the  pelvic  fins  relatively  small  and  advanced  forwards, 
the  pectorals  larger,  and  intermediate  spines  absent. 
Teeth  minute  or  absent ;  circumorbital  ring  of  four 
more  or  less  sculptured  plates.  Pectoral  fin  spine 
supported  by  a  hollow,  mesially  constricted  element 
(Fig.  37,  b),  which  abuts  against  the  side  of  its  proximal 
end ;  a  close  series  of  short,  fine  dermal  rays  (r )  some- 
times  appearing  below  this  in  the  fin  membrane.  Scales 
smooth.  Ranging  throughout  the  Carboniferous  in 
Scotland,  the  Goal  Measures  in  England  and  North 
America,  and  the  Lower  Permian  in  France,  Germany, 
Bohemia,  and  Siberia.  A.  bronni,  Ag.,  the  typical 
species,  about  0*3  m.  in  length,  from  the  Rothliegende 

of  Rhenish  Prussia  (Lebach  and  Saarbrücken).     A.  gmcilis,  Beyr.  (Fig.  38), 

from    Klein    Neundorf,    Silesia, 

probably     identical     with     the 

latter.     A.  wardi,  Egert.,   from 

Goal      Measures,      Longton, 

Staff'ordshire. 

Cheiracanthus,  Ag.     Like 

Acanthodes,  but  dorsal  fin  arising 

in  advance  of  anal,  and   scales 

sculptured.     C.  murchisoni,  Ag., 

and   other  species  from   Lower 

Old  Red  Sandstone,  Scotland. 
Acanthodopsis,    Hancock   and 

Atthey.     Jaws  with  few  large, 

laterally   compressed,    triangulär   teeth.       A.   wardi 

Measures  of  Northumberland  and  Midlothian. 


Acanthodes  wardi,  Eg. 
Skeletal  parts  of  pectoral  fin, 
nat.  size.  Goal  Measnres  ; 
England,  h,  Hollow  basal 
element ;  r,  Dermal  rays  ;  s, 
Dermal  spine  forming  an- 
terior border  of  ün  (after 
.Smith  Woodward). 


Fig.  38. 

Acanthodes  gradlis,  Beyr.    Scales  from  the  outer  {A,  C)  and 
inner  (J5)  aspects,  much  enlarged.     Lower  Permian  ;  Germany.  j 


H.    and   A.,   from   Goal 


22 


PISCES 


CLASS I 


Family  2.     Diplacanthidae.     Smith  Woodward. 

Two  dorsal  fins.  Free  spines  hetween  paired  fins  conspiciious.  Upper  Silurian 
to  Upper  Devonian. 

Diplacanthus,  Ag.  (BhadinacantJms,  Traquair).  Trunk  fusiform,  probably 
not  much  laterally  compressed.  Teeth  minute  or  absent ;  orbit  with  ring  of 
four  circumorbital  plates.  Pectoral  fins  large,  and  a  median  pair  of  stout 
spines  fixed  between  these  to  the  well-developed  basal  Supports ;  a  single  pair 
of  free  spines  between  the  pectoral  and  pelvic  fins.  D.  striatus,  Ag.,  about 
0*1  m.  in  length,  and  other  species  from  the  Lower  Old  Red  Sandstone  of 
Scotland.  D.  horridus,  Smith  Woodward,  from  Upper  Devonian,  Scaumenac 
Bay,  Canada. 

Ischnacanthus,  Powrie  (läinocephalus,  Page).  Much  resembling  Diplacanthus, 
but  the  inner  pectoral  spines  wanting,  and  the  jaws  provided  with  a  powerful 
dentition.  A  few  large,  smooth,  conical  teeth  alternating  with  minute  cusps. 
Scales  smooth.  /.  gracilis,  Egert.  sp.,  from  Lower  Old  Red  Sandstone,  Turin 
Hill,  Forfarshire. 

Climatius,  Ag.  (Brachyacanthus,  Egert.),  (Fig.  39).  Trunk  fusiform  and 
laterally  compressed.  Teeth  minute  or  absent ;  orbit  with  ring  of  four 
circumorbital  plates.     Fin  spines  remarkably  broad  and  marked  with  coarse 

longitudinal  ridges, 
sometimes  with  posterior 
denticles.  Pectoral  fins 
not  much  larger  than 
the  pelvic  pair;  three 
or  four  pairs  of  free 
spines,  resembling  the 
fin  spines,  between  the 
paired  fins.  C.  reticu- 
latus,  Ag.,  and  C.  seidiger, 
Egert.  (Fig.  39),  are 
known  by  nearly  complete  fishes  from  the  Lower  Old  Red  Sandstone  of 
Forfarshire.  Similar  spines  occur  in  the  Passage  Beds  (Downtonian)  of  Here- 
fordshire,  and  in  the  Lower  Devonian  of  Campbellton,  New  Brunswick. 

EiUhacanthus,  Powrie.  Essentially  identical  with  Climatius,  but  with 
narrower  straight  spines.     Lower  Old  Red  Sandstone,  Forfarshire. 

Parexus,  Ag.  Much  resembling  Climatius,  but  the  anterior  dorsal  spine 
enormously  elongated  and  with  large  posterior  denticles.  P.  incurvus,  Ag., 
and  P.  falcatus,  Powrie,  from  Lower  Old  Red  Sands  tone,  Forfarshire. 


ClimatUis  scutiger,  Egerton.     Lower  Old  Red  Sandstone 
Nat.  size  (after  Powrie). 


Forfarshire. 


Order  3.     ICHTHYOTOMI.     Cope.i 

(Proselachii,  Döderlein.) 

Erdoskeleion  well  calcißed,  hut  no  memhrane  calcifications.    Pterygoquadrate  arcade 
rnovahly  articulated  with  the  cranium.     No  circumorbital  plates.     Neural  and  haemal 

1  Beyrich,  E.,  Mouatsb.  Berlin  Akad.  1848,  pp.  2^-^Z.—Brongniart,  C,  Bull.  Soc.  Industrie 
Mm.  (Saint  Etienne),  ser.  3,  vol.  II.  livr.  4,  1888.— Co^^e,  K  D.,  Proc.  Amer.  Phil.  Soc.  1884,  p. 
bi2.— Davis,  J.  ir.,  On  the  fossil  Fish-remains  of  the  Goal  Measures  in  the  British  Islands.  I. 
Pleuracanthidae  (Trans.  Roy.  Dublin  Soc.  ser.  2,  vol.  XII.),  X^^"^.— Döderlein,  L.,  Zool.  Anzeig.  vol. 


SUB-CLASS  I 


SELACHII 


23 


arches  of  mrtehral  axis  long  and  slender.  Pedoral  fins  with  long,  segmented  axis 
from  which  smaller  cartilages  diverge  on  either  side  ;  pelvic  jins  of  male  with  appended 
elasper  ;  caudal  fin  diphycercal. 


Family  1.     Pleuracanthidae.     Cope. 

Bodt/  slender,  but  slightly  depressed .;  mouth  terminal.  Teeth  with  two  principal 
divergent  ciisps.  Branchial  arches  provided  with  Clusters  of  minute  denticle's.  Dorsal 
fin  elongate,  low,  continuous  along  the  hack  from  a  point  shortly  hehind  the  head ; 
slender  fin  supports  more  numerous  than  the  neural  spines.  Lower  Carboniferous 
probably  to  Upper  Triassic. 

The  Pleuracanthidae  occur  in  the  coal-bearing  strata  of  the  Carboniferous 
System  and  in  the  Lower  Permian  of  Europe  and  North  America.  One 
species  is  also  known  by  a  nearly  complete  skeleton  from  the  Hawkesbury 
Formation  of  New  South  Wales.  For  the  isolated  teeth  of  Pleuracanthus 
various  generic  names  have  been  proposed,  e.g.  Diplodus,  Ochlodus,  Aganodus, 
Pternodus,  Triodus,  Thrinacodus  ;  for  isolated  spines,  the  generic  names  Compsa- 


FiG,  40. 
Restoration  of  Pleuracanthus  gaudn/i,  Brongn.    Goal  Measures  ;  Comineutry,  Allier  (after  C.  Brongniart). 

canthus,  Orthacanthus,  and  Lophacanthus ;  for  the  clustered  denticles  of  the 
branchial  arches,  the  name  Stemmatias  (Stemmatodvs). 

Pleuracanthus,  Ag.  (Xenacanthus,  Beyrich;  "i  Didymodus,  Cope),  (Figs.  40-43). 
Head  broad,  semicircular  in  front,  and  provided  behind  with  a  long,  slender 
dermal  spine,  which  is  hollow,  either  rounded  in  section  or  antero-posteriorly 
compressed,  and  bears  a  double  longitudinal  series  of  recurved  denticles  (Fig. 
42).  Teeth  (Fig.  43)  with  two  large  divergent  cusps  fixed  on  a  stout  common 
base,  and  frequently  a  small  third  cusp  between  these.  Five  branchial  clefts 
laterally  placed  in  advance  of  the  stout  and  broad,  arched  pectoral  girdle,  of 
which  the  two  halves  are  fused  ventrally  but  separated  dorsally.  Pectoral 
fins  large,  articulated  with  the  postero-inferior  angle  of  the  pectoral  girdle, 
and  consisting  of  a  segmented  axis  fringed  on  either  side  by  cartilaginous  rays. 
Pelvic  Supports  in  the  form  of  a  pair  of  separate  triangulär  cartilages ;  basi- 

11.  1889,  p.  l2Z.—  Fritsch,  A.,  Fauna  der  Gaskohle,  vol.  II.  Prague,  \^^9>-^^.—Goldfuss,  A.,  Neues 
Jahrb.  1847,  p.  404,  and  Beiträge  zur  vorweltlichen  Fauna  des  Steinkohlengebirges,  p.  23,  pl.  v. 
Figs.  9,  10.— Kner,  R.,  Sitzuugsb.  k.  Akad.  Wiss.  Wien,  math.-naturw.  Cl.  vol.  551,  1867,  p.  540, 
with  10  plates. — Koken,  E.,  Sitzungsb.  Ges.  naturf.  Freunde,  Berlin,  1889,  p.  77. 


24 


PISCES 


CLASS I 


pterygium  of  pelvic  fins  segmented,  fringed  on  one  side  with  a  series  of  carti- 
laginous  rays,  and  continued  behind  into  the  spine-shaped  clasper  in  the  male. 
Two  small  anal  fins,  directly  supported  by  the  haemal  arches.      Caudal  fin 


Fig.  42. 

Fleuracanthna^Orthacanthus) 
bohemicus,  Fritsch.  Lower 
Pennian  (Gas  -  Goal)  ;  Krot- 
schow,  Boheinia.  A,  Side 
view.  B,  Hinder  view.  C, 
Transverse  sectioii.  Natural 
size. 


Fig.  41. 

Pleuracanthus  {Xeruijcanthus)  decheni,  Goldf.  Lower  Permian  ;  Biaunau, 
Bohemia.  x  1/2.  A,  Anterior  portion  of  fish.  B,  Detached  teeth,  raagnitted 
(after  F.  Roemer). 


Fig.  43. 

Pleuracanthus (Diplodus)  ho- 
hemicus,  Queiist.  Teeth  in 
side  view  (A),  and  hinder 
view  (B).  Lower  Permian 
(Gas  -  Goal)  ;  Xyfan,  near 
Pilsen,    Bohemia.        Natural 


separated  both  from  the  anals  and  from  the  dorsal.     Skin  probably  destitute 
of  shagreen. 

Complete  skeletons  are  known  from  the  Rothliegenden  of  Lebach,  near 
Saarbrücken,  in  Ehenish  Prussia,  and  of  Braunau  and  Ruppersdopf  in  Bohemia ; 
from  the  Lower  Permian  Gas-Coal  of  Bohemia ;  from  the  Goal  Measures  of 
Commentry  in  France  (Fig.  40) ;  and  from  the  Lower  Hawkesbury  Formation 
of  New  South  Wales.     Complete  skulls  have  been  found  in  the  Goal  Measures 


SUB-CLASS  I 


SELACHII 


25 


of   Northumberland   and   in   the   Permian   of   Texas   (Didymodus).      Isolated 
teeth  and  spines  are  very  abundant  in  the  Carboniferous  and  Permian. 

Anodontacanthus,  Davis.     Dorsal  spines  without  denticles.     Carboniferous; 
England  and  Scotland.  ~~  —   ~ 


Order  4.     PLAGIOSTOMI.     Dum^ril.       Sharks  and  Rays.^ 

Endoskeleton  more  or  less  calcified,  hut  no  membrane  calcificafions.  Pterygo- 
quadrate  arcade  movably  articulated  with  the  cranium.  Vertebral  axis  segmented. 
Paired  fins  with  two  or  three  shorf  basal  cartilages  ;  pelvic  fins  of  male  with  appended 
claspers. 

According  to  the  condition  of  their  vertebral  column,  the  Plagiostomi 
have  been  divided  by  Hasse  into  the  four  sub-orders  of  Diplospondijli,  Cyclo- 
spondyli,  Asferospondyli,  and  Tectospondyli. 


Sub-Order  A.     DIPLOSPONDYLI.     Hasse.. 

Notochord  imperfedly  segmented  by  vertical  partitions.  Gill  clefts  six  or  seven 
in  number  on  each  side.  Teeth  numerous,  in  several  series.  Upper  Jurassic  to 
Recent. 

Family  1.     Notidanidae. 

Body  fusiform,  with  a  single  unarmed  dorsal  and  anal  fin,  and  a  large  hetero- 
cercal  caudal  fin.  Teeth  with  two  or  more  sharply-pointed  cusps.  Upper  Jurassic 
to  Recent. 

Notidanus,  Cuv.  (Hexanchus,  Heptanchus,  Müller  and  Henle),  (Figs.  44,  45). 
Principal  teeth  consisting 
of  a  series  of  compressed 
cusps  fixed  upon  a  long 
base ;  all  the  cusps  in- 
clined  in  one  direction, 
the  anterior  larger  than 
the  others,  with  or  with- 
out small  denticles  at  its 
base  in  front.  Anterior 
teeth  of  the  upper  jaw 
clustered,  awl-shaped ;  a 
median  symphysial  series 
in  the  lower  jaw.  Prin- 
cipal teeth  of  the  upper 
jaw  less  laterally  elon- 
gated,  with  fewer  cusps 
than  those  of  the  lower 
jaw.  Range  from  Upper 
Jurassic  to  present  day. 
N.  muensteri,  Ag.,  repre- 
sented  by  a  complete 
skeleton  from  the  Lithographie  Stone  (Lower  Kimmeridgian)  of  Solenhofen, 

1  Bonaparte,  C.  X.,  Selachorum  tabula  analytica  (Mein.  Soc.  Sei.  Nat.  Neufchatel),  1839.— 
Davis,  J.  W.,  Oll  tlie  Fossil  Fishes  of  the  Carboniferous  Liniestone  Series  of  Great  Britain  (Trans. 
Roy.  Dublin  Soc.  ser.  2,  vol.  I.),  1883.— //asse,  C,  Das  natürliche  System  der  Elasmobranchier  auf 


Fig.  44. 

Dentition  of  the  Recent  Indian  Grey  Shark,  Notidanus  (Heptanchus) 
indicus. 


26 


PISCES 


CLASS  I 


Bavaria,  and  K  gracilis,  Davis,  by  a  smaller  skeleton  from  the  Upper  Cretaceous 
of  Sahel  Alma,  Mount  Lebanon.  Detached  teeth  from 
the  Oxford  Clay  of  England  and  Corallian  of  Würtem- 
berg;  from  the  Chalk  of  England  (N.  microdon,  Ag.) 
and  the  Cretaceous  of  New  Zealand  (N.  dentatus,  Sm. 
Woodw.) ;  and  numerous  species  from  Tertiary  forma- 
tions  (e.g.  N.  primigenius,  Ag.,  Fig.  45). 

Chlamydoselache,  Garman.  Teeth  with  broad,  back- 
wardly  extended  base,  and  the  crown  consisting  of  three 
slender,  curved,  subconical  cusps,  which  are  separated 
by  a  pair  of  rudimentary  denticles.     Wide  distribution 

in  existing  deep  sea.      Isolated  teeth   in   Pliocene   of  Tuscany   (C.  lawleyi, 

Davis). 

Sub-Order  B.     CYCLOSPONDYLI.     Hasse. 

Vertehral  centra  in  form  of  simple  constrided  cijlinders  pierced  hy  the  notochord. 
Teeth  numerous,  triangulär,  and  acuminate,  simple  or  with  small  lateral  cusps.  Eare 
in  the  fossil  state ;  Upper  Cretaceous  to  Recent. 


Fig.  45. 

Notklanns  primigenins,  Ag. 
Lower  tooth.  Oligocene; 
Weinheim,  Hesse  Darmstadt. 
Natural  size. 


Family  1.     Spinacidae.     Müller  and  Henle.     Spiny  dog-fishes. 


Body  fusiform  to  trihedral,  somewhat  depressed.  Mouth  gently  arched ;  snout 
obtuse.  Gill  clefts  small,  lateral ;  spirades  large,  hehind  the  eye.  Pedoral  fins  not 
notched  at  their  origin  and  not  produced  forwards ;  the  two  dorsal  fins  offen  armed 
with  a  spine  ;  anal  fin  absenf.     Upper  Cretaceous  to  Recent. 

Centrophm'us,  Müller  and  Henle  (Fig.  46).  Dorsal  fin  spines  present. 
Upper  teeth  erect,  triangulär,  or  narrow  lanceolate,  with  a  single  cusp ;  lower 

teeth  triangulär 
and  compressed, 
with  the  apex 
much  turned  aside. 
Upper  Cretaceous, 
Sahel  Alma,  Mount 
Lebanon      (Spinax 


Fig.  4Ö. 

Vertebra  (central  double-cone) 
of  Cenfrophorus.  Upper  Cre- 
taceous ;  Maastricht  (after 
Hasse). . 


Fig.  47. 

Acanthi(ts  radicaim, 
Probst.  Tooth,  x  2. 
Miocene  (Molasse) ; 
Baltringen,  Würteni- 
berg  (after  Probst.) 


Fig.  48. 


Scymnus  triangulus, 
Probst.      Tooth,  x  2.  .  -r»-    i.    i.\ 

Miocene       (Molasse);  pnmaeVUS,     riCtet;. 

Baltringen     (after  T>f,f.f,j.f 

Probst.)  xieceni. 


Äcanthias,  Risso 

(Centrophoroides,  Davis),  (Fig.  47).  As  Centrophorus,  but  teeth  in  upper  jaw 
as  in  lower  jaw.  Upper  Cretaceous,  Sahel  Alma,  Mount  Lebanon  {Centro- 
phoroides  latidens,  Davis).     Tertiary  {A.  radicans,  Probst)  and  Recent. 

Centrina,  Cuv.     Pliocene  and  Recent. 

Scymnus,  Cuv.  (Fig.  48).  No  dorsal  fin  spines.  Upper  teeth  small, 
pointed ;  lower  teeth  much  larger,  broad  and  compressed,  triangulär,  erect  or 
only  slightly  inclined  laterally.     Eocene  to  Recent. 

Echinorhinus,  Blainv.  {Goniodus,  Ag.)     Pliocene  and  Recent. 

Grundlage  des  Baiies  und  der  Entwickelung  ihrer  Wirbelsäule.  Jena,  1879,  with  Appendix,  1885. 
— Malier,  J.,  and  Henle,  J.,  Systematische  Beschreibung  der  Plagiostomen.  Berlin,  1841. — Jaekel, 
0.,  Die  eoeänen  Selachier  vom  Monte  Bolca.  Berlin,  1894. — Noetling,  F.,  Die  Fauna  des  samläii- 
dischen  Tertiärs  (Abhandl.  geol.  Specialk.  Preussen,  vol.  VI.  pt.  3),  1885.— iVoös^,  Beiträge  zur 
Kenntniss  der  fossilen  Fische  aus  der  Molasse  von  Baltringen  (Württemb.  naturw.  Jahresh.),  1874. 
1877,  1878,  and  1882. 


SUB-CLASS  I 


SELACHIl 


27 


Sub-Order  C.     ASTEROSPONDYLI.     Hasse, 


Vertehral  centra  when  completely  formed  amphicoelous,  strengthened  hy  secondary 
plates  of  calcißed   tissue  which  radiale  outwards  from   the   excessively  constricied 
cylinder.     Five  gilt  clefts  on  each  side.     Two  dorsal  fins  and  one  anal  fin 
Lower  Carboniferous  to  Recent. 


Fi(i.  4it. 

Orodxts  ramosus,  Ag.   Carboniferous  Limestone  ; 
Arinagh  (after  Davis).    1/2. 


Family  1.     Oestraciontidae.     Agassiz. 

Dorsal  fins  each  armed  with  a  spine.  Teeth  numerous,  mostly  obtuse,  never  fused 
into  continuous  plates  ;  several  series  simultaneously  in  funäion.  Radiating  plates  of 
the  vertehral  centra  few  and  short ;  vertehral  column  not  calcified  in  the  earlier  forms. 
Lower  Carboniferous  to  Recent. 

1^         This  family  is  characteristic  of    the  later   Palaeozoic  and  the    Mesozoic 

formations ;    it    is    represented    in    existing    seas    solely    by    one    genus, 

Cestracion. 

Orodus,  Ag.  (Fig.  49),  kno wn  only  by  obtuse  elongated  teeth.     The  dental 

crown  raised  in  the  middle,  and  its  surface  marked  with  more  or  less  prominent 

wrinkles,  which  rise  from  each  long  margin 

or  from  a  median  longitudinal  crest.     Base 

of  tooth  very  stout.     0.  ramosus,  Ag.  (Fig. 

49),  and  other  species  from  the  Carboniferous 

Limestone  of  Britain,  Belgium,  and  Russia. 

Also    numerous    species    in    corresponding 
American  formations. 

Campodus,  Kon.  (Agas- 
sizodus,  St.  J.  and  W. ;  Arpagodus,  Traut.).  Teeth  almost 
identical  with  Orodus,  but  distinguished  by  buttressed 
condition  of  the  outer  border  of  the  crown.  Symphysial 
series  greatly  enlarged,  and  fused.  Carboniferous.  Edestus, 
Leidy  ;  Campyloprion,  Eastm.  ;  and  Helicoprion,  Karp., 
known  only  by  their  arched  or  coiled  symphysial  dentition. 
Carboniferous  and  Permian. 

Tristychius,  Ag.  (Ptychacanthus,  Ag.),  (Fig.  50).  Dorsal 
fin  spines  with  a  few  sha^-D  longitudinal  ridges  distally, 
three  only — one  upon  the  front  margin  and  one  on  each 
side — extending  far  downwards.  Teeth  probably  as  in 
Sphenacanthus.     T.  arcuatus,  Ag.     Carboniferous. 

Sphenacanthus,  Ag.  Töeth  rather  high-crowned,  with  a 
large  principal  cusp  and  smaller  lateral  cusps  diminishing 
in  size  outwards,  more  or  less  marked  by  superficial 
wrinkles ;  base  depressed,  forming  a  slight  expansion  back- 
wards.      Notochord   persistent.     Dorsal   fin   spines  marked 

Ag^BZfedün.rh!f(Ä)    ^^*^  robust  lougitudinal  ridges,  in  part  nodose ;  posterior 

shagreen-scaie  (B),  and   denticles  small  and  numerous,  in  two  series,  one  upon  each 

si?e.     Lower"ca?boS!   lateral  margin  of  the  flattened  or  slightly  concave  posterior 

stTck).'  ^"""^^^"'^  ^^^^'''  face.       Few   minute    comb-shaped   shagreen   granules.      S. 
costellatus,    Traquair   sp.,    known    by    nearly   complete    fish 

from  Calciferous   Sandstones   (Lower  Carboniferous)   of   Eskdale,    Dumfries. 


Fig.  50. 


PISCES 


CLASS  I 


^^f 


^ßl^ 


Fig.  51. 


S.  hybodoideSf   Egert.   sp.,   represented   by   fin   spines   and   teeth    in  English, 

Welsh,  and  Scottish  Goal  Measures. 

Hybodus,  Ag.  (Meristodon,  Ag.),  (Fig.    51).     Teeth  and  dorsal  fin  spines 

almost  as  in  Sphenacanthus  ;  but  double  series  of  denticles  on  hinder  face  of 

fin-spine  median,  not  laterally  placed. 
Symphysial  teeth  few  and  relatively 
large.  Notochord  persistent,  but  ver- 
tebral  arches  calcified.  One  or  two 
large  hook-shaped,  semi-barbed  dermal 
spines  (Sphenonchus)  immediately  behind 
each  orbit,  at  least  in  the  male.  Shagreen 
sparse,  consisting  of  small  conical, 
radiately  grooved  tubercles,  which  are 
sometimes   fused  into  groups   of    three. 

Numerous  species  ranging  from  the  Trias  to  the  Lower  Cretaceous.     Teeth 

of  H.  plicatiUs,  Ag.  (Fig.   51,  A),  abundant   in   the   Muschelkalk.      Nearly 

complete  skeletons  from  the  Lower  Lias  of  England  (H.  delabechei,  Charles- 

worth ;  H.  reticulatus,  Ag.,  Fig.  51,  ^)  and  the  Upper  Lias  of  Würtemberg  (H. 

hauffianuSj  Eb.  Fraas).      Fine    skulls  from  Wealden,  Pevensey  Bay,  Sussex 

{R.  basanuSf  Egert.). 

Acrodus,  Ag.  (Thedodus,  Plieninger),  (Fig.    52).     A  genus  only  differing 

from  Hybodus  in  the  rounded,  non-cuspidate  character  of  the  teeth.     Common 


Teeth  ofif//öodws.  A,  H.  plicatiUs,  Ag.  Muschel- 
kalk ;  Laineck,  iiear  Bayreuth.  B,  H.  reticulatus, 
Ag.  Lower  Lias  ;  Lyme  Regis,  Dorsetshire.  C,  H. 
polyprion,  Ag.  Lower  Oolite  (Dogger) ;  Stonesfield, 
Oxfordshire. 


Fio.  52. 

Acrodus  anningiae,  Ag.     Dentition,  1/3  natural  size.     Lower  Lias  ;  Lyme  Regi 
A,  Symphysis.    B,  Detached  tooth,  seen  from  side  and  above,  natural  size. 


in  the  Triassic  and  Jurassic,  and  ranging  to  the  Upper  Cretaceous.  A. 
gaillardoti,  Ag.,  teeth  from  Bunter,  Muschelkalk,  and  Keuper  of  Germany 
and  France.  A.  minimus,  Ag.,  common  in  European  Keuper  and  Rhaetic. 
A.  anningiae,  Ag.  (Fig.  52),  and  A.  nobilis,  Ag.,  known  by  fine  specimens  from 
the  Lower  Lias,  Lyme  Regis.  A.  levis,  Sm.  Woodw.,  teeth  from  English 
Gault. 

Palaeobates,  Meyer.  Teeth  depressed,  rounded,  without  lateral  denticles 
and  not  keeled.     European  Triassic. 

Asteracanthus,  Ag.  (Strophodus,  Ag.;  Curtodus,  Sauvage),  (Figs.  53,  54). 
Principal  teeth  elongated,  irregularly  quadrate,  with  slightly  arched  but 
flattened  crown ;  symphysial  teeth  few,  smaller  but  relatively   large,  much 


SU15-CLASS  I 


SELACHII 


29 


arched,  without  lateral  denticles,  and  longitudinally  keeled  ;  all  superfi 

marked  by  reticulating  ridges.      Notochord  persistent.     Head  spines 

Hyhodus  and  Acrodus.    Dorsal  fin  spines  marked 

by  stellate   tubercles,  sometimes  partly  fused 

into  longitudinal  ribs ;  also  bearing  a  median 

longitudinal  double  series  of  tubercles  on  their 

hinder  face.     Middle  and  Upper  Jurassic.     A. 

ornatissimiis,    Ag.    (Strophodus   reticulatus,   Ag.), 

(Fig.  54),  well  known  from  Corallian,  Oxfordian, 

and  Kimmeridgian  of  Europe. 

Palaeospinax,  Egerton.  Dentition  compara- 
tively  specialised  ;  the  few  anterior  teeth  high- 
crowned  and  prehensile,  with  a  single  pair  of 
lateral  denticles;  posterior  teeth  low-crowned, 
with  two  or  three  pairs  of  lateral  denticles 
reduced  to  minute  beads.  Yertebrae  very 
slightly  asterospondylic.  Dorsal  fin  spines 
smooth  and  enamelled,  without  posterior 
denticles.  Shagreen  fine  and  dense;  no  head 
spines.  P.  priscus,  Egert.,  known  by  nearly 
complete  specimens  from  Lower  Lias,  Lyme 
Eegis.  Fragments  of  other  species  from  Upper 
Lias,  Würtemberg. 


cially 
as  in 


Fig.  54. 

Tootli  of  Asterucanthns  (Strophodus  reticulatus, 
Ag.),  inside  view  aud  upper  view.  Corallian  ; 
Tonnere,  Yoiiiie. 


Fig.  53. 

Asteracanthus  ornatissimus,  Ag.  Doixal 
fin-spine,  lateral  view  (A),  posterior  view 
(jB),  aiul  detached  tubercle  eularged  (('). 
Portlandiau  ;  Solenre,  Switzerlaiid. 


Synechodus,  Smith  Wood  ward  (Fig.  55).  Almost  identical  with  Palaeo- 
spinax, but  teeth  with  more  numerous  lateral  denticles,  and  vertebrae  more 
distinctly  asterospondylic.  Complete  jaw  of  S.  duhrisiensis,  Mackie  sp.  (Fig. 
55),  and  greater  part  of  skeleton  of  same  species  known  from  the  Lower 
Chalk  of  England.  Teeth  of  other  species  from  various  Cretaceous  formations 
in  Europe,  Cretaceo-Tertiary  of  New  Zealand  and  Patagonia,  and  one  (S.  clarki, 
Eastman)  from  the  Maryland  Eocene. 

Cestracion,  Cuv.  (Heterodontus,  Blainv.;  Drepanephorus,  Egert.),  (Figs.  56, 
57).  Symphysial  teeth  small,  numerous  and  prehensile,  with  a  median  cusp 
and  one  pair  of  lateral  denticles;  lateral  teeth  in  oblique  series,  with  faintly 
keeled   and   fiiiely   rugose    crown.      Vertebrae    asterospondylic.      Dorsal   fin 


SUB-CLASS  I 


SELACHII 


31 


spines  smooth,  without  posterior  denticles. 
the  Lithographie  Stone  (Upper 
Jurassic)  of  Bavaria  (C.  falcifer, 
Wagn.,  Fig.  56)  and  the  Chalk 
of  England  (so-called  Drepane- 
phorus  canaliculatus,  Egert.). 
Teeth  from  Lower  and  Middle 
Eocene  of  England  and  Belgium. 
Existing  in  Australian  and  other 
seas. 


Family  2.      Scylliidae.     Müller 
and  Henle. 

Dorsal  fins  without  spines,  the 
anterior  situated  above  or  behind  the 
pelvic  fins.  Teeth  small,  numeivus, 
and  pointed,  several  series  being 
generally  in  function.  Vertebrae 
with  eight  stout  radiating  plates. 
Upper  Jurassic  to  Eecent,  but 
fossils  rare. 


Nearly  complete  skeletons  from 


Fig.  57. 

Lower  jaw  of  Recent  Port  Jackson  Shark,  Cestracion  'pMUppi, 
Cuv.     Australia. 


Fig.  58. 

Scyllium  dislans, 
Probst.  Tooth,  x  2. 
Miocene    (Molasse) ; 


Palaeoscyllium,  Wagn.  Anterior  dorsal  fin  opposite  pelvic  pair,  and 
posterior  dorsal  arising  in  advance  of  anal,  which  is  small.  P.  formosum, 
Wagn.,  and  P.  minus,  Sm.  Woodw.,  known  by  nearly  complete  fishes  from 
Lithographie  Stone,  Bavaria. 

Scyllium,  Cuv.  (Tht/ellina,   Ag.),   (Fig.    58).     Origin  of  anal  fin  always  in 

advance  of  that  of  posterior  dorsal  fin.     Teeth  delicate  with  a  high  middle 

cusp  and  generally  one  or  two  small  lateral  denticles.     Xearly 

(^  complete  fishes  from  the  Upper  Cretaeeous  of  Westphalia  (S. 

jÄlq  ^ßU        angustum,  Ag.  sp.)  and  Mount  Lebanon  (S.  elongatum,  Davis 

||||r  Wm       sp.) ;    also    numerous    detached    teeth    from    the    Chalk   and 

Tertiaries  (Fig.  58).     Recent. 

Pristiurus,  Bonap.  As  Scyllium,  but  with  a  series  of  small 
flat  spines  on  eaeh  side  of  the  upper  edge  of  the  caudal  fin. 
ProbstS"^*^"^*^^^^  ^'  ^(^^^^h  Sm.  Woodw.,  a  small  species  from  the  Lithographie 
Stone  of  Eichstädt,  Bavaria.  Eecent. 
Mesiteia,  Kramberger.  Snout  produced.  Teeth  minute  and  tricuspid. 
Anterior  dorsal  fin  above  or  behind  pelvic  pair ;  anal  fin  much  extended. 
Tail  excessively  elongated,  without  dermal  scutes  or  spines.  Shagreen  absent 
or  very  delicate,  and  lateral  line  supported  by  a  series  of  calcified  rings  as  in 
Chimaeroids.  M.  emiliae,  Kramberger,  from  Upper  Eocene,  Monte  Bolca, 
near  Verona ;  M.  sahel-almae,  Pict.  and  Humb.  sp.,  from  Upper  Cretaeeous, 
Mount  Lebanon. 

Chiloscyllium,  Müll,  and  Henle,  and  Ginglymo Stoma,  Müll,  and  Henle 
{Plicodus,  Winkler ;  Acrodobatis,  Leidy).     Tertiary  and  Recent. 

Family  3.     Oarchariidae.     Müller  and  Henle. 

Dorsal  fins  without  spines,  the  anterior  situated  opposite  to  the  space  between  the 
pectoral  and  pelvic  fins.     Teeth  hollow,  pointed  and  triangulär,   with  smooth  or 


32 


PISCES 


CLASS I 


serrated  lateral  hm'ders,      Vertehral  cerdra  with  four  radiating  ridges  which  widen 
outwards.     Tertiary  and  Recent. 

Hemipristis,  Ag.  (JDirrhizodon,  Klunzinger),  (Fig.  59).  Principal  teeth 
large,  triangulär  and  compressed,  with  coarsely  serrated  edges ;  anterior 
lower  teeth  slender,  subulate,  inwardly  curved,  and  without  denticulations  or 
with  one  or  two  minute  points  at  the  base.  H.  serra,  Ag.  (Fig.  59),  common 
in  the  Miocene  of  Europe  and  in  the  Tertiary  Phosphate  Beds  of  South 
Carolina  and  Maryland  Miocene.  H.  ciirvatus,  Dames,  from  Oligocene,  Birket- 
el-Qurün,  Egypt.     One  existing  species. 

Galeocerdo,  Müller  and  Henle  (Fig.  60).  Teeth  oblique,  serrated  on  both 
margins,  with  a  deep  notch  posteriorly.     Eocene  to  Recent.     G.  latidens,  Ag., 


J'io.  59. 

Hemipristis  serni,  Ag. 
Neudörtt,  Hungarj'. 


Miocene ; 


Fig.  60. 

A,  Tooth  of  Galeocerdo  aduncus,  Ag. 
Miocene  (Molasse) ;  PfuUendorf,  Baden. 
B,  Section  of  vertebra  of  Galeocerdo. 
Miocene  (Molasse) ;  Baltringen  (after 
Hasse). 


m9b 


Fig.  61. 


Galeus  aßnis,  Probst. 
Miocene  (Molasse) ;  Bal- 
tringen (after  Probst.). 


from  Bracklesham  Beds  and  Maryland  Miocene. 
species,  apparently  ranging   to  the   Pliocene. 
triqueter,  East.,  from  the  American  Miocene. 

Alopiopsis,  Lioy,  and  Fsevdogaleus,  Jaekel. 
Upper  Eocene,  Monte  Bolca,  near  Verona. 

Galeus,  Ag.  (Protogaleus,  Molin.),  (Fig.  61). 


G.  aduncus,  Ag.  (Fig.  60,  ^), 
G.   contortus,  Gibbes,  and  G. 

Nearly  complete  fishes  from 


J^  Ä  <wbi 


Fig.  62. 


Teeth  small  and  oblique,  the 
margins  only  serrated  at  the 
base,  and  a  deep  notch  pos- 
teriorly.    Eocene  to  Recent. 

Carcharias,  Cuv.  (Fig.  62). 
Teeth  mostly  oblique  and  tri- 
angulär, without  lateral  denticles, 
usually  difFerent  in  the  two  jaws. 

A,    Carcharias    (Aprionodon)  frequens,    Dames.       Eocene;  The  lateral      edgCS     SCrratcd     tO 

Birket-el-Qurun,  Egypt  (after  Dames).     B,  Carcharias  (Hypo-  .v^  „^^,,        /  D  .'^      ^             at-ii 

pHon)  singiUans,  Probst.      C,  Carcharias  (Scoliodon)  kraussi,  ^üe  apex        {Fnonodon,       Mullcr 

Probst.    D,  Carcharias  (Prionodon)  similis,  Probst.     Miocene  onH  TTpnlp\    nv    c\W\\t  af  f>io    Kqoo 

(Molasse) ;  Baltringen  (after  Probst.).  '^"^  Xienie;    or    Oniy  at  tüe    Dase 

{Hypoprion,  M.  and  H.),  or  sharp- 
edged  but  not  serrated  {Scoliodon,  Physodon,  M.  and  H.),  sometimes  also  erect 
and  sharp-edged  {Aprionodon,  Gill).     Tertiary  and  Recent. 

Sphyrna,  Raf.  {Zygaena,  Cuv.).  Hammerhead  sharks.  Tertiary  and  Recent. 
S.  prisca,  Ag. 

Mustelus,  Cuv. ;  Triaenodon,  Triacis,  M.  and  H.     Recent. 


Family  4.     Lamnidae.     Müller  and  Henle. 

Dorsal  fins  without  spines,  the  anterior  situated  opposite  to  the  space  bettveen  the 
pectoral  and  pelvic  fins.     Teeth  pointed  and  usually  large,  with  or  tuithout  lateral 


8ÜJ5-CLASS  I 


SELACHII 


33 


i 


Fig.  63. 
Orthacodus  longidens, 


denticles,  and  the  pidp  cavity  completely  filled  with  vasodentine.      Vertebral  centra 
with  eight  bifurcafing  pJates  which  radiate  oufwards.     Upper  Jurassic  to  Recent. 

Orthacodus^  Sm.  Woodw.  (Sphenodus,  Ag.,  non  Gray,  nee  Lund),  (Fig.  63). 
Teeth   very  slender  and   erect,   compressed,   without   lateral 
denticles  ;  the  root  broad  and  depressed,  simple.      0.  longidens, 
Ag.    sp.    (Fig.    63),   and   other   species   are   Upper   Jurassic. 
Apparently  also  a  Lower  Cretaceous  genus. 

Scapanorhynchus,  Sm.  Woodw.  (Bhinognathus,  Davis  nA)n 
Fairmaire ;  ?  Mitsukurina,  Jordan).  Body  slender,  snout 
much   elongated.      Second    dorsal    fin    small,   opposed  to  a 

much  extended  anal  fin ;  caudal 
fin  much  elongated,  inferiorly 
notched  near  the  extremity.  Teeth 
as  in  Odontaspis.  ^  Complete  ^§1^,^!;^^^' 
skeletons  of  S.  lewisi,  Davis  sp., 
and  S.  elongatus,  Sm.  Woodw.,  from  the  Upper  Cre- 
taceous of  Sahel  Alma,  Mount  Lebanon.  Detached 
teeth  (S.  rhaphiodon,  Ag.  sp.)  in  Upper  Cretaceous 
of  Europe,  probably  also  in  North  America,  India, 
and  New  Zealand.  Apparently  living  in  the  deep 
sea  off  Japan  (Mitsukurina  owstoni,  Jordan). 

Odontaspis,  Ag.  (Triglochis,  M.  and  H. ;  Otodus, 
Ag.  in  part.),  (Fig.  64).  Snout  not  much  elongated. 
Second  dorsal  fin  and  the  anal  of  equal  size,  scarcely 
smaller  than  the  first  dorsal.  Side  of  tail  without 
keel.  Teeth  with  a  slender  principal  cusp,  with 
sharp  lateral  edges,  flattened  outer  face,  and  convex  inner  face,  also  one  or 
two  pairs   of   small    lateral   denticles ;    root  large   and    bifurcated.      Upper 


Fig.  64. 

Odontaspis  mspidata,  Ag.  sp. 
Oligocene  ;  Weinheim,  near  Alzey. 


Vertebra  of  Lamna,  ili  front  (.4)  and  side  view  (B),  and  in  vertical  median  section  (6%    Nat.  size. 
A,  B,  From  Oligocene  of  Flonheim.     C,  From  London  Clay,  Sheppey. 


Cretaceous,  Tertiary  and  Recent.  0.  hronni,  Ag.  U.  Cretaceous,  Maastricht 
and  Ciply.  0.  elegans,  Ag.  sp.,  and  0.  cuspidata,  Ag.  sp.  (Fig.  64),  from 
Lower  Tertiaries. 

Otodus,  Ag.  (Figs.  65-67).     Very  robust  teeth  with  stout  lateral  denticles, 

VOL.  II  D 


34 


PISCES 


CLASS I 


of  rather  doubtful  relationships.     Most    species  describecl   under   this   name 
referable  to  Lamna  and  Odontaspis.     Cretaceous  and  Eocene. 

Lamna,  Cuv.  Second  dorsal  fin  and  the  anal  very  small.  Side  of  tail  with 
keel.  Teeth  as  in  Odontaspis,  but  the  principal  cusp  usually  somewhat  broader 
and  the  lateral  denticles 
larger.  Very  abundant 
in  the  Chalk,  Tertiaries, 
and  existing  seas. 

OxyrJiina,     Ag.     (Fig. 
68).     Only  difFering  from 


F](i.  üü. 
Otodus  appendü'u- 
latus,  Ag.  Pläner; 
Quedlinburg. 


Fig.  ()7. 
Otodiis     obliqmis,     Ag.       Extenial 
aspect  of  tooth.     Eocene  ;  Sheppey. 


Fig.  68. 

(hi/rhinaplicatilis,  Ag.  Mio- 
cene';  Neudörfl,  Hungary. 


Lamrut  in  the  teeth  lacking  lateral  denticles.  Cretaceous  to  Recent.  0. 
mantelli,  Ag.,  the  commonest  Cretaceous  species  both  in  Europe  and  North 
America,  the  nearly  complete  dentition  known  from  Kansas.  0.  desori,  Ag., 
chiefly  Lower  Tertiary  ;  0.  hastalis,  Ag., 
chiefly  Upper  Tertiary. 

Alopecias,  M.  and  H.     Tertiary  and 
Recent. 

Coi-ax,  Ag.  (Fig.  69).     Known  only  ^^bh^  -^ 

by    low    triangulär    teeth    with    sharp,  JHHI\-  "'^ 

serrated  edges,  and  a  large  root.  Com- 
mon in  the  Middle  and  Upper  Cre- 
taceous. C.  pristodordus,  Ag.,  from 
Maastricht,  North  Africa  (Fig.  69),  and 


('onu:  jyistodoutHs,  Ag. 
Upper  Chalk ;  Oasis  of 
Dacliel,  Libyan  Desert. 


'aicharodonmegalodo)i,Ag.     Miocene ;  Malta. 


supposed  Eocene  of  Alabama.      C.falcatus,  Ag.,  European  and  North  American 
Cretaceous. 

Carcharodon,  M.  and  H.  (Fig.  70).  Second  dorsal  fin  and  the  anal  very 
small.  Side  of  tail  with  keel.  Teeth  very  large  and  triangulär,  with 
serrated  lateral  edges,  flattened  outer  face,  convex  inner  face.     One  Upper 


SUB-CLASS  I 


SELACHII 


35 


Cretaceous  (C  loagidens,  Pillet)  and  one  existing  species  (C.  mndeleti,  M.  and 
H.) ;  the  others  Tertiary.  C.  megalodon,  Ag.  (Fig.  70),  and  allied  species  are 
represented  by  very  large  teeth  in  the  Tertiary  and  later  formations  of 
nearly  all  parts  of  the  world,  also  on  the  bed  of  the  existing  oceans.    " 

Cetorhinus,  Blv.  (Selache,  Cuv.).  Teeth  very  small  and  conical,  without 
lateral  denticles.  Claspers  of  male  with  horn-shaped  spines,  which  have 
been  found  in  the  Pliocene  of  England  and  Belgium.  The  existing  "  basking 
shark." 

Sub-Order  D.     TECTOSPONDYLI.     Hasse. 

Vertebral  centra  when  comyletely  formed  ainphicoelous,  strengthened  hy  secondary 
plates  of  calcified  tissue  which  are  concentric  with  the  constriäed  primitive  cylinder. 
Five  gill  clefts  on  each  side.  Anal  fin  absent.  Body  usually  depressed,  with  very 
large  pectoral  fins  forming  a  "  disk." 

To  the  Tectospondyli  belong  the  still  existing  rays,  monk-fishes,  and  saw- 
fishes,  perhaps  also  the  Palaeozoic  families  of  Cochliodontidae,  Psammo- 
dontidae,  and  Petalodontidae. 


Family  1.     Cochliodontidae.     Owen. 

Palaeozoic  fishes  with  few  convex  teeth,  which  are  more  or  less  arched,  hollowed  at 
the  base,  punctate  on  the  crown,  and  offen  marJced  with  obtuse  transverse  folds  or 
grooves.  A  large  posterior  dental  plate,  above  and  below  on  each  side,  a  smaller 
(Uiterior  dental  plate,  and  one  or  more  series  of  separate  smaller  anterior  teeth. 
llead  and  perhaps  also  the  pectoral  fins  armed  with  paired  tuberculated  spines. 
Carboniferous  and  Permian. 

Our  knowledge  of  this  most  remarkable  Upper  Palaeozoic  family  is  still 
very  incomplete.  Of  two  genera  (Helodus  and  Menaspis)  the  Impression  of  the 
trunk  is  known ;  of  all  the  others  only  teeth  or  fin  spines  and,  very  rarely, 
complete  jaws  occur.  According  to  Jaekel  we  may  place  here  the  un- 
symmetrical  Ichthyodorulites,  with  tubercles,  bosses,  or  spines  and  destitute  of 
a  root,  which  have  been  described  under  the  names  of  Oracanthus,  Pnigeacanthus, 
öladacanthus,  Platyacanthus,  Gamps- 
acanthus,  Physonemus,  Stichacanthus, 
etc.  Owen  has  pointed  out  that  the 
deiitition  in  the  typical  genera 
(Jochliodus  and  Streblodus  corresponds 
with  that  of  a  Cestraciont,  but  differs 
from  the  latter  in  the  fusion  of  two 
or  more  transverse  series  of  teeth  into 
continuous  plates.  Smith  Wood  ward 
has  thus  proposed  to  place  the  typical 
Cochliodontidae  near  the  Cestraci- 
ontidae,  removing  Menaspis  *to  the 
Chimaeroid  family  of  Squaloraiidae. 

Cochliodm,   Ag.    (Fig.    71).      Two 
strongly  arched  dental  plates  on  each 

ramus  of  the  mandible ;  the  posterior  one  very  large,  with  a  broad  median 
area  bounded  in  front  and  behind  by  an  oblique  transverse  furrow;  the 
antei-ior  plate  comparatively  small,  rhomboidal  in  shape.     Symphysial  series 


Fk;.  71. 

Cochliodas  contortus,  Aj?.  Dentition,  -Vi  .nat.  size. 
Carboniferous  Limestone  ;  Arniagh.  A,  Large  i)0.sterior 
tooth.     B,  Middle  tooth  ;  anterior  teeth  wanting. 


36  PISCES  CLASS I 

of.C.  latus,  Leidy,  from  Keokuk  Limestone  of  Mississippi  Valley,  the  largest 
known  species,  originally  described  as  Helodus  coxanus,  Newb.  Lower  Carboni- 
ferous ;  Ireland,  England,  Belgium,  and  North  America, 

Streblodus,  Ag.  As  Cochliodus,  but  hinder  tooth  with  two  to  three  broad, 
oblique,  transverse  folds.  S.  oblongus,  Ag.,  and  *S^.  colei,  Davis,  from  Carboni- 
ferous  Limestone,  Armagh.     Other  species  from  England  and  North  America. 

Sandalodus,  Newberry  and  Worthen  (Trigonodus,  Faticinodus,  N.  and  W. ; 
Orthopleurodus,  St.  John  and  Worthen).  Supposed  upper  teeth  triangulär, 
thick,  slightly  inrolled.  Supposed  lower  teeth  more  strongly  inrolled ;  the 
hinder  one  subtriangular  or  twisted  and  elongate,  with  one  to  two  diagonal 
ridges,  and  anteriorly  coiled  in  a  distinct  whorl ;  the  anterior  one  short, 
truncated  in  front,  strongly  inrolled.  Carboniferous ;  Ireland,  England, 
Belgium,  and  North  America. 

Deltoptijchius,  Ag. ;  Chitonodus,  St.  John  and  Worthen ;  Poecilodus,  Ag.  ; 
Deltodus,  Ag.  (Taeniodus,  St.  J.  and  W.) ;  Xystrodus,  Ag.  Carboniferous  Lime- 
stone ;  Europe  and  North  America. 

Psephodus,  Ag.^  (Fig.  72).  Large  rhombic  or  rhomboidal  teeth,  convex 
and    gently   arched,    with    crenulated    border.     With   these    large   teeth  are 


% 


Fig.  72. 

Psephodus  niagmis,  Ag.  A,  Three  teeth  in  connected  series,  nat.  size,  from  the  Carboniferous  Limestone 
of  Armagh  (after  Davis).  B,  Associated  upper  teeth  from  remains  of  head  found  in  Calciferous  öandstones, 
Bast  Kilbride,  Lanarkshire.  b,  Large  tooth  somewhat  broken  ;  c,  Small  tooth  identical  with  Helodus  rudis, 
M'Coy;  d,  ölender  teeth  identical  with  Helodus  planus,  Ag.  ;  e,  Helodont  teeth;  /,  g,  Teeth  identical  with 
Lophodus  didymus  and  L.  Imvissimus,  Ag.  sp.  (after  Traquair).- 

sometimes  associated  more  numerous  transversely  elongated  small  teeth,  of 
which  isolated  examples  have  been  described  under  the  names  of  Helodus, 
Lophodus,  and  Aspidodus.  Carboniferous  Limestone  ;  Europe,  India,  and  North 
America. 

PleuToplax,  Sm.  Woodw.  {Pleurodüs,  Hancock  and  Atthey,  non  Wood,  nee 
Harlan).  Teeth  with  feeble  antero- posterior  ridges,  and  the  antero-  and 
postero- lateral  borders  indented  between  these  ridges.  These  teeth  some- 
times associated  with  others  of  the  Helodus-type.  At  least  one  dorsal  fin,  with 
an  unornamented  spine.  P.  rankinei,  H.  and  A.,  from  English  Coal  Measures. 
Other  species  from  Upper  and  Lower  Carboniferous  of  Europe  and  North 
America. 

Menaspis,  Ewald,   emend.   Jaekel  ^   (Bichelodus,   Giebel ;   Chalcodus,  Zittel), 

^  Traquair,  R.  H.,  Trans.  Geol.  See,  Glasgow,  vol.  VII.  1885,  p.  392. 

2  Jaekel,  0.,  Ueber  Menaspis  (Sitzungsb.  naturf.  Freunde,  Berlin,  1891,  p.  115). — Reis,  0.,  lieber 
die  Koptstacheln  von  Menaspis  armata,  Muuich,  1891. 


SUB-CLÄSS  I 


SELACHII 


37 


(Fig.  73).     Head  and  back  covered  with  longitudinal  series  of  tuberculated  or 

spiny,  partially  keeled   placoid  scales  ^ 

and  small  shagreen  granules.     On  each 

side  of  the  front  portion  of  the  head 

a   triangulär    spine,   provided    with   a 

broad,  hollow  base  and  covered  with 

tubercles    of    dentine.      Further    back 

on  each  side  three  smooth,  thin,  arched 

spines   fixed    by   a  conspicuous    basal 

process  in  the  skin  of  the  head,  curved 

inwards,  and  apparently  consisting  of 

calcified  cartilage  ;  the  middle  pair  of 

these  spines  more  than  twice  as  long 

as  the  others.     Dentition  consisting  of  one  pair  of  Cochliodont  teeth  in  each 

jaw  (Fig;  73).     M.  armata,  Ewald,  from  Kupferschiefer  of  Germany. 


Fig.  73. 


Menaspis    armata, 


Ewald  (Chalcoilus  permiaiius, 
Zittel).  Dentition  froni  above  (A),  and  belovv  (ß),  nat. 
size.     Kupferschiefer ;  Glücksbrunn,  Thuringia. 


Family  2.     Psammodontidae.     De  Koninck. 

Known  only  by  large,  flat,  or  slightly  arched  teeth,  with  punctate  or  finely  rugose 
grinding  surface.  The  teeth  are  of  quadrate  or  oblong  shape, 
and  were  originally  arranged  in  one,  two,  or  more  longitudinal 
series.     Lower  Carboniferous. 

Fsammodus,  Ag.  (Homalodus,  Astrabodus,  Davis), 
(Fig.  74).  Teeth  quadrangular,  with  relatively  thick 
base,  smooth  or  feebly  striated  on  the  attached  surface, 
arranged  in  the  jaw  in  paired  longitudinal  series. 
P.  rugosus,  Ag.  (Fig.  74),  from  Carboniferous  Limestone 
of  Ireland,  Scotland,  England,  Wales,  and  Belgium. 
Allied  species  in  Russia  and  North  America. 

Archaeobatis,  Newberry.  Teeth  scarcely  distinct 
from  Psammodus.  An  associated  group  of  A.  gigas, 
Newb.,  known  from  St.  Louis  Limestone,  Greencastle, 
Indiana  (Ann.  New  York  Acad.  Sei,  vol.  i.  1878,  p.  190). 

Copodus,  Davis  (Mesogomphus,  Bhymodus,  Characodus, 
Pinacodus,  Davis).  Comparatively  small  median  teeth, 
narrower  in  front  than  behind,  divided  into  two  unequal 
parts  by  a  transverse  suture.  C.  cornutus,  Davis,  and 
allied  species  from  Carboniferous  Limestone  of  Ireland, 
England,  and  North  America. 


Fig.  74. 

Psammodus  rugosus,  An. 
Iniperfect  tooth  from  above 
(A),  and  in  transverse  section 
(B),  nat.  size.  Carboniferous 
Limestone  ;  Armagh. 


Family  3.     Petalodontidae.     Newberry  and  Worthen. 

Teeth  anter o-posteriorly  compressed,  transversely  elongated,  arranged  in  longitwliruil 
and  transverse  rows  and  forming  a  pavement.  Crown  enamelled,  more  or  less  bent 
backwaras,  either  with  a  sharp  cutting  edge  or  very  obtuse,  the  anterior  face  convex,  the 
posterior  face  concave  ;  root  separated  from  the  crown  by  a  constriction,  usually  with 
enamel  folds  immediately  above  it.     Carboniferous  and  Permian. 

Of  this  extinct  family,  Janassa  is  the  only  genus  of  which  more  than  the 
dentition  is  known.  This  fish  exhibits  a  ray-shaped  trunk  covered  with 
smooth,  rounded  shagreen  granules ;  the  large  pectoral  fins  extend  forwards 


38 


PISCES 


CLASS I 


to  the  head,  and  the  pelvic  pair  are  separated  froni  them  by  an  interspace  : 
the  tail  is  slender,  and  mouth  narrow.     There  are  no  fin  spines. 

Pefalodus,  Owen  {Chomatodus,  Ag.  in  part ;  Sicarius,  Leidy ;  Antliodns, 
Newb. ;  Lisgodus,  St.  John  and  Worthen),  (Fig. 
75).  Teeth  much  antero-posteriorly  compressed 
and  transversely  elongated.  Crown  leaf-shaped, 
with  cutting  edge  and  sharp  basal  margin  with 
enamel  folds  ;  root  long  and  comparatively  slender, 
truncated  below.  F.  acuminatus,  Ag.  sp.,  and  other 
species  from  the  Carboniferous  Limestone  of  Eng- 
land, Scotland,  Ireland,  Belgium,  Russia,  and 
North  America.  Rare  in  the  Goal  Measures  of 
North  America. 

FefaMiynchus,    Newb.  and   Worth.     Dentition 
Peta.iochis    aiieghnnünsis,    Leidy.   consisting  of  six  transverse  rows  of  three  acumi- 

Tooth  in  front  view  (^)  and  trans-  ,  ,r-  ,       -i  --i  j-     -j    j  i.         ri      i 

verse  section  (ß),  V"  »at.  size.   Goal   nate  cuttmg  teeth  With  unaivided  root.     uarboni- 
SXrryi'^^'""^""^'^' "''"'''' ^''"''  fßi'ous  Limestone  ;  Europe  and  North  America. 

Janassa,  Münster  {Dictaea,  Byzenos,  Münster ; 
Climaxodus,  M'Coy  ;  Feltodus,  Newb. ;  Tanaodus,  St.  John  and  Worthen),  (Fig. 
76).  Dentition  consisting  of  narrow  and  elongated  teeth  with  a  reflexed 
punctate  crown,  which  are  arranged  in  five  to  seven  longitudinal,  and  seven 
transverse  rows,   three  on   either  side  of  the  symphysial  series.       The  oral 


Fig.  7i>. 


Fig.  76. 

Janassa  bituminosa,  Schloth.  sp.     Kupferschiefer;  Glücksbrunn,  Tliuringia.     A,  Upper  and  lower  dentitiou. 

B,  Cross-section,     C,  Tooth  from  in  front,  and  D,  froin  beliind.     E,  Dermal  tubercles,  enlarged. 

cutting  margin  is  formed  entirely  by  the  anterior  face  of  the  crown,  whicli 
is  beut  backwards  sharply  and  overlaps  the  next  older  tooth  in  front, 
which  serves  as  a  support.  The  long,  tapering  root  of  each  tooth  is 
much  compressed  antero-posteriorly,  slightly  arched,  transversely  ridged  on 
the  convex  anterior  face,  smooth  on  the  concave  hinder  face.  Skin  covered 
with  oval  or  quadrate,  smooth,  shagreen  granules.  /.  bituminosa,  Schloth.  sp. 
(Fig.  76),  represented  by  important  specimens  from  the  Kupferschiefer  of 
Hesse  and  Thuringia,  also  from  the  Marl  Slate  of  Durham.     Detached  teeth 


SUB-CLASS  I 


SELACHII 


39 


Fig. 


Callo'prlstodus  pei 
tinatus,  Ag.  sp. 
Measures :  Scotlaiid 


Goal 


of  other  species  (so-called  Clwiaxodus,  etc.)  from  Upper  and  Lower  Carbon i- 
ferous  of  England,  Scotland,  Ireland,  and 
North  America. 

Fissodus,  St.  John  and  Worthen.  Car- 
boniferous  Limestone ;  North  America 
and  Scotland. 

Glossodus,  M'Coy ;  MesolopJiodus,  Sm. 
Woodw.     Carboniferous  Limestone; 

Ireland.  PolyrUlzodus   magnus,   M'Coy.     Tooth   in   froiit 

Polyrhizodus,    M'Coy     (JJactyloduS,    vlew  (^l),  aiul  transverse  section  (i?),  1/2  «at.  slze. 

AT        1    \     /-n-        r-rw\         m      ^1  1        ^         -i.!-  Carboniferous  T.iniestone;  Arinagh(after  M'Coy). 

Newb.),  (Flg.  77).     Teeth  robust,  with  a  &  v  .r/ 

tumid  crown  tapering  to  a  transverse  cutting  edge,  and  the  root  much  sub- 

divided.      P.  magnus,  M'Coy,  and  other  species  from  the  Car- 

**fHH|^         boniferous  Limestone  of 
J^^\  Ireland,  England,  Russia, 

^     _,  and  North  America. 

Vir:     TS 

Ctenopiychius,  Ag. 
(Ctenopetalus,  Harpacodus, 
Petalodopsis,  Davis  ;  Ser- 
ratodus,  de  Koninck.  Teeth  small, 
antero-posteriorly  compressed,  with  sharp 
serrated  edge.  Coal  Measures  and  Car- 
boniferous Limestone ;  England,  Scot- 
land, Ireland,  Belgium,  and  North 
America. 

Callopristodus,  Traquair  (Fig.  78). 
As  Ctenoptychius,  but  root  subdivided. 
C.  peäinatus,  Ag.  sp.,  from  the  Coal 
Measures  of  England  and  Lower  Car- 
boniferous of  Scotland,  also  from  Coal 
Measures  of  Nova  Scotia. 

Peripristis,  St.  John  (Pristodus,  Davis). 
Lower  Carboniferous;  Creat  Britain  and 
U.S.A. 

Family  4.      Squatinidae.     M.  and  H. 
Aiigel-fishes  or  Monk-fishes. 

Trunk  broad  and  depressed.  Pectoral 
fins  large,  separated  hy  a  cleft  from  the 
head,  so  that  the  branchial  openings  are 
still  direded  laterally.  Teeth  pointed  and 
conicol,  without  lateral  dentides.  Two 
dorsal  fins  on  the  tail,  without  spines.  Skin 
covered  with  small  placoid  scales.  Jurassic 
to  Eecent. 

The  Single  genus  Squatina,  Aldro- 
vandi  {PJiina,  Klein  ;  Thaumas,  Münst. ; 
Phorcynis,  Thioll.  ;  Sealdia,  Le  Hon;  Trigonodus,  Winkler),  (Figs.  79-81),  first 
appears  in  the  Upper  Jurassic  and  survives  in  the  existing  fauna.  Complete 
skeletons  of  S.  alifera,  Münst.  sp.  ;  S.  speciosa,  Meyer ;  and  *S^.  acanthoderma, 


Fig.  79. 

Siinatina  alifera,  Münst.  sp.  (  =  Sip(aHna  ncantho- 
(Icrma,  Fraas).  Upper  Jurassic  ;  Eichstädt,  Bavaria. 
(Original  in  Palaeontological  Museum,  Munich.) 


40 


PISCES 


CLASS  I 


Fraas,  occur  in  the  Lithographie  Stone  of  Bavaria  and  AYürtemberg  (Nus- 
plingen) ;  and  the  genus  is  also  represented  in  the  corresponding  formation  of 
Cerin,  Ain,  France.  A  complete  skeleton  of  *S'.  haumbergensis,  von  der  Marck, 
is  known  from  the  Upper  Cretaceous  of  the  Baumberg,  Westphalia  ;  and  more 


•     A  B 


Fjg.  80. 

A,  Squatina  alifera,  Münst.  sp. 
Tooth,  X  2.  Upper  Jurassic 
(Lithographie  Stone) ;  Soleiihofen. 
B,  Squatina  fraasi,  Probst. 
Tootii,  X  2.  Miocene  (Molasse); 
Baltringen. 


•-~C/( 


Fio.  81. 

Longitudinal  section  of  the  tectospon- 
dylic  vertebral  column  of  Squatina 
angelus,  Ijinn.  ch,  Notochord  ;  d,  Cal- 
cified  double-cone  (basis  of  centrum) ; 
iv,  Intervertebral  space  ;  w,  Vertebral 
centra  with  concentric  calcified  rings 
(after  Hasse). 


fragmentary  remains  of  S.  cranei,  Sm.  Woodw.,  occur  in  the  English  Chalk. 
Numerous  teeth  and  vertebrae  in  the  Tertiary.  S.  occidentalis,  East.,  from  the 
Maryland  Miocene. 

Family  5.     Pristiophoridae.     Günther. 

Trunk  fusiform.  Snout  much  elongated  and  flattened,  without  lateral  cartilages, 
but  fringed  on  each  horder  with  pointed  dermal  teeth.  Branchial  clefts  lateral.  The 
two  dorsal  fins  without  spines.     Upper  Cretaceous  to  Recent. 

Pristiophorus,  M.  and  H.  Miocene  to  Recent.  An  undescribed  form  in  the 
Upper  Cretaceous  of  Mount  Lebanon  (Smith  Woodward). 

Family  6.     Pristidae.      Günther.      Saw-fishes. 


Trunk  elongated,  slightly  depressed.  Pedoral  fins  rather  large,  united  with  the 
head,  but  not  extended  to  the  long,  depressed,  sword-like  rostrum,  strengthened  with 
lateral  cartilages,  and  armed  with  a  row  of  large,  dermal  teeth  on  each  lateral  border. 
Branchial  clefts  on  the  ventral  surface.  Teeth  of  the  mouth  minute  and  obtuse. 
Upper  Cretaceous  to  Recent. 

Sclerorhynchus,  Sm.  Woodw.  Teeth  of  rostrum  comparatively  small  and 
not  fixed  in  sockets.  Rostrum  thus  resembles  that  of  Pristiophorus,  but  differs 
from  the  latter  and  agrees  with  Pristis  in  the  great  development  of  a  pair  of 
lateral  cartilages.  S.  atavus,  Sm.  Woodw.,  known  by  nearly  complete  skeletons 
from  Upper  Cretaceous,  Mount  Lebanon. 

Pristis,  Latham.  Teeth  of  rostrum  peg-like,  firmly  implanted  in  sockets  of 
calcified  cartilage.     Middle  Eocene  (Bracklesham  Beds)  to  Recent. 

Propristis,  Dames.  Rostral  teeth  as  in  Pristis,  but  not  implanted  in 
cartilage.     Upper  Eocene  ;  Birket-el-Qurün,  Egypt. 

Family  7.     Rhinobatidae.     Müller  and  Henle. 

Trunk  depressed,  but  elongated.  Pectoral  fins  large,  connected  with  the  head,  but 
the  cartilaginous  rays  not  reaching  the  end  of  the  somewhat  elongated  snout.  BroMchial 
clefts  on  the  ventral  side.  Teeth  small  and  obtuse.  Tail  robust,  with  two  dorsals  and 
a  large  caudal  fin.     Upper  Jurassic  to  Recent. 


SÜB-CLASS  I 


SELACHII 


41 


Bhinobatus,  Bloch  (Euryarthra,  Ag. ;  Spathobatis,  Thioll.),  (Fig.  82). 
fins  without  spines.  Skin  with 
small  shagreen  granules.  Com- 
plete  skeletons  from  the  Litho- 
graphie Stone  of  Bavaria  and 
France,  the  Upper  Cretaceous 
of  Mt.  Lebanon  and  Italy,  and 
the  Upper  Eocene  of  Monte 
Bolca.  Also  later  Tertiary  and 
Recent. 

Asterodemius,  Ag.  Dorsal 
fins  with  small  spines.  Sha- 
green granules  rather  large, 
stellate.  A.  platypterus,  Ag.,  a 
small  species  from  the  Litho- 
graphie Stone  of  Bavaria. 

Belemnobatis,  Thiolliere. 
Lithographie  Stone;  Cerin,  Ain, 
Franee. 

Trygonorhina,  Platyrhina,  M. 
and  H.     Eocene  to  Eecent. 


Family  8.     Tamiobatidae. 

This  family,  represented  by 
the  unique  Tamiobatis  vetustus, 
Eastman,  from  the  Devonian  or 
Lower  Carboniferous  of  Ken- 
tucky, is  of  uncertain  system- 
atie  Position,  but  intermediate 
between  existing  sharks  and 
rays. 


Family  9.     Rajidae.     Müller 
and  Henle.     Skates. 

Trunk  WMch  depressed,  form- 
ing  a  broad,  usually  rhombic  disk 
with  the  pedoral  fins,  which  extend 
from  the  snout  to  the  pelvic  fins. 
The  latter  fins  with  a  strong,  un- 
segmented,  cartilaginous  ray  in 
front.  Teeth  small,  with  bifur- 
cated  root  and  rhombic  crown, 
forming  a  dose  pavement  in  each 
jaw.     Tail  very  slender,  without 


Dorsal 


Fro.  82. 

Ilhinobahis  mirabüis,   Wagn.     Upper  Jurassic  (Lithographie 
,  ,,  7    7    /»  77  Stone);  Eichstädt,  Bavaria.    (From  a  specimen  1-7  m.  long  in 

Spmes,  and  the  Caudal  fin  small  or    the  Palaeontological  Museum,  Munich.) 

dbsent.     Skin  with  small,  pointed 

shagreen  granules  and  larger,   scattered,  spinous,  placoid  tuber  des.     Upper   Cre- 
taceous to  Recent. 


42 


PISCES 


CLASS  I 


Ci/clohatis,  Egerton.  Disk  circular  or  oval,  and  tail  very  short,  without 
median  fins.  Rays  of  paired  fins  few  and  well-spaced,  the  pectorals  united  in 
front  of  the  head.  Pelvic  arch  with  very  large  pre-pubic  processes.  C.  oligo- 
dadylus,  Egerton,  from  Upper  Cretaceous,  Hakel  and  Hajoula,  Mount  Lebanon. 

Baja,  Cuv.  {Adinobatis,  Ag.),  (Fig.  2).  Upper  Cretaceous  (Mount  Lebanon) 
to  Recent.  Dermal  tubercles  of  existing  B.  davata,  Linn.,  in  Pliocene  Crags 
of  Norfolk  and  SufFolk. 


Family  10.     Torpedinidae.      Müller  and  Henle.     Torpedoes. 

Trunk  much  depressed,  forming  a  broad  and  rounded  disk  with  the  pedoral  fins, 
which  do  not  extend  forwards  to  the  broadly  rounded  anterior  end  of  the  head.  Tail 
short  and  fteshy,  with  well-developed  dorsal  and  caudal  fins.  Skin  naked.  An 
eledric  organ  between  the  pedoral  fins  and  the  head.     Eocene  to  Recent. 

Torpedo,  Dum^ril  (Narcobatis,  Blv.).     Sometimes  supposed  to  be  represented 
by  skeletons  in  Upper  Eocene  of  Monte  Bolca,  but  doubtful.     Recent. 
Narcine,  Henle.     Upper  Eocene  of  Monte  Bolca,  and  Recent. 


Family  11.     Trygonidae.     Müller  and  Henle.     Sting-rays. 

Trunk  much  depressed,  forming  a  disk  with  the  very  broad  pedoral  fins,  ivhich 
meet  in  front  of  the  snout,  and  constitute  the  anterior  horder  of  the  head.  Tail  very 
slender,  sharply  separated  from  the  disk,  the  dorsal  fins  usually  replaced  by  several 
stout  imbrirating  spines  of  vasodentine,  which  are  antero-posteriorly  compressed  and 
armed  with  a  row  of  recurved  hooklets  on  each  lateral  border.  Teeth  small,  rhombic 
or  polygonal,  with  bifurcated  root,  and  forming  a  dose  pavement.  Skin  naked,  with 
large  conical  plates  of  vasodentine,  sometimes  fused  into  groups,  usually  raised  into  a 
short  spine.     Tertiary  and  Recent. 

Trygon,  Adanson  (Trygonohatus,  Blv.  ;  Alexandrinum,  Molin),  (Figs.  83,  84). 
Tail   elongated,  with   long,  flattened   dorsal   spines.     Dermal   plates  of  very 
^  ^  ^  variable   form   and   size.      T.  gazolae,  Ag. ;    2\ 

(Alexandrinum)  molini,  Zigno ;  T.  zignoi,  Molin, 
known  by  nearly  complete  skeletons  from  the 
Upper  Eocene  of  Monte 
Bolca.  Isolated  dermal 
plates  (Fig.  84)  have 
been  described  as  refer- 
able  to  Raja,  Acipenser, 
Dynatobatis,       Larrazet, 


Fig.  83. 
Trygon    rugostis,    Probst. 


Tooth,  an- 
terior (A),  posterior  (B),  aiul  lateral  (C), 
aspects,  enlarged,  and  the  sanie  iiat.  size 

gLtT"'^''''""^'  «^^^""«^"<^^^^'-  and  Acanthobatis,  Larr 

Taeniura,  Urolophus, 
M.  and  H.  Upper  Eocene  (Monte  Bolca)  and 
Recent. 

Xiphotrygon,  Cope  (Heliobatis,  Marsh).     Resembling 
Trygon,  but  teeth  cuspidate.'     X  acutid^ens,  Cope,  known   ..IS^ji^'i^'''^^^ 
by  complete  skeletons  from  Eocene  Green  River  Shales  hV^^^«^^\  "^^-^  ^'^^-    ^locene 

f  "Wt--— -• (Molasse);  Baltringen. 


Fig.  84. 


yoming. 
Oncobatis,  Leidy. 


Dermal  tubercles.     Pliocene  ;  Idaho. 


SüB-CLASS  I 


SELACHII 


43 


I 


Family #12.     Myliobatidae.     Müller  and  Henle.     Eagle-rays. 

Trunk  much  depressed,  forming  a  broad  disk  with  the  very  large  ptdoxaLfins^ 
which  are  interrupted  at  the  sides  of  the  head,  hut  reappear  as  one  or  a  pair  of  small 
cephalic  fins  at  the  extremity  of  the  snout.  Tail  very  slender,  with  one  or  several 
flattened  sphies  hehind  the  single  dorsal  fin.  Teeth  rather  large,  forming  a  dose 
pavement  in  both  jaws.     Skin  naked.     Cretaceous  (?),  Tertiary  and  Recent. 

Most  of  the  survivirig  genera  of  this  family  are  represented  iii  the  Tertiary 
by  isolated  teeth  and  spines,  or  by  the  complete  dentition. 

?  Ftychodus,  Ag.  (Aulodus,  Dixon),  (Figs.  85,  86).  Known  only  by  the 
dentition  and  vertebrae,  and  hence  of  uncertain  systematic  position.  Teeth 
quadrangular,  with  a  raised  crown,  which  is 
transversely  or  radially  ribbed,  and  sharply 
separated  by  a  constriction  from  the  smaller, 


Fig.  85. 

Ftychodus  polygyras,  Ag.     Tooth,  ural  and  posterior  view; 
nat.  sizf.     Greensaiid  ;  Kegensbnrg. 


Fig.  86. 

Ftychodus  decurrens,  Ag.  Uiagrain  of 
arrangeinent  of  teeth  in  npi)er(^),  and 
Iower  (B)  jaws,  niuch  reduced.  Lower 
Chalk  ;  England  (after  Smith  Wood- 
ward). 


smooth  root.     The  teeth  are  solid,  and  the  ganodentine  investing  the  crown 

is  thick.     They  are  arranged   in  about  thirteen  antero-posterior   series   (Fig. 

86).     In  one  jaw,  presumably  lower,  the  median  series  of  teeth  is  the  .largest, 

and  the   lateral  rows  are  dis- 

posed  symmetrically,  diminish- 

ing  in  size  outwards.     In  the 

opposing  jaw  the  median  series  /  /K  ^  __— /y<^\ 

is    very    small,    and    the    first  /   /  fXl^^^y_ ir^ 


.T;nvs  of  Recent  Myliobatis,  lateral  aspect. 


Jaws  of  MylinhoMs  aquüa,  Cuv.     Anterior  aspect.     Recent : 
Mediterranean  (after  Agassiz).. 


lateral   row   on   each   side   large,   with  the  outer   lateral   series   diminishing. 
Common  in  the  Chalk  of  Europe  and  North  America,  rarer  in  the  Greensand. 


44 


PISCES 


CLASS I 


Myliohntis  toliapicus,  Ag.  liiiperfect 
dentition.  Middle  Eoceiie ;  Bracklesham, 
Sussex. 


Promyliohatis,  Jaekel.    A  skeleton  from  the  Upper  Eocene  of  Monte  Bolca, 
apparently  showing  pectoral  fins  less  completely  interrupted  at  side  of  head 

than  in  recent  Myliobatis,  otherwise  resembling 
the  latter.     P,  gazolae,  Zigno  sp. 

Myliobatis,  Cuv.  {Fastinaca,  Gronow),  (Figs. 
87-90).  The  dental  pavement  of  the  jaws 
consists  of  seven  antero-posterior  rows  of  hex- 
angular  flattened  teeth  closely  pressed  together. 
The  lower  dentition  is  longer  and  less  arched 
than  that  of  the  upper  jaw. 
In  young  examples  all  the 
teeth  are  similar  in  form  and 
size,  but  during  growth  the 
median  series  rapidly  in- 
creases  in  width,  and  event- 
ually  becomes  from  three  to 
six  times  as  broad  as  long, 
while  the  shape  of  the  lateral 
series  remains  unchanged. 
The  strongly  developed  root  of  each  tooth  is  marked  with 
parallel  grooves  on  its  lower  and  lateral  faces.  Numerous 
species  represented  by  the  dentition  in  the  Tertiaries,  and 
caudal  spines  also  known.  M.  dixoni,  Ag. ;  M.  striatus, 
Buckl. ;  M.  toliapicus,  Ag.,  from  English  Eocene.  M. 
pentoni,  Sm.  Woodw.,  the  largest  known  species,  from 
Eocene,  Mokattam  Hills,  Cairo.  M.  magister,  Leidy,  the 
largest  American  species,  known  by  complete  dentition 
from  the  South  Carolina  Eocene. 

Bhinoptera,  Müller  (Zygobates,  Ag. ;  Mylorhina,  Gill). 
Dentition  of  both  jaws  strongly  arched  antero-posteriorly. 
Teeth  flattened  and  hexangular,  in  five  to  nine  antero- 
posterior  rows,  and  mostly  broader  than  long,  but  diminish- 
ing  in  breadth  outwards.  Tertiary  and  E-ecent.  B.  daviesi, 
Sm.  Woodw.,  from  London  Clay,  Sheppey. 

Aetobatus,  M.  and  H.  (Goniobatis,  Le  Hon).     Teeth  very 
broad,    in    a    single    antero-posterior    series.       Tertiary    and    Recent ; 
distribution. 


Fig.  90. 
Myliobatis  serratus,  H. 
V.   Meyer.      Caudal  fin- 
spiiie.  Oligocene ;  Wein- 
heim, near  Alzey. 


wide 


Order  5.     HOLOCBPHALI.     Chimaeras. 

Pterygoquadrate  arcade  completely  and  immovably  fused  with  the  cranium. 
Mandible  provided  with  a  very  large  dental  plate  on  each  side,  meeting  one  or  two 
pairs  of  dental  plates  in  the  upper  jaw.  Gilt  clefts  covered  by  a  fold  of  skin,  so  that 
there  is  only  one  external  opening.  Vertebral  azis  not  distinctly  segmented,  and  the 
notochord  surrounded  by  numerous  partially  calcified  rings  of  cartilage.  Paired  fins 
with  tivo  or  three  short  basal  cartilages  ;  pelvic  fins  of  male  with  appended  claspers. 

The  Holocephali  occupy  a  unique  position  among  the  Selachii,  on  account 
of  (1)  the  incompletely  segmented  character  of  the  vertebral  axis,  in  which  the 
number  of  the  cartilaginous  rings  considerably  exceeds  that  of  the  arches  and 
processes;  and  (2)  the  fusion  of  the  upper  jaw  with  the  skull.     Their  trunk 


r 


SüB-CLASS  I  SELACHII  45 

resembles  that  of  the  sharks,  while  the  dentition  is  distinguished  by  the  remark- 
ably  peculiar  form  and  structure  of  the  few  very  large  teeth  or  dental  plates. 
Of  the  four  surviving  genera,  Ghimaera  lives  off  the  European  coasts,  Japan, 
and  the  Cape  of  Good  Hope ;  CallorhyncJms  in  the  seas  of  the  southern  hemi- 
sphere ;  Harriotta  in  the  deep  Atlantic  off  North  America ;  and  Rhinochimaera  in 
deep  water  off  Japan.  In  all  these  genera  the  anterior  dorsal  fin  is  provided 
in  front  with  a  strong  spine,  which  is  supported  by  a  broad  plate  of  cartilage 
fixed  to  the  vertebral  column,  and  is  united  with  this  plate  by  a  cartilage 
articulation.  Besides  the  fin  spine,  the  males  of  recent  forms  bear  on  the 
frontal  region  a  spine  which  is  rounded  in  front  and  covered  with  prickles,  as 
well  as  smaller  prickly  spines  in  front  of  the  pelvic  fins.  The  long  copulatory 
Organs  are  also  strengthened  by  thin  calcified  rods.  The  skin  of  the  existing 
genera  is  naked,  but  in  some  extinct  genera  it  is  partly  covered  with  shagreen 
granules  and  plates.  A  remarkable  peculiarity  of  the  Chimaeroids  consists  in 
the  unusually  conspicuous  character  of  the  mucous-canals,  which  traverse  the 
skin  of  the  head  and  form  the  very  prominent  lateral  line  of  the  trunk.  These 
are  surrounded  by  numerous,  closely  arranged,  calcified  rings  of  cartilage. 

The  existing  representatives  of  the  Holocephali  are  only  an  insignificant 
remnant  of  a  former  much  more  extensively  developed  group  of  Selachians, 
which  appears  first  in  the  Devonian,  and  is  perhaps  genetically  connected  with 
the  Cochliodontidae. 

Family  1.     Ptyctodontidae.     Smitli  Woodward.^ 

Known  only  hy  dental  plates,  which  are  laterally  compressed,  seem  to  form  a 
Single  pair  meeting  at  the  Symphysis  of  eachjaw,  and  exhibit  either  few  tritoral  areas, 
or  sharp  cutting  edges.     Devonian. 

FtydoduSj  Pander  {Aulacosteus,  Eichwald  ;  Binodus,  Newb.  and  Worth.). 
Tritoral  area  composed  of  very  hard,  punctate,  superimposed  laminae,  arranged 
obliquely  to  the  iunctional  surface.  F.  oUiquus,  Pander,  from  Middle  Devonian, 
North  Russia.  P.  molaris,  East. ;  Eifel  Devonian.  P.  calceolus,  Newb.,  and 
P.  ferox,  East. ;  Middle  and  Upper  Devonian,  Wisconsin,  Illinois,  and  Iowa. 

Ehynchodus,  Newb.  Dental  plates  with  sharp  cutting  edges,  and  no  well- 
differentiated  tritors.      North  America,  and  the  Eifel,  Germany. 

Palaeomylus,  Sm.  Woodw.  Robust  teeth,  with  broad  symphysial  surface, 
and  one  punctate  tritoral  area,  not  laminated.     North  America. 

Family  2.     Squaloraiidae.      Smith  Woodward. 

Trunk  depressed  and  elongated,  and  head  produced  into  a  long,  slender  snout. 
Lower  dentition  comprising  one  pair,  upper  dentition  two  pairs  of  thin  corrugated 
dental  plates  without  definite  tritors.  Males  with  a  prehensile  spine  on  the  snout. 
Dorsal  fin  spine  absent.  Numerous  conical  or  stellate  ■  dermal  tuhercles.  Lower 
Jurassic. 

Squaloraja,  Riley  (Spinacorhinus,  Ag.).  Tail  tapering  to  a  point.  Rostral 
spine  with  expanded  base,  tapering  to  a  point  in  front.  Yertebral  rings  well 
calcified,  consisting  of  several  concentric  lamellae.  S.  polyspondyla,  Ag.,  known 
by  nearly  complete  skeletons  0'45  in  length,  from  the  Lower  Lias  of  Lyme 
Regis,  Dorsetshire. 

^  Eastman,  C.  R.,  Dentition  of  Devonian  Ptyctodontidae  (Anier.  Nat.  vol.  XXXII.),  1898. 


46 


PISCES 


CLASS I 


Family  3.     Myriacanthidae.     Smitli  Woodward. 


Trunk  elongated.  Two  upper  pairs  and  one  lower  pair  of  thin  Jental  plates, 
also  a  stouf,  median,  incisor-like  tooth  at  the  Symphysis  of  the  inandible.  Head  with 
a  few  dermal  plates.  Males  with  a  prehensile  spine  on  the  snout.  Anterior  dorsal 
fin  above  the  pedorals,  with  a  long,  straight,  robust  spine.     Jurassic. 

Myriacanthus,  Ag.  (Prognathodus,  Egerton  ;  Metopacanthus,  Zittel).  Rostrum 
with  a  terminal  cutaneous  flap.  Anterior  upper  dental  plate  smaller  than  the 
posterior  plate.  Dorsal  fin  spine  long  and  slender,  somewhat  laterally  com- 
pressed,  with  a  large  internal  cavity ;  sides  ornamented  with  small  tubercles  ; 
a  series  of  large,  thorn-shaped  tubercles  arranged  along  each  edge  of  the 
fiattened  posterior  face,  passing  into  a  single  median  row  distally,  and  a  single 
series  of  similar  denticles  on  the  anterior  border.  Kostral  spine  elongated 
'and  pointed,  with  expanded  base.  Dermal  plates  tuberculated.  M.  paradoxus, 
Ag.,  and  M.  granulatus,  Ag.,  from  Lower  Lias  of  Lyme  Regis. 

Chimaeropsis,  Zittel  (Fig.  91).  Mandibular  dental  plates  (md),  slightly 
arched,    with   a   large    tritoral    area ;    the    symphysial    tooth    (x)    externally 


Fig.  91. 

Chimaeropsis  paradom,  Zitt.  Upper  Jurassic  (Litliographic  Stoue) ;  Bichstädt,  Bavaria,  1/2  iiat.  size. 
md,  Mandibular  tooth  ;  p,  Minder  upper  tooth;  v,  Anterior  upper  tooth  in  side  view;  v^,  8anie  from  lower 
side  ;  x,  Slender  premandibular  tooth. 

(inferiorly)  convex,  internally  (superiorly)  fiat  or  concave.  Anterior  (v)  and 
posterior  (p)  upper  dental  plates  triangulär,  the  former  not  smaller  than  the 
latter,  and  tapering  in  front,  the  latter  tapering  behind.  Fin  spine  as  in 
Myriacanthus.  Body  covered  with  small,  conical,  radiately  grooved  placoid 
scales.     Upper  Jurassic  (Lithographie  Stone)  of  Bavaria. 


Family  4.     Chiraaeridae.      Chimaeras.i 

Trunk  elongated,  shark-like.  Teeth  forming  two  pairs  of  robust  dental  plates  in 
the  upper  jaw,  the  foremost  the  smaller,  both  pairs  thickened  and  closely  apposed  in 
the  longitiulinal  mesial  line  of  the  mouth  •;  lower  dentition  comprising  a  single  pair  of 
beak-shaped  plates  meeting  at  the  Symphysis ;  the  plates  usually  with  several  tritors. 
Pedoral  fins  very  large,  fan-like,  with  simple,  horny  rays  ;  anterior  dorsal  fin  above 
the  pedorals,  ivith  a  large  spine  articulated  to  a  cartilaginous  base  ;  posterior  dorsal 

1  Xewton,  E.  T.,  Tlie  Chiniaeroid  Fislies  of  the  Britisli  Cretaceous  Rocks  (Meni.  Geol,  Survey, 
Mon.  No.  IV.),  1878. 


SUB-CLASS  I 


SELACHII 


47 


fin   low,   inuch  extended.      Skin  naked,   or  with   shagreen  gramUes.      Jurassic   to 
Recent. 

hchyodus,  Egerton  (Leptacanthus,  Ag. ;  Auluxacanthus,  Sauvage ;  Clmnaer- 
acanthus,  Quenstedt),  (Fig.  92).  Lower  dental  plates 
rhomboidal,  with  a  narrow  symphysial  facette  ;  upper 
part  of  outer  face  covered  with  a  thick  layer  of 
dentine,  and  oral  margin  sharp ;  four  rough  punctate 
tritors  present.  Posterior  upper  dental  plates  tri- 
angulär, tapering  in  front,  with  four  tritors ;  anterior 
upper  teeth  Square,  antero- posterior ly  compressed. 
Dorsal  fin  spine  laterally  compressed,  smooth  or 
longitudinally  striated,  with  a  double  longitudinal 
series  of  denticles  on  the  hinder  face.     Males  with  a  '  f 

short,  arched  head  spine,  bearing  a  Cluster  of  denticles  _^i«^  ^^i 
at  the  end.  Nearly  complete  skeletons  of  /.  avitus, 
Meyer  sp.  (Fig.  92),  and  /.  quenstedti,  from  the 
Lithographie  Stone  of  Bavaria.  Detached  teeth 
from  the  Bathonian  (Stonesfield  Slate)  to  the  Upper 
Cretaceous  of  England,  France,  Germany,  and  Switzer- 
land ;  also  from  Cretaceous  of  Amuri  Bluff,  New 
Zealand. 

Ganodus,  Ag  Dentition  as  in  Ischyodus,  but 
posterior  upper  dental  plate  deeply  excavated 
behind,  with  a  double  longitudinal  series  of  numer- 
ous  small  tritors.  Bathonian  (Stonesfield  Slate), 
England.      G.  oweni,  Ag.,  and  other  species. 


^: 


Fio.  93, 

Etlaiihodon'sedqvncki,  An.  sp.  Teeth,  1/2  nat.  size.  I.ower  Chalk  ;  I.ewes. 
Hill,  Left  niaiulibular  tooth,  inner  aspect ;  p,  Left  hinder  npper  tooth,  oral 
aspect ;  V,  Ijeft  anterior  upper  tooth,  inner  aspect ;  a,  Tritors ;  sym,  Syni- 
Ithysial  border  (after  E.  T.  Newton). 


Fig.  S>2. 
Ischyodua  ai'itu^,  H.  v.  Meyer. 
Almost  complete  skeleton,*  1/2 
nat.  size.  Upper  Jurassic 
(Lithopraphic  Stone) ;  Eichstädt 
(after  II.  v.  Meyer). 


Fachymißus,  Brachymylus,  Sm.  Woodw.     Upper  Jui-assic  ;  England. 


48 


PISCES 


CLASS I 


Edaphodon,  Buckland  (Passalodon,  Buckl. ;  Eumylodus^  Mylognathus,  Leidy  ; 
Dipristis,  Marsh;  Leptomylus,  Cope),  (Fig.  93).  Lower  dental  plates  with  a 
broad  symphysial  facette ;  posterior  upper  dental  plates  tapering  in  front, 
truncated  behind,  and  with  three  tritors.  Cretaceous,  Eocene,  and  Oiigocene 
of  Europe  and  North  America. 

Elasmodedes,  Newton  (Elasmognathus,  Newton,  non  Gill).  Mandibular  teeth 
laterally  compressed  and  trenchant,  with  a  series  of  small  tritors  along  the 
oral  border.     E.  willetti,  Newton,  from  Lower  Chalk,  Kent. 

Amylodon,  Storms.     Lower  Miocene  (Rupelian) ;  Belgium. 

Elasmodiis,  Egerton.  Upper  Cretaceous  of  Belgium  ;  Eocene  of  England 
and  Prussia. 

Dental  plates  of  the  existing  genus  Callorhynchus,  Gronow,  have  been 
identified  from  the  Cretaceous  of  Amuri  Bluff,  New  Zealand ;  of  the  existing 
genus  Chimaem,  Linn.,  from  the  Upper  Tertiary  of  Europe  and  Java. 


roCi-Cv 


Ichthyodorulites. 

Fossil  fin  spines  consisting  of  dentine  or  vasodentine,  and  thus  presumably 
referable  to  the  Selachii,  are  frequently  found  isolated 
especially  in  the  Palaeozoic  formations,  and  can  only  be 
in  part  assigned  to  definite  genera.  These  are  therefore 
described  under  provisional  generic  names.  Most  of  them 
are  bilaterally  symmetrical,  and  may 
be  regarded  as  median  dorsal  spines  ; 
but  several  are  distinctly  rights  and 
lefts,  and  belong  either  to  the  paired 
fins,  as  in  Acanthodidae,  or  to  the  side 
of  the  head,  as  in  Menaspis  among 
Cochliodontidae.  In  the  unsym- 
metrical  spines,  the  base  is,  as  a  rule, 
abruptly  truncated  ;  in  the  bilaterally- 
symmetrical  dorsal  spines,  on  the  other 
band,  it  is  usually  elongated  and  tapers 
to  the  proximal  end. 

Among  the  Ichthyodorulites  not 
yet  referable  with  certainty  to  definite 
genera  or  families,  the  following  may 
be  enumerated  . — 

(a)  Slender,  bilaterally-symmetrical 
spines,  with  a  smooth  base  sharply 
separated  from  the  exserted  portion ;  internal  cavity  open 
posteriorly  towards  the  base.  Probably  for  the  most  part 
referable  to  the  Cestraciontidae.  Onchus,  Ag.  (Fig.  94); 
Upper  Silurian  and  Devonian,  Europe  and  eastern  North 
America.  Ctenacanthus,  Ag.  (Fig.  95),  possibly  the  fin 
spines  of  Orodus ;  Lower  Carbonif erous,  Europe  and  North 
America.  Homacanthus,  Ag. ;  Devonian  and  Lower  Carboni- 
ferous.  AcondylacantJms,  St.  J.  and  Worth. ;  Asteroptychius, 
M'Coy  ;  Lispacanthus,  Davis  ;  Geisacanthus,  St.  J.  and  Worth.; 
Lower  Carboniferous.    Lepracanthus,  Owen  ;  British  Coal  Measures.     IFodniJca 


Fig.  94. 

Onchus  tenuistriatus,  Ag. 
Fin-spine,  iiat.  size.  Upper 
Silurian ;  Ludlow,  England. 


Fig.  95. 

Ctenacanthus  denticu- 
latus,  M'Coy.  i/2!nat. 
size.  Carboniferous 
Liniestone ;  Monaduff, 
Ireland  (after  M'Coy). 


SÜB-CLASS  I 


SELACHIl 


49 


Münster ;    Permian  (Kupferschiefer 
Ag. ;  Rhaetic  and  Lower  Jurassic. 

(b)  Slender,  bilaterally  -  sym- 
metrica! spines,  with  little  or  no 
smooth  inserted  portion,  and  in- 
ternal cavity  only  open  at  the 
proximal  end.  Gnathacanthus, 
Davis;  Lower  Carboniferous, 
Armagh,  Ireland.  Pristacanthus, 
Ag.  ;  Bathonian,  Oxfordshire  and 
Normandy. 

(c)  Right  and  left  paired  spines, 
most  probably  connected  with  fins. 
Machaeracanthus,  Newb.   (Fig.  97) ; 

Heteracanthus, 
Newb.  ;  Hapla- 
canthus,  Ag.  De- 
vonian;  Eürope 
and  North 
America.  Gyra- 
canthus,  Ag. 
Lower  Devonian 
(Canada)    to    Upper 


of   Germany),  (Fig.   96).      Nemacanthus, 


Wodnika  striatula, 
Riecheisdorf,  Hesse. 


Fig.  SHi. 

Münst.     Enlarged.     Kupferschiefer ; 
A,  Fin-spine.    B,  Shagreen  granules. 


Carboniferous    (Europe    and    North 
America). 

~  (d)  Paired  spines,  usually  with  a 
broad,  truncated  base,  a  large  internal 
cavity  and  the  outer  face  tuberculated. 
Probably  lateral  head  spines,  as  in 
Menaspis  among  Cochliodontidae.  Ora- 
canthus,  Ag.  {Flatyacanthus,  M'Coy ; 
Pnigeacanthus,  St.  J.  and  Worth. ;  Phodera- 
canihus,  Davis.)  Carboniferous  of  Europe 
and  North  America  (spines  already 
observed  on  either  side  of  head  in  one 
example  of  0.  armigerus,  Traquair,  from 
Calciferous  Sandstones  of  Eskdale, 
Dumfries).  Physonemus,  M'Coy  (Xystra- 
canthus,  Leidy  ;  Drepanacanthus,'N ewh.) ; 
Erismacanthus,  M'Coy  ;  Gampsacanthus^ 
St.  J.  and  Worth.  (Fig.  98);  Lecra- 
canthus,  St.  J.  and  Worth.  ;  Dipria- 
canthus,  M'Coy,  etc.  Lower  Carboni- 
ferous. 

(e)  Spines  of  entirely  doubtful  posi- 
tion.  Cynopodius,  Traquair.  Lower 
Carboniferous ;  Scotland.  Eudenius^ 
Traquair.       Coal    Measures ;    Scotland, 

England,   and   Ohio,    U.S.A.       Stethacanthus,   Newb.      Upper  Devonian   and 

Lower  Carboniferous ;  Ohio,  Illinois,  and  Iowa. 


^y. 


Ä 


Fig.  97. 

Machacracanthus  vmjor 
Newberry.  Middle  De 
vonian ;  Sandusky,  Ohio, 
1/2  nat.  size  (after  New 
berry). 


Gampsacanthus  typus, 
St.  John  and  Worthen. 
Carboniferous  Linie- 
stone; St.  Louis, 
Missouri  (after  St.  John 
and  Worthen). 


VOL.  II 


50  PISCES  CLAss  I 


Sub-Class  2.     OSTRACODERMI.     Cope. 

Early  Palaeozoic  fishes  with  persistent  notochord,  and  endoskeleton  not  calcified. 
Mandihle  and  arches  for  paired  fiiis  apparently  ahsent.  Exoskeleton  well  developed, 
the  head  and  anterior  portion  of  the  trunk  usually  covered  with  plates.  Mouth 
without  hard  parts. 

The  Ostracoderras  form  one  of  the  most  characteristic  groups  of  the  early 
Palaeozoic  fish-fauna ;  but  their  true  systematic  positioii  is  still  uncertain. 
Their  remains  were  formerly  compared  with  the  armour  of  reptiles  such  as 
tortoises,  and  also  with  crabs  and  water-beetles ;  while  more  lately  they  have 
even  been  supposed  to  exhibit  resemblances  to  Arachnids.  They  were  first 
recognised  as  fishes  by  Agassiz,  and  referred  by  him  to  the  Ganoidei.  Unless 
appearances  in  the  fossils  are  deceptive,  they  are  distinguished  from  all  typical 
fishes,  and  agree  with  the  Cyclostomi  in  the  lack  of  a  lower  jaw  and  of  arches 
for  paired  limbs ;  but  there  seems  to  be  evidence  of  paired  nasal  openings  in 
Pterichthys  and  Bothriolepis. 

Four  Orders  of  Ostracophores  may  be  recognised  as  follows  : — Heterostraä, 
Anaspida,  Aspidocephali,  and  Antiarcha.  In  the  first,  the  exoskeleton  sometimes 
consists  of  placoid  tubercles  of  dentine,  as  in  sharks ;  in  the  second  the 
tubercles  on  the  head  region  are  never  fused.  In  the  more  typical  Hetero- 
straci,  as  also  in  the  Aspidocephali  and  Antiarcha,  this  primitive  armour  is 
modified  so  that  the  head  and  anterior  abdominal  region  become  invested  with 
dermal  plates,  which  are  usually  as  well  developed  as  in  modern  sturgeons 
and  certain  bony  fishes  (Siluridae).  The  sub-class  is  restricted  to  the  Upper 
Silurian  and  Devonian. 

Order  1.     HETEROSTRACI.     Ray  Lankester.i 

Exoskeleton  consisting  of  shagreen,  plates,  or  scales,  without  hone  cells  ;  each  fully 
formed  plate  comprising  three  superimposed  layers — an  inner  ^'nacreous"  layer  of 
lamellae,  a  relatively  thick  middle  zone  with  numerous  vacuities,  and  an  outer  hard 
layer  of  vaso-dentine.  Dorsal  shield,  when  present,  of  few  pieces,  and  orhits  wide 
apart,  laterally  placed.     No  paired  appendages. 

Family  1.     Ooelolepidae.     Pander. 

Head  and  trunk  relatively  large  and  depressed,  completely  covered  with  placoid 
tubercles  of  dentine,  scarcely  if  at  all  fused  into  groups ;  the  small,  slender  caudal 
region  sharply  constricted  from,  the  head  r'egion  and  distinctly  heterocercal.  Upper 
Silurian  and  Lower  Devonian. 

The  dermal  tubercles  of  genera  of  this  family  have  long  been  known  from 
the  Upper  Silurian  of  England  and  the  Isle  of  Oesel  in  the  Baltic  Sea ;  but 
until  the  discovery  of  complete  specimens  in  the  Upper  Silurian  of  Lanark- 

^  Alth,  A.  von,  Ueber  Pteraspis,  Gyathaspis,  iiiid  Scaphaspis  (Beitr.  Palaeout.  Oesteri.- 
Ungarns,  vol.  II.),  188Q.—Huxley,  T.  IT.,  On  üeplmlcisptis  and  Pteraspis  (Quart.  Journ.  Geol.  Soc. 
voLs.  XII.,  XIV.,  XVII.),  1856,  1858,  1%Q1.—Kner,  R.,  Ueber  Cephalaspis  lloydü  und  levoisü 
(Haidinger's  Naturw.  Abhandl.  vol.  I.),  1847. — Kunth,  A.,  Ueber  Pteraspis  (Zeitschr.  deutsch, 
geol.  Ges.  vol.  XXIV.),  1872. — Lankester,  Ray,  and  Povyrie,  J.,  A  Monograph  of  the  Fishes  of  the 
Old  Red  Sandstone.  I.  Cephalaspidae  (Mon.  Palaeont.  Soc),  1868. — lioemer,  Ferd.,  Ueber  Palaeo- 
teuthis  diinensis  (Palaeontogr.  vol.  IV.),  1856. — Traquair,  R.  H.,  Report  on  Fossil  Fishes,  etc. 
(Trans.  Roy.  Soc.  Edinb.  vol.  XXXIX.  Nos.  21,  32),  1899. 


SUB-CLASS  II 


OSTRACODERMI 


51 


&m 


shire,  they  were  commonly  supposed  to  belong  to  sharks.  The  latter  discovery 
is  coiisidered  by  Traquair  to  indicate  some  close  relationship  between  the 
Ostracophores  and  the  primitive  Selachii. 

Thelodus,  Ag.  {öoelolepis,  Pachylepis,  Thelolepis,  Pander ;  Cephalopteriis, 
Powrie;  Turinia,  Traq.),  (Fig.  99).  Dermal  tubercles  small,  quadrangular, 
and  nearly  uniform.  A  small  dorsal  fin  near  base  of 
heterocercal  tail.  No  enlarged  ridge  scales.  T.  parvidens, 
Ag. ;  detached  tubercles  in  Ludlow  Bonebed  and  Oesel 
Limestone.  T.  scoticus,  Traq. ;  complete  skeletons  in 
Upper   Ludlow,   Logan   Water,   Lanarkshire.      T.  pagei,  fio.  99. 

Powrie  sp.  ;    complete  skeleton,  Lower  Old   Ked   Sand-      Theiodns  parvidens,  Ag. 

rn-TT-n-n      i-        ^  '  DeiTTial  tubercles,  nat.  size 

Stone,    iurin  Hill,  J^  Oriarshire.  (above) and  enlarged.  Upper 

Lanarkia,  Traq.     Dermal  tubercles  are  small,  pointed,   8i^™(L"diowBoneBed); 

hollow  spines,  not  of  uniform  size.     L.  horrida,  Traq., 

and  other  species  represented   by  skeletons  in  the  Upper  Silurian   Passage 

Beds  of  Birkenhead  Burn  and 
Seggieholm,  Lanarkshire. 

Family  2.     Psammosteidae. 
Traquair. 

Dermal  armour  of  head  region 
more  or  less  completely  fused  info  large 
plates.  External  layer  of  each  dermal 
plate  forming  a  tubercular  ornament. 
Dermal  sense  organs  not  penetrating  the 
tissue  of  the  armour.     Devonian. 

Fsammmteus,  Ag.  (Placosteus, 
Ag. ;  Fsammolepis,  Ag.).  External 
Ornament  of  very  closely  arranged, 
rounded,  or  elongated  tubercles 
/>  ^  which  are  usually  crimped  rpund 
the  margin.  Orbit  probably  enclosed 
in  the  shield.  Paired  spines  (of  un- 
certain  position)  broad  and  tri- 
angulär, with  a  large  internal  cavity 
and  Short  base  of  insertion.  Large 
ridge  scutes  on  the  tail,  ornamented 
as  the  body  shield  and  paired  spines. 
P.  maeandrinus,  Ag.,and  P.paradoxus, 
Ag.,  from  Upper  Devonian,  Russia. 
P.  taylori,  Traq.,  from  Upper  Old  Red 
Sandstone,  Elgin.  Other  species  from 
the  Lower  Old  Red  Sandstone  of 
west  of  England,  and  from  Upper 
Devonian,  Spitzbergen. 

Drepanaspis,  Schlüter  (Fig.  100). 

l,   Postero-lateral  plates;   p.v.l,   Postero-ventro-lateral    Head    reglOU  COVered    Wltn  OUe  large 
l.iates  ;  r,  Rostral  plates  ;  x,  Orbits.    1/4  (after  Traquair).    ^g^Jj^n     plate,     tWO     pOStCrO  -  lateral 

plates,  two  rostral  plates,  and  intervening  small  polygonal  plates.  Tail  as  in 
Psammosteus.  D.  gemuendenensis,  Schlüt.,  from  Lower  Devonian,  Gemünden,  Eifel. 


Drepanaspis  gemuendencnsis,  Schlüter.  Restored  out- 
line of  ventral  aspect,  surface  ornament  omitted.  Lower 
Devonian  ;  Gemünden,  Eifel.    m.v,  Median  ventral  plate; 


52 


PISCES 


Family  3.     Pteraspidae.     Smitli  Woodward. 

Dermal  armour  of  head  region  completely  fused  into  large  plates.  External  layer  of 
each  dermal  jplate  forming  an  ornament  of  very  fine,  concentric,  dosely  arranged  ridges, 
parallel  with  the  outer  margin  ;  middle  layer  with  large  polygonal  cancellae.  Dermal 
sense  organs  well  developed,  arranged  in  canals  traversing  the  middle  layer  of  the 

shield  and  opening  hy  a 
double  series  of  pores  ex- 
ternally.  Ventral  shield 
simple.  Tail  presumably 
heterocercal,  and  scales 
of  caudal  region,  when 
preservedj  numerous  and 
rhomboidal.  Upper 
Silurian  and  Lower 
Devonian. 

Three  genera  of  this 
familyare  distinguished 
according  to  the  com- 
plexity  of  the  dorsal 
shield.  The  simple 
ventral  shield,  similar 
in  each  form,  was 
originally  mistaken  for 
dorsal  armour,  and 
named  Scaphaspis  hy 
Lankester. 

Pteraspis,  Kner 
(Palaeoteuthis,  Archaeo- 
teuthis,  F.  Eoemer), 
(Figs.  101-103).  Dor- 
sal shield  arrowhead- 
— a  large  central  disc ; 


Fig.  101 


A,  B,  Pteraspis  rostrata,  Ag.  sp.  Lower  Cid  Red  Sandstone  (Cornstones) ; 
Herefordshire.  A,  Dorsal  shield,  1/2  nat.  size,  restored.  B,  Ventral  shield 
(Scaphcu^pis  lloydi,  Ag.  sp.),  2/3  nat.  size  (after  Ray  Lankester).  C,  Dorsal 
and  ventral  shields  of  Pteraspis,  lateral  aspect,  restored  from  a  specinien 
found  in  Galicia  (after  Alth).' 

shaped,  consisting  of  seven  separately  calcified  plates 


Fig.  10;^. 
Pteraspis  rostrata,  Ag.  sp.    Piece 
of  shield ,  much  magnified.   a,  Upper, 
h,  Middle,  and  c,  Lower  layer  (after 
Ray  Lankester). 


Fig.  103. 

Pteraspis  rostrata,  Ag.  sp.  Vertical  section  of  head 
shield  parallel  with  a  longitudinal  rib,  highly  mag- 
nified (after  Ray  Lankester). 


a  triangulär  rostral  plate  in  front ;  a  median  spine  behind ;  a  pair  of  orbital 
plates,  completely  enclosing  the  orbit  on  either  side,  and  partially  inserted 
between  the  rostrum  and  central  disc ;   and  a  pair  of  lateral  cornua,  each 


SÜB-CLASS  II 


OSTRACODEKMI 


53 


pierced  by  a  large,  apparently  branchial  foramen.  P.  rostrata,  Ag.  sp.  (Fig. 
101),  and  other  species  from  the  Lower  Old  Red  Sandstone  of  England, 
Scotland,  Rhenish  Prussia,  and  Galicia ;  also  from  the  Upper  Silurian  of 
Galicia,  and  probably  from  the  Lower  Devonian  of  Spitzbergen. 

Falaeaspis,  Claypole  (Holaspis,  Lank.  non  Gray).  Dorsal  shield  apparently 
simple,  without  posterior  spine  ;  orbits  merely  forming  notches.  P.  americana, 
Glay.,  from  Upper  Silurian  (Onondaga  Group),  Pennsylvania.  P.  sericea, 
Lank.  sp.,  from  Lower  Old  Red  Sandstone,  Monmouthshire. 

Cyathaspis,  Lank.  {Diplaspis,  Matthew).  Dorsal  shield  consisting  of  a  large 
central  disc  ;  two  long  and  slender  lateral  cornua,  which  are  notched  anteriorly 
by  the  orbits  and.  pierced  further  back  by  the  supposed  branchial  foramen, 
and  a  short  and  broad  rostral  plate.  C.  banksi,  Huxley  and  Salter  sp.,  from 
Upper  Silurian  (Ludlow  Bone-bed  and  Passage  Beds)  of  Herefordshire.  C. 
schmidti,  Geinitz,  from  Wenlock  Limestone  of  Isle  of  Gotland.  Other  species 
from  corresponding  formations  in  Germany,  Galicia,  and  New  Brunswick. 
The  so-called  Scaphaspis  ludensis,  Salter  sp.,  from  Lower  Ludlow,  Leintwardine, 
probably  belongs  to  this  genus. 


Order  2.     AN  ASPIDA.     Traquair.^ 


Tuberdes  only  on  the  head  region,  not  fused  into  plates  ;  the  calcifications  probably 
in  pari  with  bone  cells.     No  paired  appendages. 


Family  1.     Birkeniidae.     Traqiiair. 
Exteriml  ornamenf,  when  present,  tubercular.     Branchial  openings  a  series  of 


small  perforations  laterally  placed.     One  small  dorsal  fin  ;  tail  heterocercal.    Uppei 
Silurian. 

Birkenia,   Traq.    (Fig.    104).      Trunk   irregularly   covered  with   deepened 


Fig.  104. 

Birkenia  elegans,  Traq.     Restored  outline  in  side  view,  aboiit  nat. 
Upper  Silurian  ;  Lanarkshire  (after  Traquair).    d,  Dorsal  fin. 

scales ;  a  series  of  large  scutes  along  the  ventral  border. 
Upper  Silurian  ;  Lanarkshire. 


B.  elegans,  Traq. 


Fig.  105. 

Lasonitis  problematiciis,  Traq.     Restored  outline,  about  nat.  size.     Upper  Silurian  ;  Lanarkshire. 

r,  Postcephalic  rods  ;  r',  Chain  of  ossicles  ;  v.s,  Ventral  scntes  (after  Traquair). 

Lasanius,  Traq.  (Fig.  105).     Trunk  naked,  except  immediately  behind  the 

^   Traquair,  R.  JH.,  Keport  on  Fossil  Fishes  collected  by  the  Geological  Survey  of  Scotland  in  the 
Silurian  Rocks  of  the  south  of  Scotland  (Trans.  Roy.  Soc.  Edinb.  vol.  XXXIX.,  with  5  pls.),  1899. 


54  PISCES  CLASS I 

head,  where  rudiments  occiir  ;  a  series  of  large  scutes  along  the  ventral  border. 
L,  problematiciis,  Traq.     Upper  Silurian  ,  Lanarkshire. 

Family  2.     Euphaneropidae.      Smitli  Woodward. 

As  Birkeniidae,  but  no  series  of  branchial  openings.     Upper  Devonian. 

Euphanerops,  Sm.  Woodw.  JE.  longaevus,  Woodw.,  the  type  species,  is  the 
only  known  Ostracophore  which  displays  traces  of  the  axial  skeleton  of  the 
trunk.     Upper  Devonian  ;  Canada. 

Orders.     ASPIDOCBPHALI.     Brandt.i 

(Osteostracij  Ray  Lankester.) 

Exoskeleton  consisting  of  calcifications,  partly  with  bone  cells  ;  each  plate  in  the 
head  region  comprising  three  superposed  layers — an  inner  laminated  layer  with 
spindle-shaped  bone  cells;  a  relatively  thick  middle  layer  of  polygonal  cancellae  which 
may  be  more  or  less  solid  though  with  a  coarse  reticulation  of  large  vascular  canals  ; 
also  an  outer  hard  layer  of  vaso-dentine.  Orbits  dose  together.  No  paired 
appendages. 

Family  1.     Ateleaspidae.      Traqiiair. 

Head  shield  rounded  or  tapering  in  front,  abruptly  truncated  behind,  consisting 
of  loose  plates.  Body  covered  with  quadrangular  scales  which  are  deepened  on  the 
flank.     Tau  heterocercal.     Upper  Silurian. 

Ateleaspis,  Traq.,  from  the  Upper  Silurian  Passage  Beds  of  Seggieholm, 
Lanarkshire.  The  tubercles  of  the  head  region  are  fused  together  into  small 
plates.  The  genus  may  be  a  link  between  the  Heterostraci  and  Osteostraci, 
but  the  microscopical  structure  of  the  armour  agrees  with  that  of  the  latter. 

Family  2.     Oephalaspidae.     Agassiz. 

Head  shield  rounded  or  tapering  in  front,  abruptly  truncated  behind  ;  interorbital 
piece  firmly  fixed  ;  an  Ornament  of  rounded  or  stellate  tubercles.  Dermal  sense  organs 
leaving  no  impressions  on  the  exoskeleton.  Body  covered  with  quadrangular  scales, 
which  are  deepened  on  the  flank.  One  small  dorsal  fin  ;  tail  heterocercal.  Upper 
Silurian  to  Upper  Devonian. 

Cephalaspis,  Ag.  (Eucephalaspis,  Hemicyclaspis,  Zenaspis,  R.  Lank.),  (Figs. 


Fig.  106. 
Cephalaspis  lijelli,  Ag.     Lower  Old  Red  Sandstoiie  ;  Arbroath,  Scotland.    1/2  nat.  size  (after  Ray  Lankester). 

106,  107).    Postero-lateral  angles  of  shield  more  or  less  produced  into  pointed 

cornua,  external  to  a  small  flexible  Aap  on  each  side,  which  is  stiffened  by 

^  Huxley,  T.  H.,  On  Cephalaspis  and  Pteraspis  (Quar.  Jourii.  Geol.  Soc.  vols.  XII.,  XIV.,  XVII.), 
1856,  1858,  1%QI.— Lankester,  E.  R.,  The  Cephahispidae  (Monogr.  Palaeont.  Soc),  1867-69.— 
Schmidt,  Friedr.,  Verhandl.  k.  niss.  nüueral.  Ges.  1873  and  1886 ;  and  Bull.  Acad.  Imp.  Sei.  St. 
Petersb.  1894. — Rökan,  J.  V.,  Die  obersilurischen  Fische  von  Oesel  I;  (Meni.  Acad.  Imp.  Sei.  St. 
Petersb.,  ser.  7,  vol.  XXXVIII.),  1892  :  also  Bull.  Acad.  Imp.  1893. 


SUB-CLASS  II 


OSTRACODERMl 


55 


bony  plates,  and  seems  to  represent  an  operciilum.     Body  triangulär  in  trans- 

verse  section,  the  flanks  covered  with  three  lon^itudinal  series  of  deepened 

scales,  the  middle  series  deepest.     Ventral  scales  small.     Dorsal  fin  triangulär, 

at  the  base  of  the  heterocercal  tail ;  membrane  of  dorsal  and  anal  fins  stiffened 

with   very   small    calcifications    which    are 

arranged  in  parallel  rows  simulating  rays. 

C.  lyelli,  Ag.   (Fig.  106),  from  Lower  Öld 

Red    Sandstone  of  Scotland   and  west  of 

England.      C.  magnifica,  Traq.,  the  largest 

known  species,  with  shield  measuring  0*22 

m.     across,     from     Caithness     Flagstones. 

Other   species    from    Upper    Silurian    and 

Lower  Devonian  of  Scotland,  England,  and 

Canada.    One  species (6'.  laticeps,  Traq.),  from 

Upper  Devonian,  Scaumenac  Bay,  Canada. 

Eukemspis,  Lank.  (Sderodus,  Pledrodus^ 
Ag.).  As  above,  but  posterior  cornua 
excessively  elongated,  and  a  row  of  twelve 
large  "marginal  cells  "  around  the  rim  in 
front.  The  detached  denticulated  cornua 
were  originally  mistaken  for  jaws.  E. 
pustulijera,  Ag.  sp.,  from  Upper  Silurian, 
Herefordshire. 

Thyestes,  Eichw.  {Auchenaspis,  Egerton). 
three  or  four  series  of  dorso-lateral  scales  fused  into  a  continuous  plate 
immediately  behind  it.  Body  depressed,  ovoid  in  transverse  section.  Known 
species  very  small.  T.  verrucosus,  Eichw.,  from  Upper  Silurian,  Isle  of  Oesel. 
So-called  Auchenaspis  from  Upper  Silurian  and  Lower  Old  Red  Sandstone 
Passage  Beds  of  Herefordshire. 


Fig.  107. 

Head  shield  of  Ceplmlaspis  lyelli,  Ag.  Lower 
Old  Red  Saiidstone ;  Herefordshire  (after  Lan- 
kester).     1/2. 


Head  shield  as  in  Cephalaspis,  but 


Family  3.     Tremataspidae.     Smith  Woodward. 


Head  shield  rounded  or  tapering  in  front,  fused  with  the  dorsal  hody-shield,  which  is 
truncated  behind;  interorbital  piece  notfixed.    Upper  Silurian  and  Lower  Devonian. 

Tremataspis,  Schmidt.  Dorsal  shield  rounded  in  front,  gently  arched, 
without  cornua ;  ventral  shield  simple.  External  surface  covered  with 
punctate  ganoine,  the  punctations  often  arranged  in  reticulating  lines ; 
superficial  tuberculations  almost  or  entirely  absent.  Two  pairs  of  large 
openings  laterally  placed  in  the  anterior  half  of  the  dorsal  shield  are  in- 
terpreted  by  Smith  Wood  ward  as  occurring  in  the  roof  of  the  branchial 
Chamber,  covered  over  during  life  but  ensuring  flexibility.  Ventral  aspect 
immediately  behind  the  position  of  the  mouth  covered  with  a  number  of 
symmetrically  arranged  polygonal  plates,  between  which  and  the  great  ventral 
plate  of  the  trunk  is  a  transverse  series  of  nine  small  openings  on  each  side, 
probably  of  branchial  nature.  Tail  covered  with  rhombic  and  polygonal  scales, 
which  have  been  named  Dasylepis,  Dictyolepis,  Melittomalepis,  and  Stigmolepis 
by  Pander.  T.  schrenki,  Pander  sp.,  and  other  species  in  the  Upper  Silurian, 
Isle  of  Oesel,  Baltic  Sea. 

Didymaspis,  Lankester.  D.  grimlrodi,  Lank.,  from  Lower  Old  Red  Sand- 
stone, Ledbury,  Herefordshire. 


56 


PISCES 


CLASS I 


Order  4.     ANTIARCHA.     Cope.i 

Dermal  armour  fused  into  large  plates  on  the  head  and  abdominal  region.  Exo- 
sJceleton  consisting  of  calcifications  with  h(me  corpusdes,  and  invested  with  a  more  or 
less  continuous  layer  of  ganoine.  Dermal  sense  organs  occupijing  open  grooves  on  the 
exoskeleton.  Dorsal  and  ventral  shields  consisting  of  several  symmetrically  arranged 
pieces,  and  the  head  articulated  loith  the  trunh.  Orbits  close  together.  Ä  pair  of 
paddle-like  pectoral  appendages,  invested  in  dermal  plates,  articulated  with  the 
anterior  ventro-lateral  plates  of  the  trunh.     Median  fins  not  continuous. 

The  bony  plates  of  the  Antiarcha  consist  of  three  layers  with  numerous 
bone  cells,  the  middle  layer  traversed  by  large  canals  and  lacunae,  while  the 
outer  and  inner  layers  exhibit  a  more  compact  texture. 


Family  1.     Asterolepidae.     Traquair. 

Exoskeleton  robust  and  tuberculated.  Dorsal  and  ventral  shields  of  trunh  firmly 
y  the  lateral  plates.  Inter orbital  piece  not  ßxed.  A  fair  of  paddle-lihe 
appendages,  completely  encased  in  dermal  plates,  movably  articulated  by  a  complex 
Joint  with  the  anterior  ventro-lateral  plates  of  the  trunh.  Tail  heterocercal,  and  one 
small  dorsal  fin.     Devonian. 

Pterichthys,  Ag.  (Pterichthyodes,  Bleeker),  (Figs.  108,  109).     From  3  to  20 


Fig.  108. 
Pterichthys  milleri,  Ag.     Restoration  from  above  {A),  below  (B),  and  in  side  view  (C).     Lower  Cid  Red  Sand- 
stone ;  Scotlaud.     ap,  Pectoral  api)endages  ;  j,  Articulation  ;  op,  Operculuni ;  orb,  Orbit  (after  Traquair). 

cm.  in  length,  with  a  small  head,  which  is  rounded  in  front,  a  broad  and  deep 
trunk  flattened  below,  and  a  scaly  tail.     The  upper  surface  of  the  head  is 

^  Pander,  C.  H.,  Die  Placodermen  des  devonischen '«Systems.     St.  Petersburg,  1857. — Traquair, 
R.  H.,  Ann.  Mag.  Nat.  Hist.  ser.  6,  vol.  II.  1888  ;  and'Mon.  Palaeont.  Soc,  1894. 


SUB-CLASS  II 


OSTRACODERMI 


57 


covered  with  four  pairs  of  lateral  plates  and  four  unpaired  median  plates, 
which  are  united  by  straight  sutures.  On  the  lower  surface  the  cleft  for  the 
mouth  is  bounded  in  front  by  a  pair  of  transversely  elongated  plates,  which 
are  sometimes  supposed  to  represent  the  upper  jaw.  Behind  the  cleft  a  pair 
of  smaller  plates  occurs  fixed  to  the  front  of  the  abdominal  shield.  The 
trunk  is  armoured  above  by  two 
large  median  and  two  pairs  of 
lateral  plates  ;  on  its  ventral  surface 
four  large  ventro-laterals  Surround 
a  small  rhombic  ventro  -  median 
element.  The  ventro-laterals  are 
sharply  bent  upwards  and  outwards 
near  their  lateral  border  to  take 
part  in  covering  the  flank.  Both 
the  head  plates  and  the  dorso-lateral 
plates  of  the  trunk  are  traversed  by 
sensory  grooves,  those  of  the  head 
being  united  by  two  parallel  com- 
missures.  The  two  hinder  lateral 
plates  of  the  head  and  the  adjoin- 
ing  body  plates  have  bevelled  edges, 
so  that  the  former  overlap  the  latter. 
The  anterior  median  dorsal  plate  of 
the  trunk  somewhat  overlaps  the 
lateral  plates,  and  is  overlapped 
behind  by  the  border  both  of  the 
posterior  dorso-laterals  and  of  the 
posterior  median  dorsal  plate.  The 
orbits  occur  at  the  two  ends  of  a 
transverse  cleft  on  the  upper  sur- 
face of  the  head,  and  are  separated 
by  a  quadrangular  median  plate  (os 
duhium  or  os  pineale),  which  exhibits 
a  small  deep  pit  on  its  inner  face. 
The     two    anterior    ventro  -  lateral 


Fig.  100 

Pterichthys  miUcri,  Ag.  Lower  Cid  Red  Sandstone ; 
Gamrie,  Scotland.  A,  Specimen  in  nodule,  1/2  nat.  size. 
B,  Scale  enlarged  (after  Egerton). 


plates  of  the  trunk  are  provided  in  front  with  an  articular  hollow  on  each 
side,  in  which  are  fixed  the  armoured  paddle-shaped  pectoral  appendages.  The 
latter  do  not  reach  the  hinder  end  of  the  body  shield,  and  exhibit  one  trans- 
verse articulation  (j)  at  about  their  middle.  The  tail  is  covered  with  thin, 
rounded,  or  six-sided,  overlapping  scales.  The  single  dorsal  fin  is  small. 
The  tail  is  heterocercal,  with  large  fulcral  scales  on  its  upper  border,  and  the 
fin  membrane  confined  to  the  lower  lobe.  P.  milleri,  Ag.,  and  other  species 
represented  by  complete  but  usually  ill-preserved  examples  in  the  Lower  Old 
Red  Sandstone  of  Scotland.  Fragments  in  the  Middle  Devonian  of  the  Eifel. 
Asterolepis,  Eichw.  (Narcodes,  Odontacanthus,  Ag.).  As  Pterichthys,  but  often 
larger,  and  the  anterior  median  dorsal  plate  overlaps  both  the  anterior  dorso- 
laterals  and  the  posterior  dorso-lateral  plates.  Chiefly  represented  by  detached 
plates  in  the  Devonian  of  N.-W.  Russia  and  in  the  Upper  Old  Red  Sandstone 
of  Scotland.  More  doubtful  fragments  from  the  Devonian  of  Bohemia,  the 
Eifel,  East  Greenland,  and  Australia. 


58  PISCES  CLASSI 

Microbrachius,  Traquair.  M.  dicki,  Traquair,  from  Lower  Old  Red  Sandstone, 
Caithness  and  Orkney. 

Bothriolepis,  Eichw.  (Pamphradus,  Placothorax,  Homothorax,  Glyptosteus,  Ag.). 
Armour  nearly  as  in  Pterichthys,  but  the  pectoral  appendages  reaching  back- 
wards  beyond  the  body  sbield,  and  the  hinder  mucous  canal  commissure  on  the 
head  V-shaped.  Tail  unknown,  probably  not  scaly.  An  Upper  Devonian 
genus,  known  from  N.-W.  Russia,  Scotland,  England,  Canada,  and  Penn- 
sylvania. Remarkably  fine  examples  of  the  armour  of  B.  canadensis,  Whit- 
eaves,  0'20  m.  in  length,  from  Scaumenac  Bay,  Province  of  Quebec,  Canada. 

?  Ceraspis,  Schlüter  ;  Belemnacanfhus,  Eastm.     Middle  Devonian  ;  Eifel. 

Incertae  Sedis. 

Macropetalichthys,  Norwood  and  Owen.  Plates  of  cranial  shield  fused 
together  in  adult ;  orbits  completely  enclosed  in  the  shield ;  sensory  canals 
forming  large  tubulär  excavations  in  the  bone,  opening  at  the  external  surface 
by  a  continuous  narrow  slit  or  a  series  of  pores.  Jaws  and  other  parts  of 
the  skeleton  unknown.  Middle  Devonian  (Corniferous  Limestone) ;  Ü.S.A. 
Also  Upper  and  Lower  Devonian  of  Eifel. 

Asterosteus,  Newb.  Known  only  by  the  flattened  and  elongated  cranial 
shield,  which  has  the  constituent  elements  fused  in  the  adult.  Orbits  placed 
far  forwards  and  forming  broad  notches.     Corniferous  Limestone  ;  Ohio. 


Sub-Class  3.     ARTHRODIRA,     Smith  Woodward. 

Early  Palaeozoic  fishes  with  persistent  notochord,  and  endoskeleton  superßcially 
calcißed.  Head  and  trunk  armoured  with  symmeirically  arranged  hony  plates,  some  of 
which  are  traversed  hy  sensory  grooves ;  head  shield  movahly  articidated  by  a  pair  of 
ginglymoid  joints  with  the  body  shield.     Paired  fins  rudimentary  or  abseilt. 

The  Coccostean  fishes  were  originally  grouped  by  M'Coy  with  Asterolepis 
and  Pterichthys  in  the  "family  Placodermi,"  and  they  are  included  by  Pander 
in  his  "  Placodermen."  The  resemblance  between  their  jaws  and  those  of  the 
existing  Dipnoi  was  pointed  out  by  Newberry  and  Traquair ;  and  they  were 
provisionally  regarded  as  an  order  of  Dipnoi  by  Smith  Woodward.  Dean 
elevates  them  to  the  rank  of  an  independent  class,  removing  them  from  Pisces 
on  the  ground  that  their  jaw  elements  are  merely  dermal  ossifications,  and 
are  not  articulated  with  the  skull. 

Family  1.     Coccosteidae.     Smith  Woodward.^ 

Head'  shield  comprising  three  pairs  of  lateral  plates,  one  large  median  occipital 
plate,  and  two  symmetrical  pairs  of  plates  in  front  of  the  latter,  the  foremost  pair 
surrounding  one  or  two  small  median  plates.  Orbits  lateral ;  nasal  opening s  small 
and  far  forwards  ;  dental  plates  movable,  toothless,  or  provided  with  cusps  of  dentine. 
Trunk  with  a  large  median  dorsal  plate  often  bearing  a  longitudinal  median  keel  on 
its  linder  surface  ;  also  two  pairs  of  lateral  plates,  the  anterior  with  a  pair  of  articular 

^  Traquair,  R.  H.,  On  the  Structure  of  Coccosteus  decipiens,  Ag.  (Ami.  Mag.  Nat.  Hist.  ser,  6, 
vol.  V.  p.  125),  1890.— i>eaw,  B.,  Palaeontological  Notes  (xMem.  N.  Y.  Acad.  Sei.  vol.  IL  pt.  3), 
1901. — Eastnum,  C.  R.,  Some  new  points  in  Dinichthyid  Osteology  (Anier.  Nat.  vol.  XXXII.  p. 

747),  1898. 


SUB-CLASS  III 


ARTHRODIEA 


59 


processes  for  union  with  the  head  shield.  Ventral  hody  armowr  comprising  two  or 
three  pairs  of  lateral  plates  and  two  small  unpaired  median  plates.  All  external 
plates  more  or  less  tuberculated.  Dorsal  fin  small  ;  anal  fin  unknown ;  tail  diphy- 
cercal  or  heterocercal.     Devonian. 

Coccosteus,  Ag.  (Liognathus,  Newb.),  (Figs.  110,  111).  Head  and  truiik 
broad,  the  dermal  plates  covered  with  stellate  tubercles.  Cranial  plates  united 
by  sutures,  not  fused.  Orbit  forming  a  notch  in  the  anterior  part  of  the 
lateral  border  of  the  shield ;  a  bony  sclerotic  ring  present.  Besides  the 
*'maxilla"  and  "premaxilla,"  one  or  two  inner  pairs  of  dentigerous  bones  also 


Coccosteus  decqnens,  Ag. 


Fig.  110. 

lieft  antero-dorso-lateral  plate  of  trank,  inner  {A),  and  outer  {B),  aspects. 
liOwer  Cid  Red  Sandstone  ;  Scotland. 


L.,„.„ ,„„...„..... 

^^)f  transversely  elongated  slender  plates,  perhaps  representing  the  pectoral 
arch  ;  a  small  pectoral  spine,  but  never  any  traces  of  pectoral  fins  observed. 
Ribs  absent.  Dorsal  fin  short-based.  Tail  destitute  of  scales.  Nearly  com- 
plete  but  imperfectly  preserved  skeletons  of  C.  dedpiens,  Ag.  (Figs.  110,  111), 
occur   in  the  Lower  Old  Red  Sandstone  of  Scotland.     Fragments  of   other 


Fig.  111. 


Ci)Cco.<teuti  ilecipieiis,  Ag.     Restoration,  i/^-     Lower  Old  Red  Sandstone  ;  Scotland  (after  Smith  Woodward). 

species  in  the  Upper  Devonian  of  England,  Ireland,  Germany,  Russia,  and 
Canada.     Also  from  Corniferous  Limestone  (Middle  Devonian),  Ohio,  U.S.A. 

Brach/dirus,  v.  Koenen.  Considered  by  von  Koenen  to  differ  from  Cocco- 
steus in  the  presence  of  a  pair  of  hollow  spines  which  perhaps  represent 
pectoral  fins.      Upper  Devonian  ;  Bicken,  Nassau. 

Phlt/cfaenaspis,  Traquair.  Lower  Devonian ;  Canada,  west  of  England,  and 
Russian  Poland.     Acanthaspis,  Newb.     Lower  and  Middle  Devonian  ;  U.S.A. 

Chelyophorus,  Ag.      Upper  Devonian  ;  Russia. 

Dinichthys,  Newberry  (Fig.  112).  Yery  large,  the  head  sometimes 
measuring  1  m.  in  length  and  0*7  m.  in  breadth.  Median  occipital  plate  sub- 
triangular  with  prominent  median  process  behind ;  lateral  occipital  plates  with 
very  deep  articular  sockets  for  the  reception  of  the  process  on  the  antero-dorso- 
lateral  plates  of  the  body  shield.     Orbit  forming  a  notch  as  in  Coccosteus.     Pre- 


60 


PISCES 


CLASS  I 


maxillae  and  symphysial  end  of  mandibular  bones  with  a  pair  of  stout  cusps  or 
beaks,  and  the  trenchant  margin  behind  these  sometimes  toothed.  Median 
dorsal  plate  very  thick,  often  over  0*6  m.  long  and  broad.     Antero-dorso-lateral 


Fig.  112. 

Dinichthys  lierzeri,  Newberry.     Diagramm atic  front  view  of  upper  and  lower  jaws,  i/g. 
Upper  Devonian  (Huron  Shales) ;  Delaware,  Ohio  (after  Newberry). 

plate  overlapped  by  the  large  "  clavicular."    Several  species  in  the  Middle  and 
Upper  Devonian  of  Iowa,  Wisconsin,  Ohio,  New  York,  and  Canada ;  others 

in    the    Devonian    of    the    Eifel, 
Bohemia,  and  Russia. 

Titanichthys,  Newb.  Cranial 
shield  very  large,  thin  and 
flattened,  arrangement  of  plates 
closely  similar  to  that  of  Din- 
ichthys. Jaw  elements  much 
reduced,  edentulous,  probably 
sheathed  in  hörn.  Dorso-median 
without  an  inferior  longitudinal 
keel,  deeply  emarginate  in  front. 
Antero-  and  postero-dorso-laterals 
fused,  articulated  to  the  cranial 
shield  by  a  long  hinge,  and  over- 
lapped by  the  large  claviculars. 
T.  agassizi,  N.,  has  a  horizontal 
expanse  of  1*9  m.  across  head- 
shield  and  claviculars.  Cleveland 
Shale  (Upper  Devonian) ;  Ohio. 

Homosteus^  Asmuss.  (Fig.  113). 
Very  large  fishes,  broad  and  de- 
pressed.  Orbits  completely  en- 
closed  in  the  head  shield ;  jaws 
slender  and  toothless.  Median 
occipital    plate    antero -posteriorly 


Fig.  113. 


Homosteus  milleri,  Traq.  Cranial  and  dorsal  shield,  i/g  nat. 
size.  Lower  Cid  Red  Sandstone ;  Caitlmess.  A,  B,  C,  Un- 
determined  bones  ;  adl.  Anterior  dorso-lateral ;  ae,  Ethmoid ; 
c.  Central ;  eo,  External  occipital ;  vi.  Marginal ;  md,  Median 

dorsal ;  mo,  Median  occipital ;  o,  Orbit ;  -pdl.  Posterior  dorso-      ,  ^     ,  , .  ,  ^      ^    ,         r 

lateral;  po,  Preorbital ;  pto,  Postorbital.  Pineal  plate  elongated ;  median  dorsal  plate  Ol 
behind ''ethmoid  "  or  rostral.  The  double  lines  indicate  the  f}ip  f^nnlr  hrnn rl Pr  fVinn  Inner  TT 
course  of  the  sensory  grooves  (after  Traquair).  LUetlUIlK    Uiuauei   tuan    iOIlü.       xi. 


the  trunk  broader  than  long. 

milleri,  Traq.,  from  Lower  Old  Red 

Other  species  in   Upper  Devonian  of 


Sandstone,   Caithness  and   Orkney. 
Livonia. 

Heterosteus,  Asmuss.     Nearly  resembling  Homosteus,  but  larger,  and  anterior 
dorso-lateral  body  plates  with  an  enormous  anteriorly  directed  process  which 


SUB-CLASS  IV  DIPNOI  61 

clasps  the  head  shield  on  each  side.  H.  asmussi,  Ag.  sp.,  common  in  Upper 
Devonian  of  Livonia,  but  known  only  by  the  massive  detached  plates. 

Aspidichthys,  Glyptaspis,  Trachosteus,  Newberry ;  Anomalichthys,  v.  Koenen  ; 
Asteroplax,  Sm.  Woodw.     Devonian. 

Mylostoma,  Diplognathus,  Newberry  ;  Selenosteus,  Stenosteus,  Dean.  Upper 
Devonian  (Cleveland  Shale) ;  Ohio. 

Most  of  the  genera  enumerated  on  this  and  the  preceding  page  are 
regarded  by  Dean  and  others  as  types  of  distinct  families. 

Sub-Class  4.     DIPNOI,  Müller.'     Lung-fishes. 

Skeleton  partially  ossified,  with  numerous  well-developed  memhrane  bones.  Pterygo- 
quadrate  arcade  completely  and  immovably  fused  with  the  cranium  ;  gilt  clefts  feehly 
separated,  opening  into  a  cavity  covered  with  a  hony  operculum.  Faired  fins  paddle- 
Uke,  with  a  long,  segmented  cartilaginous  axis  (archipterygium  of  Gegenbaur) ;  tail 
diphycercal  or  heterocercal.  In  the  living  forms — optic  nerves  not  decussating,  but 
forming  a  chiasma,  bulbus  arteriosus  of  the  heart  with  numerous  valves,  intestine  with 
a  Spiral  valve,  and  air-bladder  lung-liJce. 

The  internal  skeleton  of  the  Dipnoi  is  chiefly  cartilaginous,  but  the  upper 
and  lower  vertebral  arches,  the  ribs  and  fin-supports,  all  exhibit  some  tendency 
towards  ossification. 

The  Dipnoi  differ  so  much  from  all  fishes,  in  the  modification  of  the  air- 
bladder  into  a  Single  or  double  elongated  sac  with  numerous  cellular  Spaces, 
which  serves  as  a  lung  and  is  connected  by  a  short  tube  with  the  anterior 
wall  of  the  gullet ;  moreover,  in  the  peculiar  characters  in  the  structure  of 
the  heart,  in  the  presence  of  internal  narial  openings,  and  in  the  possession 
of  the  faculty  of  existing  for  a  considerable  period  out  of  water,  that  they 
have  often  been  regarded  as  fish-like  Amphibia  or  scaly  Sirens.  The  discovery 
of  the  "Barramunda"  (Ceratodus  forsteri)  in  the  rivers  of  Queensland  confirmed 
the  idea  of  their  relationship  to  the  Palaeozoic  Crossopterygians  previously 
suggested  by  Huxley.  Nevertheless,  they  are  distinguished  from  these  and 
from  all  other  Ganoids  and  Teleosteans  by  the  autostylic  arrangement  of  the 
jaws.     They  are  divided  into  the  two  Orders  of  Ctenodipterini  and  Sirenoidei. 

Order  1.     CTENODIPTERINI.     Pander. 

Cranial  roof  bones  small  and  numerous,  Rays  of  median  fins  very  fine,  much 
more  numerous  than  their  supports,  which  are  directly  apposed  to  the  vertebral  arches. 

Family  1.     Uronemidae.     Traquair. 

Upper  dentition  comprising  a  düster  of  small,  Munt,  conical  denticles  on  the 
palatine  bones ;  lower  dentition  of  similar  denticles  on  the  splenial.  Median  fins 
continuous  and  tail  diphycercal.     Lower  Carboniferous  to  Lower  Permian. 

1  Günther,  A.,  Description  of  Ceratodus  (Phil.  Trans,  vol.  CLXI.),  1871-72.— Hnxlei/,  T.  H., 
Proc.  Zool.  Soc.  1876,  p.  24. — Miall,  L.  C,  Monograph  of  the  Sireuoid  and  Crossopterygian  Ganoids 
(Palaeont.  Soc),  1878. — Pander,  C.  II.,  Ueber  die  Ctenodipterinen,  etc.,  des  devonischen  Systems. 
St.  Petersburg,  1858.  —  Traquair,  R.  H.,  On  the  genera  Bipterus,  Palaedaphus,  Holodus,  and 
Gheirodus  (Ann.  Mag.  Nat.  Hist.  ser.  4,  vol.  XVII.),  1878  (also  ibid.  ser.  5,  vol.  II.).— Teller,  F., 
Ueber  Ceratodus  sturi  (Abh.  k.k.  geol.  Reichsanst.  Wien.  vol.  XV.),  1891. — Zittel,  K.  A.  von,  Ueber 
Ceratodus  (Sitzungsb.  k.  bay.  Akad,  Wiss,,  math.-phys.  Cl.),  1886. 


PISCES 


CLASS  I 


Uronemus,  Ag.  (Ganopristodus,  Traq.).  Body  laterally  compressed,  with 
small  and  very  thin  scales,  which  are  faintly  striated.  Paired  fins  acutely 
lobate.  Dorsal  fin  arising  shortly  behind  the  head.  U.  lobatus,  Traq.,  from 
Lower  Carboniferous  (Calciferous  Sandstones),  Burdiehouse,  near  Edinburgh. 

Conchopoma,  Kner.     Lower  Permian  ;  Ehenish  Prussia. 


Family  2.     Ctenodontidae.     Traqiiair. 


on  the 
Jugular 


Ä  pair  of  dental  plates  on  the  palatine  bones,  and  an  opposing 
splenials  ;  these  plates  usually  retaining  traces  of  their  component  denticles 
plates  usuülly  present.     Tail  diphycercal  or  heterocercal. 

Dipterus,  Sedgw.  and  Murch.  (Catopterus,  Polyphradus,  Ag.),  (Figs.  114, 
115).  Small  fishes.  Bony  plates  of  head  covered  with  punctate  ganoine, 
but  cranium  apparently  quite  cartilaginous.      Base  of  cranium  covered  with  a 


Dipterus  valcticiennesi,  Sedgw.  and  Murch.     Restoration,  i/s  »at.  size. 
Lower  Cid  Red  Sandstoiie  ;  Baniiiskirk,  Orkney  (after  Pander). 

broad,  rhombic  parasphenoid  (PSph),  which  is  flanked  on  either  side  by  a 
pterygo- palatine  (P)  extending  forwards  into  a  triangulär  pointed  plate, 
which  serves  as  base  for  a  large  triangulär  tooth  (d)  bearing  tuberculated 
radiating  ridges.  The  two  palatine  bones  meet  in 
the  middle  in  a  straight  line.  The  mandible  is  com- 
pletely  ossified,  with  a  single,  large  dental  plate  on 


PSph 


Dipterus  valencienyiesi,  Sedgw.  and  M.  Lower  Old  Red  Sandstone  ;  Banniskitk.  A,  Roof  of  skull.  li,  In 
perfect  palate  (PSph,  Parasplienoid ;  P,  Pterygo  -  palatine,  accidentally  divided  into  two  pieces  behind  by 
broken  Ime  ;  d,  Palatine  tooth).     C,  Imperfect  mandible  with  tooth  (d),  after  Pander). 


the  splenial  of  each  side,  and  its  tuberculated  ridges  radiating  fan-like  froni 


8UB-CLASS  IV 


DIPNOI 


63 


within  outwards.  Two  pairs  of  jugular  plates.  Paired  fins  acutely  lobate, 
the  pelvic  pair  remote  and  opposed  to  the  anterior  of  the  two  dorsal  fins ; 
anal  fin  opposite  the  posterior  dorsal;  tail  heterocercal.  Trunk  and  fins 
covered  with  thick,  deeply  overlapping  scales,  which  are  nearly  rhombic  in 
their  exposed  portion  and  invested  with  punctate  ganoine.  Complete,  but 
mostly  flattened  and  distorted  examples  of  Dipterus  are  not  uncommon  in  the 
Lower  Old  Eed  Sandstone  of  Northern 
Scotland.  Dental  plates  very  abundant 
in  Middle  and  Upper  Devonian  of  central 
and  eastern  United  States. 

Scaumenacia,  Traq.  Upper  Devonian  ; 
Canada. 

Phaneropleuron,  Huxley  (Fig.  117). 
Upper  dental  plates  triangulär,  with 
straight  and  crenulated  radiating  ridges. 
Long  dorsal  fin  continuous  with  the 
caudal,  but  small  anal  fin  separate. 
Scales  very  thin  and  cycloid,  marked 
with  delicate  radiating  Striae.  P.  ander- 
soni,  Huxl.,  known  by  well  -  preserved 
specimens  from  Upper  Old  Red  Sand- 
stone, Fifeshire. 

Falaedaphus,  van  Beneden  {Heliodus, 
Newb.),  (Fig.  118).  Only  known  by 
mandible  and  detached  dental  plates.     In 

P.  insiqilis,  van  Ben.  and  de  Koninck,  each     Newsham,   Northiuniierland   (after   Hancock   and 
,  ^       ,    ^        t    ,  .  /^  -1  cf  Attliey).    Oral  surface  of  teetli  really  coiicave. 

lower    dental    piate,   measuring   0"17   m. 

in    length,  bears    four   smooth,  obtuse   radiating  ridges.     Upper  Devonian ; 

Belgium  and  Pennsylvania. 

ConchodvjS,  M'Coy  ;  Synthetodus,  Eastman.     Devonian. 

Ctenodus,  Ag.  (Fig.  116).     Hinder  border  of  cranial  roof  with  one  median 
occipital  plate,  with  a  pair  of  plates  immediately  adjoining  in  front.     Dental 


Fig.  116. 

Ctenodus  tabercnlatus,  Atthey. 


with  palatal  teeth, 


Pterygo-palati 
l-i  nat.  size.     Goal  Measure>^ 


Fio.  117. 

Phani'ropletiron  andersoni,  Huxley.     Upper  Old  Red  Sandstoue  ;  Dura  Den,  Fifeshire. 

1/:!  nat.  size  (after  Page). 


plates  with   numerous   tuberculated  or  crenulated   radiating  ridges.     Dorsal 


64 


PISCES 


CLASS  I 


and  anal  fins  continuous  with  the  caudal,  which  is  diphycercal ;  scales  very 
large  and  thin,  without  a  ganoine  layer,  almost  quadrate  in  shape,  but  with 
^j  rounded  angles ;  niarked  more  or  less 

distinctly  with  reticulations,  as  in 
Ceratodus.  Dental  plates  common 
in  the  Carboniferous  of  Europe 
and  North  America ;  fine  portions 
of  skeleton  in  the  English  Goal 
Measures. 

Sagenodus,  Owen  (Megapleuron, 
Gaudry ;  Ptyonodus,  Cope).  As 
Ctenodus,  but  dental  plates  with  fewer 
ridges,  and  median  occipital  plate 
with  another  unpaired  plate  im- 
mediately  in  front  of  it.  Scales  and 
dental  plates  common  in  the  Carboni- 
ferous and  Lower  Permian  of  Europe 
^^°"  ^^^'  ^    .    ,     and  North  America  :  fine  skeletons  in 

Falaedaphus  insiqnis,  van  ßeneden  and  de  Koninck.  , ,        t-  -p.  •  j?    -r»    i  •  i 

Ijnperfect  niandibie,  1/4  nat-  size.     Devonian ;  Liege,  the    Lower    rermian    Ol     bonemia    and 

c,  Tooth;  d,  Dentary ;  op,  Splenial ;  y,  Lateral  fossa  ■^„„„„q 

(after  Traquair).  ^  ^  ante. 


Order  2.     SIRENOIDEI. 

Cranial  roof  hones  large  and  few.     Rays  of  median  fins  very  fine,  much  more 
niimerous  than  their  Supports,  which  are  directly  apposed  to  the  vertebral  arches. 


Family  1.     Lepidosirenidae. 

A  pair  of  dental  plates  on  the  palatine  hones,  and  an  opposing  pair  on  the 
also  a  pair  of  small  cutting  teeth  on  the  vomer.  Jugular  plates  absent. 
Median  fin  continuous,  and  tail  diphycercal.  Body  covered  with  thin,  elastic,  cycloid 
scales  without  a  hony  hasis.     Triassic  to  Recent. 

Of  the  three  genera  ref erable  to  this  family,  Lepidosiren  lives  in  the  tropical 
swamps  of  South  America,  Protopterus  in  those  of  Africa,  and  Ceratodus  in  the 
rivers  of  Queensland. 

Ceratodus,  Ag.  (Fig.  119),  is  covered  with  large,  thin  cycloid  scales;  the 
dorsal  and  anal  fins  are  continuous  with  the  diphycercal  caudal.  The  pectoral 
and  pelvic  fins  are  fringed  with  membrane  stifFened  by  fine  rays.  The  upper 
vertebral  arches,  spinous  processes,  ribs,  and  fin  supports  are  encased  in  thin 
bony  sheaths.  The  flattened  roof  of  the  skull  consists  of  two  large  median 
plates,  one  behind  the  other,  and  two  pairs  of  lateral  plates.  On  the  lower 
side  of  the  chondrocranium  there  occurs  the  long  parasphenoid  {PSph),  with 
its  rhombic  anterior  expansion  flanked  on  either  side  by  the  pterygo-palatines 
{Pt).  The  latter  bones  meet  in  a  median  suture  in  front,  and  each  bears  a 
large  triangulär  dental  plate  {d),  with  radiating  ridges.  The  vomerine  carti- 
lage  {Vo)  bears  a  pair  of  sharp,  chisel-shaped  teeth  {d').  On  the  splenial  of 
each  ramus  of  the  mandible  there  is  also  a  dental  plate  with  deep,  radiating 
ridges.  The  opercula,  sub-opercula,  hyoid  bones,  and  branchial  arches  are 
ossified  3  the  quadrate  remains  cartilaginous. 

In  the  living  Ceratodus  (Epiceratodus,  Teller),  the  upper  and  lower  dental 


SUß-CLASS  V 


GANOIDEI 


65 


plates  bear  six  ridges  radiatiiig  outwards.  The  corresponding  plates  occurring 
in  the  Trias,  namely,  in  the  bone  beds  of  the  Muschelkalk,  Lettenkohle,  and 
Rhaetic,  are  distinguished  by  their  larger  size  and  a  different  niimber  of  ridges. 
As  a  rule,  the  upper  dental  plates  exhibit  five,  the  lower  ones  only  four 
radiating    ridges.       The    oldest    known    species    {C.   arenaceus^    Quenst.)    was 


I 


Fig.  119. 

Ceratodus  forsten,  Krefft.  Lateral  aspect  of  fish  (A),  base  of  skull  {£),  and  mandible  (C).  Recent ;  Queens- 
land. Br,  Brancliial  cavity  ;  c,  Foremost  rib  ;  d,  Teeth  ;  na,  Nasal  openings  ;  PSpk,  Parasphenoid  ;  Pt,  Pterygo- 
palatine  ;  Qu,  Quadrate  ;  Vo,  Voiiier  (after  Günther).  D,  Ceratodios  kaupi,  Ag.  Mandibular  tooth  on  bony  base, 
Vs  nat.  size.     Lettenkohle  ;  Hoheneck,  near  Ludwigsburg. 

obtained  from  the  Bunter  Sandstone  of  Würternberg ;  the  latest,  which  are 
the  smallest,  are  discovered  in  Europe  in  the  Bathonian  of  Stonesfield  and 
Northampton,  England,  in  North  America  in  the  Upper  Jurassic  of  Colorado. 
Other  examples  occur  in  the  Kota-Maleri  beds  of  India,  in  the  Karoo 
Formation  of  South  Africa,  and  in  later  deposits  in  Patagonia.  A  well- 
preserved  skull  of  C.  sturi  has  been  described  by  Teller  from  the  Upper 
Keuper  of  Polzberg,  near  Lunz,  in  Lower  Austria. 


Sub-Class  5.      GANOIDEI.     Agassiz.^     Enamel-scaled  Fishes. 

Trunk  and  tau  usually  covered  with  ganoid  scales,  rarehj  naked  or  with  hony 
j^lates.  Skull  covered  with  dermal  bones,  or  completely  ossified ;  pterygo-quadrate 
arcade  movably  articulated  with  the  cranium  (hyostylic) ;  gilt  clefts  feebly  separated, 
opening  into  a  cavity  covered  with  a  hojiy  operculum.  Vertebral  column  cartilaginous, 
or  with  various  degrees  of  ossification.     Fin  rays  articulated,  and  fulcra  usually 

1  Cope,  E.  D.,  Trans.  Amer.  Phil.  Soc.  vol.  XIV.  1871,  p.  445  ;  and  Amer.  Nat.  vols.  XIX., 
XX.,  XXL,  XXIII.  (1885-89).— /^m-%,  T.  H.,  Preliminary  Essay  upon  the  Systematic  Arrange- 
ment of  the  Fishes  of  the  Devonian  Epoch  (Meni.  Geol.  Surv.  dec.  X.),  1861. — Kner,  B.,  Betrach 
tungen  über  die  Ganoiden  als  natürliche  Ordnung  (Sitzungsb.  k.  Akad.  Wiss.  Wien,  math.-naturw. 
Ci.  vol.  LIV.),  1866.  —  Liitken,  Chr.,  Ueber  die  Begrenzung  und  Eintheilung  der  Ganoiden 
(Palaeontogr.  vol.  XXII.),  1868. — Malier,  Joh.,  Ueber  den  Bau  und  die 'Grenzen  der  Ganoiden 
(Abhandl.  k.  Akad.  Wiss.  Berlin,  1834),  l^Q.—Traquair,  R.  II.,  The  Ganoid  Fishes  of  the  British 
Carboniferous  Formations.  I.  Palaeoniscidae  (Palaeont.  Soc),  1877,  No.  2,  1901. —  Vogt,  C,  Quelques 
Observations  qui  servent  ä  la  Classification  des  Ganoides  (Ann.  Sei.  Nat.,  Zool.  ser.  3,  vol.  IV.). 

VOL.  II  F 


66  PISCES  CLAS.s  I 

present.  Fairedßns  well  developed ;  tau  dipht/cercal,  heterocercal,  or  hemi-heterocercal. 
In  the  living  forms — optic  nerves  not  completely  decussating  but  forming  a  chias7na, 
biUbus  aiieriosus  of  the  heart  with  numerous  valves,  intestine  with  a  spiral  valve,  and 
air-bladder  connected  by  a  tube  with  the  gullet. 

When  founding  the  "  Order  "  of  Ganoids,  Agassiz  paid  attention  exclusively 
to  the  dermal  skeleton,  and  included  under  this  denomination  all  fishes  with 
scales  which  consisted  of  a  bony  lower  layer  and  a  superficial  covering  of 
enamel. 

Johannes  Müller  first  attempted  to  define  the  Ganoids  from  anatomical 
characters.  After  the  removal  of  the  Plectognathi,  Lophobranchii,  and  Siluroids 
recognised  as  true  bony  fishes,  and  after  the  assignment  of  Lepidosiren  to  the 
Dipnoi,  there  still  remained  as  true  Ganoids  a  large  number  of  recent  and  fossil 
fishes,  which,  according  to  Johannes  Müller,  formed  a  distinct  sub-class  between 
the  Selachii  and  the  bony  fishes.  While  the  condition  of  the  muscular  bulbus 
arteriosus,  the  incomplete  decussation  of  the  optic  nerves,  and  the  spiral  valve 
in  the  intestine  agree  with  the  former,  the  arrangement  of  the  head  bones,  the 
structure  of  the  fins,  and  usually  also  the  ossification  of  the  skeleton,  are 
suggestive  of  the  bony  fishes.  After  C.  Vogt  had  recognised  in  the 
anatomical  structure  of  Amia  a  true  Ganoid,  with  thiii  elastic  cycloid  scales 
and  a  completely  ossified  skeleton,  the  line  of  demarcation  between  the 
Ganoidei  and  Teleostei  seemed  to  have  been  absolutely  destroyed.  Kner, 
ThioUiere,  Owen,  and  more  recently  Cope  and  Smith  Woodward  have  ventured 
still  further,  suppressing  the  Ganoidei  as  a  separate  group,  and  uniting  its 
members  with  the  Teleostei  under  the  general  denomination  of  Teleostomi. 

The  most  conspicuous,  even  if  not  the  distinctive  featnre  of  the  Ganoids, 
consists  in  their  dermal  covering.  No  other  sub-class  of  fishes  possesses  scales 
which  consist  of  a  thick  bony  inner  layer  and  an  outer  enamel  layer.  In  no 
other  group  is  there  a  union  of  scales  by  peg-and-socket  articulations,  such  as 
is  characteristic  of  the  rhombic-scaled  Ganoids.  There  are,  however,  ganoid 
scales  of  rounded  form,  which  overlap  each  other  exactly  like  cycloid  and 
ctenoid  scales,  and  which  are  sometimes  not  perceptibly  thicker  than  the 
latter ;  but  these  rounded  scales  (Caturus,  3Iegalurus,  Macrarhipis,  Amia)  exhibit 
beneath  the  enamel  covering  an  inner  layer  with  bone  cells,  though  sometimes 
its  thickness  is  excessively  reduced.  The  Spatularias  are  characterised  by 
the  complete  absence  of  scales,  except  on  the  upper  lobe  of  the  tail ;  in  the 
Sturgeons  the  body  is  partly  covered  with  large  bony  plates. 

The  structure  of  the  internal  skeleton  of  the  Ganoids  is  of  special  interest, 
notably  that  of  the  vertebral  column.  In  sonie  Chondrostei  (Acipenser)  the 
vertebral  axis,  with  its  arches  and  spines,  remains  completely  cartilaginous  ;  but 
in  Spatularia,  the  older  Crossopterygii,  almost  all  Heterocerci  and  Pycnodonts, 
and  part  of  the  Lepidostei,  there  is  a  partial  or  complete  ossification  of  the 
arches,  spinous  processes,  and  supports  of  the  median  fins,  this  beginning  at 
the  surface  and  extending  inwards,  so  that  ä  cartilaginous  core  is  usually 
surrounded  by  a  hollow  bony  cylinder.  These  are  termed  "  naked  vertebrae  " 
{Nacktwirbel),  (Fig.  120),  in  contradistinction  to  the  so-called  "  hemi-vertebrae  " 
{Halbwirbel),  and  "ring  vertebrae"  {Hohlwirbel).  In  the  first  (Fig.  121)  there 
develops  below  the  notochord  a  horseshoe-shaped  bony  plate  (hypocentrum, 
intercentrum),  to  which  the  haemal  arches  in  the  caudal  region  are  fixed  ;  the 
upwardly  directed  side-pieces  of  these  hypocentra  are  mostly  attenuated  and 
pointed.     The  vertebral  centrum   proper  is  represented  by  a  pair  of  lateral 


SUB-CLAS8  V 


GANOIDEI 


67 


bo!iy  plates  (pleurocentra),  which  are  usually  pointed  below  and  frequently  fused 
together  dorsally,  thus  f orming  a  second  horseshoe-shaped  half-ring.  According 
to  their  size  the  hypocentra  and  pleurocentra  more  or  less 
completely  Surround  the  soft,  unsegmented  notochord. 
Sometimes  when  the  upper  and  lower  lateral  pieces  de 
not  taper  but  continue  of  uniform  width,  and  meet  together 


i 


i)f 


Fig.  120. 

Two  cautlal  vertebrae 

J'yciioilus    platesstifi, 


Ag.  (after  Heckel; 


Vertebrae  of  Kuthyiiotus  (A),  and  Caturu^  furrdivs,  Ag.  (U).  c,  llib ; 
hyc,  Hypoceiitruiu ;  n,  Neural  arch ;  p,  Parapophysis ;  [jk;  Pleuro- 
centruiii  ;  sp,  Cleft  neural  spine. 


dorsally  and  ventrally,  they  form  two  half-rings,  which  completely  enclose  the 
notochord  (Fig.  121).  In  many  genera  {Earycormus)  the  anterior  abdominal 
region  consists  of  half  vertebrae,  w.hile  the  caudal  region  consists  of  ring 
vertebrae,  which  are  composed  of  two  halves  (Fig.  122).  By  the  complete 
fusion  of  the  two  half  rings,  there  arise  simple,  sheath-like  ring  vertebrae 
(Fig.  122).     In  the  Amiidae   the  vertebral   centra  of  the  abdominal   region 


hyc  . 


h 


Fiti.  122. 
.-1,  Caudal  vertebrae  of  Euri/cormus  speciosus,  Wagn.    B,  Verte- 
brae of  Amia  calva,  Linii.     Front  anterior  part  of  caudal  region. 
/(,    Haenial  arch;   hi/c,   Hypocentrnni  ;    n,  Neural   arch;   plc, 
Pleurocentrnrn. 


Aspidorhynchus,  sp.  Caudal 
vertebrae,  each  beariiig  a 
neural  and  haenial  arch. 


ure  completely  ossified  and  amphicoelous,  while  some  of  those  of  the  caudal 
region  are  still  divided  into  two  halves,  which  correspond  with  the  hypo-  and 
pleuro-centra  of  the  Lepidostei  (Fig.  122,  B). 

The  complete  ossification  of  the  vertebral  column,  as  in  the  bony  fishes,  is 
observed  only  among  the  latest  representatives  of  the  Ganoids,  namely,  the 
Polypteridae  and  the  Lepidosteidae.  Among  the  latter,  moreover,  the  verte- 
l)ral  centra  are  only  concave  behind,  convex  in  front  (opisthocoelous). 

The  hinder  end  of  the  vertebral  column  is  always  produced  into  the  caudal 
tili.  The  true  diphi/cercal  condition  (see  p.  8)  constantly  persists  in  some 
Crossopterygians  (Coelacanthidae)  and  Chondrosteans  (Belonorhynchidae).  In 
most  Crossopterygians  the  caudal  fin  is  hetero-dipht/cercal,  that  is,  the  vertebral 
column  extends  straight,  but  the  rays  of  the  upper  lobe  of  the  fin  are  more 
delicate  and    shorter  than   those  of   the  lower   lobe.       True  Merocercy  and 


68  ♦  PISCES  ,  CLASSi 

hemi-heterocercy  (internal  heterocercy,  external  homocercy,  see  p.  10)  are  very 
common. 

In  many  Ganoids  the  "unpaired  fins,  and  sometimes  also  the  paired  fins,  are 
fringed  on  the  anterior  border  with  the  so-called  fulcra — scale-like  spines  or 
plates  covered  with  enamel,  which  are  serially  arranged  and  partly  overlap 
one  another.  All  the  fin  rays  consist  of  two  (right  and  left)  halves,  and  are 
transversely  jointed,  usually  also  branched  distally. 

Like  the  vertebral  column,  the  skull  also  exhibits  very  variable  degrees  of 
ossification.  In  the  cartilaginous  Ganoids  this  is  almost  exclusively  confined 
to  a  number  of  investing  plates  on  the  cranial  roof  and  the  basicranial  axis. 
The  pterygoid  and  palatine  bones  are  still  fused  together ;  the  mandible  and 
parts  of  the  hyoid  apparatus  are  ossified ;  the  opercular  apparatus  is  feebly 
developed.  In  the  Crossopterygii,  Heterocerci,  and  Lepidostei  the  ossification 
closely  resembles  that  of  the  Teleostei,  while  the-  number  and  arrangement  of 
the  several  bones  agree  essentially  with  the  corresponding  features  in  some  of 
the  least  specialised  members  of  the  latter  sub-class. 

In  the  structure  of  the  pectoral  arch,  and  especially  of  the  anterior  limbs, 
the  various  Orders  of  Ganoids  exhibit  considerable  difFerences,  and  represent 
intermediate  links  between  the  Dipnoi,  Selachii,  and  Teleostei.  In  the 
Crossopterygii,  Chondrostei,  and  Heterocerci  the  clavicle  still  consists  of  three 
separate  membrane  bones ;  while  in  the  Lepidostei  and  Amioidei  the  lower 
Segment  (infraclavicle)  is  completely  fused  with  the  clavicle.  The  small 
structures  behind  and  within  the  clavicle,  corresponding  with  the  scapula, 
coracoid,  and  precoracoid  remain  cartilaginous  in  the  Chondrostei,  probably 
also  in  the  fossil  Crossopterygii ;  in  the  remaining  Ganoids,  on  the  other  band, 
they  are  ossified  exactly  as  in  the  Teleostei.  Moreover,  with  reference  to  the 
Position  and  number  of  the  basal  supports  in  the  pectoral  fins,  most  Ganoids 
agree  with  the  bony  fishes ;  the  earlier  Crossopterygii  alone  possessed  a 
segmented  cartilaginous  axis,  with  biserial  radialia,  as  in  the  Dipnoi. 

Besides  the  anatomical  characters  in  the  dermal  covering  and  the  internal 
skeleton  there  are  still  others  indicating  that  the  Ganoids  are  a  natural  group 
of  fishes.  For  example,  the  somewhat  elongated  muscular  base  of  the  principal 
artery  (bulbus  arteriosus)  is  provided  internally,  as  in  the  Selachii,  with  several 
rows  of  valves,  which  prevent  the  return  of  the  blood  from  the  artery  to  the 
auricle  of  the  heart.  The  gills,  on  the  other  band,  as  in  the  Teleostei,  always 
lie  free  under  an  operculum,  which  usually  consists  of  several  bony  plates. 
Again,  by  the  possession  of  a  spiral  valve  in  the  intestine,  as  well  as  in  the 
structure  of  the  urinogenital  System,  the  Ganoids  approach  the  Selachii  more 
closely  than  the  Teleostei ;  on  the  other  band,  they  all  possess  an  air-bladder 
opening  into  the  guUet,  and  also  produce  numerous  small  eggs,  By  the 
complete  decussation  of  their  optic  nerves,  the  Teleostei  are  distinguished  from 
the  Ganoidei,  in  which  the  branching  optic  nerves  form  a  so-called  chiasma. 

The  Ganoids  exhibit  their  greatest  development  in  Palaeozoic,  Triassic, 
and  Jurassic  formations  ;  and  from  the  base  of  the  Cretaceous  System  upwards 
they  become  more  and  more  replaced  by  the  bony  fishes.  The  few  still 
existing  Ganoids  live  either  exclus-ively,  or  at  least  partly,  in  fresh  water, 
while  the  large  majority  of  the  fossil  forms  occur  in  purely  marine  deposits. 
As  a  rule,  only  the  Tertiary  Ganoids  occur  in  freshwater  formations. 

The  Ganoidei  may  be  divided  into  five  Orders: — (1)  Crossopterygii;  (2) 
Chondrostei ;  (3)  Heterocerci ;  (4)  Lepidostei ;  (5)  Amioidei. 


SUB-CLASS  V 


GANOIDEI 


69 


Order  1.     CROSSOPTERYGII,     Huxley.     Pringe-finned  Ganoids. 

Notochord  persistent  or  vertebrae  ossified.  Tau  diphycercal  or  hetero-diphycercal, 
Infraclavicle  present.  Paired  fins  with  a  scaly  axis  fringed  on  both  sides  by  dermal 
rays.  Branchiostegal  apparatus  between  the  rami  of  the  mandible  consisting  of  a 
pair  of  large  jugular  plafes,  these  in  many  Palaeozoic  genera  flanked  by  a  series  of 
small  lateral  jugular s  and  an  anterior  median  plate.  Ganoid  scales  rhombic  or 
cydoidal,  mmpletely  covering  the  trunk  and  tail. 


Family  1.     Holoptychiidae.      Traquair. 
Body  covered  with  imhricating,  cydoidal  ganoid  scales.     No  ossified  vertebrae. 


Fio.  124. 
Holoptychiios  7iobilisdmus,  Ag.     Upper  0kl  Red  Sandstone  ;  Scotland  (restoration  after  Huxley 


Pectoral  fins  acutely  lobate.     Two  dorsal  fins  and  one  anal  fin,  each  borne  by  a 

distally  expanded  support  (axonosf),  followed  by  one  or  two  rows 
of  short  basal  pieces  (baseosts),  which  support  the  very  numerous, 


Scale  of  Holoptychius 
(Gly}}tolepis).  Outer 
(A),  and  inner  (B) 
aspect.  Old  Red  Sand- 
stoue ;  Wik,  Russia 
(after  Pander). 


Demlrodus  Uporcatus,  Ag.     Tooth  in  side  view  (A),  and  from  below  (B),  nat.  size, 
and  transverse  section  of  the  same  (C),  highly  niagnitted  (after  Pander). 


fine,  dermal  fin  rays.     Lateral  jugular  plates,  clavicle,  aiul  infradavide  present. 


70 


PISCES 


CLASS I 


Read  aiid  branchial  region  covered  with  enamelled  dermal  hones.  Teeth  numerous, 
acutehj  conical,  arranged  on  the  horder  of  the  jaws  :  enlarged  laniary  teeth  in,  a 
second  inner  series  on  several  separate  splenial  hones.  The  teeth  distinguished  hy  a 
very  complicated,  meandering,  folded  structure  (dendrodont).     Devonian. 

The  only  satisfactorily  known  genus  referable  to  this  family  is  Holoptychius, 
Ag.  {Ghjptolepis,  Platygnathus,  Ag.),  (Figs.  124,  125),  from  the  Old  lied' Sand- 
stone of  Scotland,  England,  and  Ireland,  and  from  the  Devonian  of  N.-W. 
Russia,  Bohemia,  Belgium,  the  Eifel,  the  United  States,  Canada,  and  Green- 
land.  Several  species  attain  a  large  size.  Detached  teeth  have  been 
described  as  Dendrodus,  Owen  (Fig.*  126);  Lamnodus,  Ag. ;  and  Apedodus, 
Leidy. 

Family  2.     Rhizodontidae.      Traquair. 

Closely  resemhling  preceding  family,  hut  hoth  paired  fins  with  a  short,  ohtuse  lohe. 
Teeth  few  and  conical,  with  a  loell-defined  pulp  cavity,  the  wall  of  which  is  radial ely 


Fio.  127. 

Rhizodm  hihberti,  Ag, 
Tooth,  I/o  nat.  size 
Lower  Carboniferous 
Edüiburgh. 


folded  in  the  lower  part  of  the  crown. 
Usually  several  tooth -hearing  splenial 
hones  on  the  inner  side  of  the  mandihle. 
Devonian,  Carboniferous,  and  Lower 
Permian. 

lihizodus,  Owen.  (Megalichthys,  Ag. 
p.p.),  (Fig.  127).  Very  large,  incom- 
pletely  known  fishes  with  rough, 
riigose  cycloidal  scales.  Infraclavicle 
with  a  long  upwardly  directed  process. 
Teeth  smooth,  compressed  to  a  sharp 
edge  in  front  and  behind.     B.  hihherti. 


Fig.  1-^b'. 

Rhizodopsis  sauroides,  Williamson  sp.  Outline  re- 
storatious  of  head  and  opercular  apparatus  from  tlie 
Upper  (A),  lower  (B),  and  lateral  (6)  aspects,  about  1/2 
nat.  size.  Upper  Carboniferous ;  Staftbrdshire.  ag, 
Angular  ;  d,  Dentary  ;  /,  Frontal ;  id,  Infradeutary  ; 
j,  Principal  gular  (jugular) ;  Ij,  Lateral  gular  (jugular) ; 
mj,  Median  gular  (jngular);  mv,  Mandible ;  mx, 
Maxiila  ;  ap,  Operculuni ;  or,  Orbit ;  pf,  Postfrontal ; 
priir,  Premaxilla  ;  pop,  Preopercnbun  ;  pa,  Parietal  ; 
so,  Suborbital ;  sop,  Suboperculum  ;  sq,  Squaniosal  ; 
st,  Supratemporal;  r,  ./;',  Cheek-plates  (after  Tra- 
quair). 


Ag.,  and  B.  ornatus,  Traq.,  from  Lower  Carboniferous,  Scotland  and  North- 
umberland.     Allied  species  in  Coal  Measures  of  North  America. 


SUB-CLASS  V 


GANOIDEl 


71 


Strepsodus,  Young  {Deiidroptychius,  Young ;  Archichthys,  Hanc.  and  Atth.). 
Large  and  medium- sized  fishes  with  slender  and  somewhat  curved  teeth, 
which  are  not  compressed  to  sharp  edges.  S.'  sauroides,  Binney  sp.,  from  Goal 
Measures  of  England,  Scotland,  and  Ireland.  Other  species  from  Lower 
Carboniferous  of  Scotland,  Ireland,  and  Nova  Scotia. 

Ehizodopsis,  Young  {Dittodus,  Ganolodus,  Characodus,  Gastrodus,  Owen), 
(Fig.  128).  Scales  oval,  with  an  extremely  thin  layer  of  punctate  ganoine. 
Teeth  round  in  section,  smooth.  Vertebral  axis  with  ring  vertebrae.  The 
small  type  species  represented  by  fine  examples  in  the  English  Goal  Measures. 
Fragments  in  the  Goal  Measures  of  Silesia,  Nova  Scotia,  and  Illinois. 

Gyroptychius,  M'Göy  ;  Tristichopterus,  Egerton  ;  Eusthenopteron,  Whiteaves  ; 
Polyplocodus,  Pander  ;  Sauripterus,  Hall.  Devonian  and  Old  Red  Sandstone ; 
Europe  and  North  America. 


Family  3.     Osteolepidae.     Smith  Woodward. 

Body  slender,  covered  with  rhomhic  ganoid  scales.  Bing  vertebrae  at  least  in  the 
caudal  region.  Baired  fins  with  a  short,  obtuse  lobe.  Teeth  conical,  only  externally 
folded  at  the  base,  as  in  Bhizodontidae.     Devonian  and  Garboniferous. 

Osteolepis,  Ag.  {Tripterus,  Triplopterus,  M'Goy),  (Fig.  129).  Granial  roof 
bones  in  advance  of  the  parietals  fused  into  a  continuous  shield,  pierced  by  a 


Fig.  12y. 
Osteolepis  viacrolepidotns,  Ag.     Lower  Old  Red  Saiidstone  ;  Scotland  (restoration  after  Pander). 


present. 

Scales 

Pander. 

Lower 


median  frontal  (pineal)  foramen.  An  anterior  median  jngular  plate 
Teeth  round  in  section.  First  dorsal  fin  in  front  of  the  pelvic  pair. 
smooth  and  punctate.  0.  macrolepidolus,  Ag.,  and  0.  microlepidotus, 
Lower  Old  Red  Sandstone ;  Scotland. 

Thursius,  Traq.      As  Osteolepis,  but  first  dorsal  opposite  pelvic  fins. 
Old  Red  Sandstone  ;  Scotland. 

Diplopterus,  Ag.     Lower  Old  Red  Sandstone  ;  Scotland.         , 

MegalicMhys,  Ag.  {Centrodus,  M'Goy  ;  Bhomboptychius,  Young  ;  Edosteorhachis, 
Gope).  Granial  roof  bones  in  advance  of  the  parietals  rarely  fused  into  a 
continuous  shield,  without  a  median  frontal  foramen. 
Teeth  round  in  section.  First  dorsal  fin  nearly  opposite 
the  pelvic  pair.  Scales  smooth  and  punctate.  Garboni- 
ferous of  Great  Britain  and  North  America.  Lower 
Permian  of  Texas.  M.  hibberti,  Ag.,  the  best  known 
British  species  from  the  Goal  Measures. 

Glyptopomus,  Ag.  (Glyptolaemus,  Huxley),  (Fig.  130). 
Bones  of  cranial  roof  not  fused  together ;  a  median 
frontal  (pineal)  foramen.  External  bones  and  scales 
ornamented  with  irregulär  reticulating  rugae  or  fused 
series  of  tubercles.  Upper  Old  Red  Sandstone ;  Scotland,  possibly  also 
Belgium  and  Pennsylvania. 


Fio.  130. 
Glyptopomus  kinnairdi, 
Huxley.  Scale,  enlarged. 
Upper  Old  Red  Sandstone ; 
Dura  Den,  Fifesliire  (after 
Huxley). 


72 


PISCES 


CLASS  I 


Family  4.     Coelacanthidae.     Huxley.i 

Body  covered  with  thin,  cydoidal  ganoid  scales.  No  ossißed  vertebrae.  Arches, 
spinous  jprocesses,  and  supports  of  caudal  fin  superficially  ossified.  Air  hladder 
ossified.  Paired  fins  with  a  short,  obtuse  lobe.  Fach  of  the  two  dorsal  fins  and  the 
anal  fin  supported  by  a  simple,  usually  proximally  forked  plate,  which  in  the  anterior 
dorsal  is  in  dired  contact  with  the  dermal  rays.  Caudal  fin  distindly  diphycercal, 
hörne  above  and  below  by  numerous  simple  supports,  and  terminating  in  a  small  pro- 
jeding  tufted  fin.  Only  one  opercular  bone  on  eadi  side  and  a  pair  of  jugular 
plates  ;  but  several  splenial  bones  present.     Upper  Devonian  to  Upper  Cretaceous. 

Coelacanthus,  Ag.  (Hoplopygus,  Ag. ;  Conchiopsis,  Cope ;  Bhahdoderma,  Eeis). 
Teeth  absent  on  the  margin  of  the  jaws,  but  a  few  hollow,  conical  teeth 
within.  Supplementary  caudal  fin  prominent.  External  bones  and  scales 
ornamented  with  series  of  tubercles  or  fine  ridges  of  ganoine ;  fin  rays  not 
denticulated.  Carboniferous  and  Permian  of  England,  Scotland,  Germany 
(Kupferschiefer),  and  North  America.  Fragments  probably  also  in  Upper 
Devonian  of  Harz  Mountains. 

Graphiurus,  Kner ;  Heptanema,  Bellotti.     Trias  of  Raibl  and  Perledo. 

Diplurus,  Newb.     Trias  ;  New  Jersey  and  Connecticut. 

ündina,  Münster  (Holophagus,  Egerton),  (Fig.  131).  Supplementary 
caudal  fin  prominent.     All  the  fin  rays  robust,  broad,  and  closely  articulated 


Fig.  131. 

ündina  penicülata,  Münst.  Upper  Jurassic  (Lithographie 
Stone) ;  Landt,  iiear  Eichstädt.  1/3  (after  Hnxley).  .;,  Jugular  plates  ; 
b,  Scales  froni  upper  region  of  trunk  of  Umlina  ac'utidens,  Reis. 


distally  ;  the  anterior  rays  of  the  first  dorsal  and  caudal  fins  denticulated  or 
tuberculated.  External  bones  and  scales  rugose  and  tuberculated.  Lower 
Lias  to  Lower  Kimmeridgian. 

Libys,  Münst.;  Coccoderma,  Quenst.  Lithographie  Stone  (Lower  Kim- 
meridgian) ;  Bavaria  and  Würtemberg.  C.  substriolatum,  Huxl.  sp.,  from 
Kimmeridge  Clay,  England. 

^  Huxley,  T.  IL,  Illustrations  of  the  Structure  of  tlie  Cros.soptervgian  Ganoids  (Mem.  Geol. 
Surv.  dec.  XII.),  1866.— is-m,  0.,  Die  Coelacanthinen  (Palaeontogr. "  vol.  XXXV.),  1888;  also 
Geogu.  Jahresh.,  München,  1892. 


suB-CLASs  V  PGANOIDEI  73 

Macropoma,  Ag.  Maxilla,  vomer,  and  palatine  with  conical  teeth.  Sup- 
plementary  caudal  fin  unkriown.  Fiii  rays  robust  and  straight,  not  expanded 
distally,  with  distant  articulations  ;  a  double  series  of  small,  upwardly  pointing 
denticles  on  nearly  all  the  rays  of  the  first  dorsal  and  caudal  fins.  Turonian 
and  Senonian  of  Europe.  M.  mantelli,  Ag.,  especially  well  preserved  in  the 
English  Chalk. 

Family  5.     Polypteridae.     Huxley. 

Body  covered  with  thick,  rhombic  ganoid  scales.  Vertebrae  and  the  complete 
internal  skeleton  ossißed.  Tail  diphycercal,  Pectoral  fins  with  short,  obtuse  lobe, 
the  numerous,  short,  fan-like  basalia  attached  to  two  diverging  bones  (propterygium 
and  metapterygium)  and  a  median  mesopterygium.  Dorsal  fin  single,  remarkably 
extended,  the  spine-like  rays  borne  by  a  corresponding  number  of  Supports.  Only  a 
Single  pair  of  jugular 
plates.  Teeth  sharply 
conical,  toith  simple  pulp 
Recent. 


^e: 


Fig.  132, 


To   this    family   be- 

long     the     two     genera,  Polyptems  öichir,  GeoüY.     Recent;  Upper  Nile. 

Polypterus  (Fig.  132)  and  Calamoichthys,  living  in  the  rivers  of  tropical  Africa. 


Order  2.     CHONDROSTBI.     Cartilaginous  Ganoids. 

Notochord  persistent,  and  endoskeleton  chiefly  cartilaginous;  head  covered  with 
bony  dermal  plates,  Teeth  small  or  wanting.  Opercular  apparatus  imperfectly 
developed,  the  branchiostegal  rays  usually  absent.  Infraclavicle  present.  Paired 
fins  without  a  scaly  axis,  but  each  pelvicfin  with  a  row  of  cartilaginous  basal  Supports. 
A  Single  dorsal  and,  anal  fin,  with  dermal  rays  more  numerous  than  their  Supports. 
Caudal  fin  heterocercal  (rarely  diphycercal),  and  the  upper  lobe  usually  covered  with 
rhombic  scales.     Trunk  almost  or  completely  naked,  or  with  rows  of  bony  plates. 

Family  1.     Ohondrosteidae.     Smith  Woodward.^ 

Parietal  and  frontal  bones  paired  ;  a  large  squamosal  bordering  the  parietals  on 
each  side.  Jaws  toothless,  and  premaxilla  absent.  Operculum  small,  suboperculum 
large ;  a  few  branchiostegal  rays  present.  Trunk  naked,  only  the  upper  fulcrated 
lobe  of  the  tau  with  elongated,  oat-shaped  ganoid  scales.     Lias. 

Chondrosteus,  Egerton.  Mouth  very  small  and  inferior;  jaws  toothless; 
maxilla  arched,  much  expanded  behind  and  tapering  in  front.  About  ten 
branchiostegal  rays,  but  no  gular  plate.  Dorsal  fin  short-based,  opposed  to 
the  pelvic  pair.  Trunk  naked.  C.  acipenseroides,  Eg.,  about  a  metre  in 
length,  known  by  nearly  complete  skeletons  from  the  Lower  Lias  of  England. 

Gyrosteus,  Sm.  Woodward  {ex  Ag.  MS.).  Usually  much  larger  than 
Chondrosteus,  and  the  toothless  maxilla  expanded  in  its  front  portion  for  a 
palatine  articulation.  G.  mirabilis,  Sm.  Woodw.  {ex  Agassiz,  MS.),  represented 
by  fragments  in  the  Upper  Lias  of  Whitby. 

1    Woodward,  A.  S.,  On  the  Palaeontology  of  Sturgeous  (Proc.  Geol.  Assoc.   vol.  XL),  1889  ; 
also  Proc.  Yorks.  Geol.  and  Polyt.  Soc.  vol:  XIII.  1898,  p.  461. 


74 


PISCES 


Family  2.     Acipenseridae.     Sturgeons. 

Elongated  fishes  with  a  produced  snout,  and  small  toothless  mouth  without  pre- 
maxilla.  Parietal  and  frontal  hones  large,  unaymmetrical,  and  granulated.  Oper- 
mlum  imompletely  developed,  not  quite  covering  the  branckial  opening  ;  hranchiostegal 
rays  ahsent.  Dorsal  and  anal  fins  hörne  hy  two  rows  of  Supports  (axonosts  and 
haseosts) ;  caudal  fin  strongly  heterocercal,  the  large  upper  lobe  ridged  with  fulcral 
scales.  Trunk  with  five  longitudinal  series  of  keeled  bony  plates.  Tertiary  and 
Recent. 

The  sturgeons  of  the  two  living  genera,  Acipenser  and  Scaphirhynchus, 
irihabit  the  seas  of  the  northern  hemisphere,  and  enter  the  rivers  of  Europe, 
A.sia,  and  North  America.  Fossil  remains  are  rare.  An  Eocene  species 
{Acipenser  toliapicus,  Ag.)  is  represented  by  scutes  in  the  London  Clay  of 
Sheppey.  Scutes  and  pectoral  fin  rays  are  also  known  from  Upper  Eocene 
and  later  deposits  in  Europe,  and  from  the  Miocene  of  Virginia,  U.S.A. 

Family  3.     Polyodontidae.     Paddle-fishes. 

Snout  very  long  and  spatidate.  Parietal  and  frontal  bones  paired.  Mouth 
large,  with  minute  teeth  in  hoth  jaws ;  no  premaxilla.  Branchiostegal  rays  absent. 
Scales  rudimentary  or  absent,  except  on  the  sides  of  the  upper  caudal  lobe,  which  is 
ridged  with  large  fulcral  scales.     Cretaceous  (?)  or  Eocene  to  Recent. 

Crossopholis,  Cope.  Rostrum  covered  with  small  stellate  bones.  Scales  of 
trunk  small,  thin,  and  separated  ;  each  being  a  grooved  disc  with  posterior 
denticulations  like  a  fringe.  C.  magnicaudatus,  Cope ;  Eocene  (Green  River 
Shales),  Wyoming. 

Pholidwrus,  Sm.  Woodw.  Known  by  caudal  ridge  scales  only,  from  the 
Upper  Chalk,  Kent. 

Polyodon  {Spatidaria)  living  in  the  Mississippi,  Psephurus  in  Chinese  rivers. 


Family  4.     Belonorhynchidae.     Smith  Wood  ward.  ^ 

Slender  fishes  with  a  much  elongated,  pointed  snout.  Mouth  very  large,  and 
jaws  with  numerous  conical  teeth  of  different  sizes.  Opercular  apparatus  reduced, 
without  branchiostegal  rays.  Fin  fulcra  minute  or  absent ;  dorsal  arid  anal  fins 
small  and  remote ;  caudal  fin  diphycercal.  Trunk  with  four  longitudinal  rows  of 
small,  keeled,  scale-like  plates.     Trias  and  Lias. 

Belonorhynchus,    Bronn.    {Ichthyorhynchus,    Bellotti ;    Saurorhynchus,    Reis.), 


Fig.  133. 
Jkloiiorhyndins  striulat US,  Bronn.     Keuper ;  Kaibl,  Carinthia.     Xat.  size. 

(Fig.    133).      Head  and  trunk  excessively  elongated.      Jaws  approximately 
equal  in  length,  and  mandible  remarkably  deep  behind.     Head  bones  exter- 

^    Woodioard,  A.  S.,  The   Fossil  Fishes  of  the   Hawkesbury  Series   (Meni.  Geol.  Snrv.   N.  S. 
Wales,  Palaeont.  No.  4),  ISQO.—Jieis,  0.,  Geogii.  Jahresh.,  IV.  München,  1891. 


ik 


suB-CLASs  V  GANOIDEl  75 

nally  ornamented  with  Striae,  rugae,  or  reticulations.     The  remote  dorsal  and 

anal  fins  opposed  to  each  other ;  the  diphycercal  caudal  fin  truncated  at  its 

hinder  margin.      Of   the   four   series   of   imbricating   keeled 

dermal  scutes  one  extends  along  the  back,  another  along  the 

ventral  border,  and  the  other  two  smaller  series  along  the 

tianks.      The  ventral  scutes   form  a  ring  round   the  region 

of  the  anus.     Belonorhynchus  occurs  in  the  Trias  of  the  Alps  ^.^^  ^3^ 

(Raibl,  Perledo,  Seefeld)  and  Australia  (Hawkesbury  Forma-      sauricUhy»    acumi- 

tion),  and  is  represented  by  skulls  and  other  fragments  in  ^««««..  Ag.    Tooth, 

the  Lias  of  Jingland  and  Germany  {ßelonostomus  acutus,  Ag.),    Kemnath.wurtein- 

The  teeth,  jaws,  and  skulls  from  the  Muschelkalk,  Keuper,    *'^'^' 

and  Rhaetic,  described  under  the  name  of  Saurichthys,  Ag.  (Fig.  134),  probably 

belong  to  Belonorhynchus. 


Order  3.     HBTBROCBRCI.     Zittel.i 

Notochord  persistent,  hut  arches,  spinous  processes,  and  fin  supports  more  or  less 
ossified  ;  head  covered  with  hony  dermal  plates.  Opercular  apparatus  well  developed, 
and  branchiostegal  rays  numerous.  Infraclavicle  present.  Unpaired,  and  usually 
also  paired  fins  fringed  with  fulcra.  Paired  fins  without  scaly  axis,  hut  each  pelvic 
fin  with  a  row  of  imperfectly  ossified  basal  supports.  A  single  dorsal  and  anal  fin, 
with  articulated  rays  which  are  more  numerous  than  their  supports.  Caudal  fin 
heterocercal.     Scales  rhomhic  or  rhomboidal,  rarely  cycloidal. 

In  their  skeletal  structure  and  the  characters  of  their  paired  fins,  the 
Heterocerci  agree  so  closely  with  the  Chondrostei,  that  they  are  united  with 
the  latter  by  Traquair  under  the  ordinal  name  of  Acipenseroidei.  In  their 
out  ward  aspect  they  bear  a  superficial  resemblance  to  the  Lepidostei.  The 
Chondrostei,  Heterocerci,  and  Lepidostei,  probably  form  three  difFerent 
specialised  branches  from  one  and  the  same  primitive  group. 

Family  1.     Palaeoniscidae.     Vogt  emeiid.  Traquair. 

Trunk  elongate-fusiform.  Head  bones  more  or  less  enamelled.  Teeth  slender, 
conical  or  styliform.  Scales  ganoid,  rhombic  in  shape,  rarely  cycloid  on  the  trunk. 
Devonian  to  Upper  Jurassic. 

Cheirolepis,  Ag.  Jaws  with  an  outer  row  of  minute  teeth  and  an  inner  row 
of  stouter  teeth.  Dorsal  fin  remote,  arising  behind  the  origin  of  the  anal  fin. 
Scales  very  small,  rhombic,  or  almost  Square.  C.  cummingiae,  Ag. ;  Lower  Old 
Red  Sandstone,  Scotland.  C.  canadensis,  Whiteaves.  Upper  Devonian  ;  Scau- 
menac  Bay,  Canada. 

Canobius,  Gonatodus,  Traquair.  Lower  Carboniferous  ;  Scotland.  G.  moly- 
neuxi,  Traq.  ;  English  Goal  Measures. 

Amblypterus,  Ag.  Mouth  and  teeth  small.  Fins  with  delicate  fulcra. 
Scales  smooth.  Several  species  from  Lower  Permian  (Rothliegendes)  of 
Rhenish  Prussia,  Bohemia,  and  France.     A.  latus,  Ag.  ;  A.  duvernoyi,  Ag.  sp. 

Eurylepis,  Newb.  (Fig.  135).     Small  fishes  with  small  fins,  the  fin  rays  not 

^  Traquair,  R.  If.,  The  Ganoid  Fishes  of  the  British  Carboniferous  Formations  (Pakieont.  Soc.) 
No.  1,  1877,  No.  -2,  1901. — On  Amhlypterus,  Palaemiscus,  Gyrolepis,  and  Pygopterns  (Quart.  Journ. 
Geol.  Soc.  vol.  XXXIII.),  1877.— Ön  Eskdale  Fishes  (Trans.  Roy.  Soc.  Edinb.  vol.  XXX.).  1881. 


76 


PISCES 


CLASS I 


divided  distally,  and  the  caudal  obliquely  truncated.     Teeth  small.     Scales 

rugose,  denticulated  on  the  hirider 
border ;  two  or  more  rows  of 
scales  on  the  flank  remarkably 
deepened.  Goal  Measures  ;  Ohio, 
and  rarely  England. 

Nematoptychius,  Ehadinich  thys, 
Traquair ;  Cycloptychius,  Young. 
Carboniferous. 

Fygopterus,  Ag.  Kupfer- 
schiefer. 

Palaeonisciis,  Blv.  emend.  Tra- 
quair (Fig.  136).  Slender  fishes, 
small  or  of  moderate  size.  Teeth 
sharply  pointed,  of  diff'erent  sizes. 
Eins  small,  the  rays  articulated 
and  divided  distally.  Dorsal  in 
front  of  the  anal  fin.     Scales  rhombic,  marked  with  irregulär  oblique  furrows. 


Fig.  135. 

Eurylepis  tuberculatus,  Newb.     Goal  Measures  : 
Linton,  Ohio. 


6  Fig.' 136. 
Palaeonisciis  macropomus,  Ag.  Restora- 
tion  of  head  {A),  pectoral  arch  (ß),  and 
caudal  fin  (C).  Natural  size.  Kupfer- 
schiefer ;  Thuringia.  af,  Anterior  frontal ; 
aq,  Angular ;  hr,  Branchiostegal  rays  ;  d, 
ciavlcle  ;  d,  Dentary  ;  e,  Ethnioid  ;  /, 
Frontal ;  id,  Infraclavicle  ;  top,  Suboper- 
culum  ;  mx,  Maxilla  ;  n,  Narial  opening  ; 
op,  Operculum ;  p,  Parietal ;  pd,  Post- 
clavicle ;  pop,  Preoperculuni ;  pt,  Post- 
temporal ;  pinx,  Premaxilla  ;  q,  Squa- 
mosal ;  sd,  Supraclavicle ;  so,  Circuni- 
orbital  ring  and  suborbital«  ;  st,  Supra- 
temporal. Dotted  lines  indicate  course  of 
sensory  canals  (after  Traquair). 


P.  freieslebeni,  Blv.  (Eig.  136),  and  other  species  very  common  in  the  Kupfer- 


8UB-CLASS  V 


GANOIDEI 


77 


I 


schiefer   of    Thuringia   and    Eiechelsdorf,   Hesse ;    also   found   in   the   Upper 
Permian  of  England,  France,  and  Russia. 

Elonichthys,  Giebel  (Bhabdolepis,  Troschel ;  Cosmoptychius,  Traquair),  (Figs. 
137,  138).  Teeth  of  difl'erent  sizes.  Fins  large,  with  fulcra,  and  the  rays 
distally  divided.  Dorsal  in  front  of  the  anal  fin.  Scales  rhombic,  obliquely 
sculptured.     E.  germari,  Gieb.,  from  Goal  Measures  of  Saxony.     Other  species 


Fig.  137. 

Elonichthys  (Cosmoptychiun) 
striatus,  Ag.  sp.  Scale  Iroiu 
outer  {A\  and  inner  (B) aspects, 
three  tinies  nat.  size.  J^ower 
Carbo7iiferoiis  ;  f Edinburgh 
(aller  Traquair). 


Fig.  138. 

Elonichthys  (lihabdolepis)  macropterus,  Bronn  sp.'  Lower  Permian  (Roth- 
liegenden) ,   Lebacli,  near  Saarbrücken,  Rhenish  Prussia  (restoratiou  after 

Agassizi.  s 


Gyrolepis  ornatus,  Gieb. 
1.  Muschel- 
kalk ;  Esperstädt  (after 
Dam  es). 


from  the  Carboniferous  of  England,  Scotland,  and  North  America ;  also  from 
the  Lower  Permian  of  Rhenish  Prussia  and  Bohemia. 

Acrolepis,  Ag.  Closely  resembling  Elonichthys,  but  scales  more  deeply  over- 
lapping.  A.  sedgwicki,  Ag.,  from  Upper  Permian  (Marl  Slate  of  Durham  and 
Kupferschiefer  of  Germany).  Other  species  in  Carboni- 
ferous of  England,  Scotland,  and  Belgium. 

Gyrolepis,  Ag.  (Fig.  139).  Anterior  rays  of  pectoral 
fins  not  articulated.  Operculum  deep  and  narrow.  Scales 
marked  with  irregulär  oblique  and  curved  rugae.     Common  ^^^-  ^^^ 

in  the   Muschelkalk   and    Ehaetic   Bone-bed,    but   usually   sdSSarg, 
only  isolated  scales. 

Myriolepis,  Egerton.      Scales   very   small.     M.  clarkei, 
Eg.,  from  Trias  (Hawkesbury  Formation),  New  South  Wales.     An  allied  fish 
in  the  Goal  Measures  of  Kilkenny,  Ireland. 

Oxygnathus,  Egerton  (Thrissonotus,  Cosmolepis,  Egerton).  Fins  large,  with 
small  fulcra.  Pectoral  fin  rays  only  articulated  distally.  Dorsal  in  front  of 
anal  fin.  Scales  small,  but  thick,  obliquely  sculptured.  0.  ornatus,  Eg.,  from 
Lower  Lias,  Lyme  Regis. 

Centrolepis,  Egerton.     Lower  Lias  ;  Lyme  Regis. 

Atherstonia,  Sm.  Woodw.  Trias  (Karoo  Formation) ;  Colesberg,  South 
Africa. 

Coccolepis,  Ag.  Scales  thin,  rounded,  and  very  deeply  overlapping;  orna- 
mented  with  tubercles.  Fulcra  minute  or  absent.  Dorsal  in  front  of  anal  fin. 
Small  species  in  the  Upper  Jurassic  Lithographie  Stone  of  Bavaria  {C.  hiLck- 
landi,  Ag.),  the  Purbeck  Beds  and  Lower  Lias  of  England.  A  larger  species 
{C.  australis,  Sm.  Woodw.)  in  the  Hawkesbury-Wianamatta  Formation  of  New 
South  Wales.     Only  known  Palaeoniscid  ranging  above  the  Lias. 

Cryphiolepis,  Traquair.      Fins   large,  with   fulcra.      Scales  large  and  thin, 


78 


PISCES 


CLASS I 


iiiore  or  less  rounded,  very  deeply  overlapping,  and  externally  striated. 
Carboniferous ;  Scotlarid. 


Lower 


Family  2.     Platysomidae.     Traquair. 

Trank  deeply  fusiform  or  irregularly  rhombic  and  laterally  compressed.  Head 
hones  enamelled ;  hyomandibular  nearly  vertical  and  mouth  small ;  teeth,  when 
preserif,  more  or  less  hlunt,  chiefly  on  tlie  pterygoid  and  splenial  hones.  Fins  with 
fulcra  :  pelvic  fins  small  or  absent ;  dorsal  fin  single,  much  extended.  Scales  rhombic^ 
deepened  on  the  flank,  each  with  an  inner  vertical  keel  projecting  as  a  peg  at  the  vpper 
border.     Carboniferous  and  Permian. 

Eurynotus,  Ag.  (Pledrolepis,  Ag.).     Trunk  deeply  fusiform.     Teeth  short, 

obtusely  conical  to  spher- 
oidal.  Pectoral  fins 
large  ;  dorsal .  fin  arising 
opposite  the  pelvic  pair 
and  extending  to  the 
caudal  fin  ;  anal  fin  short- 
based.  F.  crenatus,  Ag., 
from  Lower  Carbonifer- 
ous, Scotland;  other 
species  from  Ireland  and 
Belgium. 

Mesolepis,  Young; 
Wardiclähys,  Traquair. 
Carboniferous ;  Scotland 
and  England. 

Cheirodus,  M'Coy 
(Amphicentrum,  Young), 
(Fig.  140).  Trunk  deep, 
rhombic.  Pectoral  fins 
very  small,  pelvic  fins  absent.     Dorsal  and  anal  fins  directly  opposed,  and  both 


Cheirodus  granuiosus,  Young  sp. 
Restored.     Lettering 


Fi«.  140. 

Goal  Measures  ;  North  Staffordsliire. 
in  Fig.  13(5  (after  Traquair). 


l'latyaormis  striatus.  Ag. 
Durhain.     1/4  nat 


Fio.  141. 
Upper  Permian  (Maguesian  Liniestone)  : 
size  (restoration  alter  Traquair). 


Fio.  142. 

Platysoiuas  parvulus,  Ag. 
Scale,  outer  (J),  and  inner 
(/.')  a8])eets,  twice  nat.  size. 
Goal  Measures  ;  England. 


much  extended.     Teeth  absent,  but  pterygoid  and  splenial  with  denticulated 


süB-CLAssv  GANOIDEI  -  79 

border.  Ö.  gnuiulosus,  Yoimg  sp.  (Fig.  140),  from  Eiiglish  and  Scottish 
Goal  Measures.     Other  species  in  Lower  Carboniferous,  England  and  Scotland. 

Cheirodopsis,  Traquair.     Lower  Carboniferous  ;  Scotland. 

Flati/somus,  Ag.  (Figs.  141,  142).  Trunk  deep,  rhombic  or  discoidal. 
Teeth  small,  styliform.  Pectoral  and  pelvic  fins  small.  Scales  finely  striated. 
F.  sfriatus,  Ag.  (Fig.  141),  from  Upper  Permian  (Marl  Slate  of  England, 
Kupferschiefer  of  Germany).  Upper  and  Lower  Garboniferous  of  England 
and  Scotland ;  Goal  Measures  of  North  America ;  Permian  of  Orenburg, 
Russia. 

1  Dort/pteras,  Germar.  A  scaleless  fish,  showing  internal  skeleton.  Rare 
in  Upper  Permian  (Marl  Slate  of  Durham  and  Kupferschiefer  of  Germany). 

1  Family  3.     Catopteridae.      Woodward. 

Trunk  elougate  or  elongate-fasiform ;  tau  ahhreviate  heterocercal.  Head  bones 
well  developed,  ganoid  ;  m  median  series  of  cranial  roof  bones  ;  teeth  slender,  conical. 
Dorsal  fin  Single  and  not  much  extended.     Scales  rJwtnbic,  ganoid.     Trias. 

Bictyopyge,  Egerton.     Teeth  small.     Dorsal   opposite  or  slightly   in  front 

jf  the  anal  fin.      Upper   lobe  of  tail   very  short ;  caudal  fin  forked.     Scales 

'thombic,  smooth   or  with   few  oblique  furrows.      All  species  small.      Upper 

Trias  of  England,  Germany,  Virginia,  U.S.A.,   South  Africa,  and  Australia. 

Also  J).  rhenana,  Deecke,  from  Lower  Trias  (Bunter),  near  Basle,  Switzerland. 

Catopterus,  Redfield  (Bedfieldius,  Hay).  As  Dictf/opt/ge,  but  origin  of  dorsal 
behind  that  of  anal  fin.     Fulcra  fine.      Trias ;  North  America. 

Order  4.     LBPIDOSTBI.     Huxley.i 

Notochord  persistent,  or  vertebrae  in  various  degrees  of  ossification.  Opercidar 
apparatus  usually  complete,  with  branchiosfegal  rat/s,  and  offen  a  gular  plate ;  at 
least  one  series  of  postorbitals  on  the  cheek  betweeii  the  orbit  and  preoperculum.  Teeth 
pointed  or  conical.  No  infraclavicle.  Unpaired,  and  usually  also  paired  fins  fringed 
with  fulcra  ;  Supports  of  dorsal  and  anal  fins  equal  in  number  to  the  dermal  rays. 
Caudal  fin  hemi-heterocercal.  Scales  rhombic  or  rhomboidal,  arranged  in  oblique 
series,  and  frequently  united  above  and  below  by  peg-and- socket  articulations. 

To  the  Lepidostei  are  referred  the  "  bony  pikes "  at  present  distributed 
throughout  the  freshwaters  of  North  America,  besides  a  large  number  of  fossil 
genera  from  Mesozoic  formations.  They  are  remarkably  closely  related  to  the 
Palaeoniscidae,  and  in  the  ossification  of  their  internal  skeleton  they  represent 
a  higher  grade  of  the  same  type.  Except  a  single  genus  from  Permian  deposits 
(Acentrophorus),  the  Lepidosteoids  are  confined  to  the  Trias,  Jurassic,  Creta- 
ceous,  and  Tertiary,  both  in  Europe  and  North  America.  Their  maximum 
development  occurs  in  the  Jurassic  period.  While  the  Lepidosteoids  are 
closely  related  on  the  one  band  to  the  Palaeoniscids,  they  approach  so  closely 
to  the  Amioids  on  the  other,  that  it  is  impossible  to  separate  them  distinctly 
from  the  latter. 

'  E'jerton,  P.  M.  </.,  Figures  aiul  Desciiptioiis  of  British  Orgauic  Reniains  (Meni.  Geol.  Surv. 
'lec.  \'I.,  VIII.,  IX.,  XIII.). — Knei\  R.,  Die  Fische  der  bitmiiiiiösen  Schiefer  von  Rail>I  in  Kärnthen 
(Sitzungsb.  k.  Akad.  Wiss.  Wien,  math.-naturw.  Cl.  vol.  LIII.),  1866  ;  and  Nachtrag,  ihüf.  vol.  LV. 
1867.  —  Die  fossilen  Fische  der  Asphaltschiefer  von  Seefeld  in  Tyrol  (ibicf.  vol.  LIV.),  1866;  and 
Nachtrag,  ibid.  vol.  LVI.  1867.  —  Vetter,  ß.,  Die  Fische  ans  <leni  lithographischen  Schiefer  in 
Dresdener  Museum  {Mittheil.  k.  niineral.-geol.  Mus.  Dresden),  1881. 


80 


PISCES 


Family  1.     Sty  lodontidae.     Wagner.^ 

Jaws  and  vomer  with  several  rows  of  teeth,  those  of  tlie  outer  row  styliform. 
Vertehral  column  consisting  of  hemi-vertebrae  or  ring-vertebrae.  AU  fins  fringed  with 
fulcra.  Caudal  fin  both  internally  and  externally  hemi-heterocercal,  the  Upper  lohe 
more  extensively  scaled  tlian  the  lower  lobe,     Upper  Permian  to  Upper  Jurassic. 

Acentrophorus,  Traq.  Trunk  fusiform.  Dorsal  fin  short,  opposite  tlie 
Space  between  the  pelvic  and  anal  fins.  No  enlarged  ridge  scales.  A.  varians, 
Kirkby  sp.,  and  other  species  from  Magnesian  Limestone,  Durham.  A. 
chicopensis,  Newb.     Trias  ;  Connecticut  Valley,  U.S.A. 

Semionotus,  Ag.  (Ischypterus,  Egert.).  Trunk  fusiform.  Dorsal  fin  large 
and  extended,  its  liinder  part  opposed  to  the  anal  fin.     Dorsal  series  of  pointed 

ridge  scales  forming  a  pro- 
minent crest.  Fin  fulcra 
sometimes  very  large.  Scales 
and  head-bones  smooth  or 
but  feebly  ornamented.  S. 
bergeri,  Ag.,  from  Keuper  of 
Coburg  and  Thuringia.  *S'. 
kapß,  Fraas  (Fig.  143),  from 
Keuper,  Haslach,  near 
Stuttgart.  Other  species  from 
the  Bunter,  Muschelkalk, 
Keuper,  and  Ehaetic  of  Europe,  also  from  the  Upper  Karoo  Formation  of 
South  Africa,  the  Hawkesbury  Formation  of  New  Sout*h  Wales,  and  Trias  of 
Connecticut  Valley  and  New  Jersey,  U.S.A. 


Fig.  143. 

Semionotus  Jcapffi,  Fraas.     Keuper  (Stubensandstein) ;  Stuttgart. 
2/3  uat.  size  (after  O.  Fraas). 


Fig.  144. 


Dapedüis  pholidotus,  Ag.     Upper  Lias  ;  Boll,  Würteinberg.     1/2  nat.  size. 
B,  C,  Teeth,  nat.  size  (after  Quenstedt). 

Crenilepis,  Dammes.    Muschelkalk.     IIomoeolepis.WsLgner.    Upper  Lias;  Boll. 
Dapedius,  de  la  Beche   (Amblyurus,  Ag. ;  Aechmodus,  Egerton),  (Figs.  144, 

-  Sträver,  J.,  Fossile  Fische  aus  dem  Keupersandstein  von  Coburg  (Zeitschr.  deutsch,  geol.  Ges. 
vol.  XVI.),  18Qi.— Wagner,  A.,  Die  Griffelzähner  (Stylodontes),  (Gelehrt.  Anzeig.  k.  bay.  Akad. 
vol.  L.),  1860. — Deecke,  W.,  Ueber  Fische  aus  verschiedenen  Horizonten  der  Trias  (Palaeoutogr.  vol. 
XXXV.),  l88S.—Netoberry,  J.  S.,  Fossil  Fishes  and  Fossil  Plauts  of  the  Triassic  Rocks  (Mouogr. 
U.S.  Geol.  Surv.  vol.  XIV.),  1888.— Schelhvien,  E.,  Ueber  Semionotus  Agassiz  (Schriften  Phys.- 
ökon.  Gesellsch.  Königsberg),  1901. 


SüB-CLASS  V 


GANOIDEI 


81 


145).  Trunk  much  laterally  compressed,  deeply  fusiform  or  cycloidal.  Ex- 
terna! bones  ornamented  with  tubercles  and  ridges  of  ganoine.  Eye  surrounded 
by  a  complete  ring  of  small  quadrangular  plates  {co),  behind  which  are  from 
five  to  eight  postorbitals  {so,  cheek- 
plates).  The  supra-temporal  plates  {st) 
also  numerous.  Operculum,  suboper- 
culum,  and  interoperculum  large, 
arranged  in  an  arch.  Preoperculum 
narrow,  almost  or  completely  covered 
by  the  postorbitals.  A  median  gular 
plate  between  the  laminar  branchiostegal 
rays.  Fin-fulcra  A-shaped,  the  two 
halves  being  f used  at  the  apex.  Pectoral 
and  pelvic  fins  small ;  dorsal  and  anal 
fins  much  extended  and  opposed  ;  caudal 
fin  slightly  forked.  Scales  on  the  middle 
of  the  flank  deeper  than  broad ;  no 
prominent  ridge  scales ;  all  the  scales 
thick  and  enamelled,  sometimes  tuber- 
culated.  The  earliest  species  in  the 
Alpine  Trias  (Seefeld,  St.  Cassian). 
Common  in  the  Lower  Lias  of  England 
and  the  Upper  Lias  of  Würtemberg 
(Boll,  Holzmaden),  Bavaria  (Banz),   '^i^l^rT^T^^fn  F^oSaiTtrinSSe" 

Northern    France    (Calvados),    {D.    pholi-    culum;   ma;,  MaxUla;    na,  Nasal;    op,  Operculum 


Fig.  145, 
Head  of  Dapedius.    ag,  Angular ;  hr,  bulai  plate 


7,  i  r\  1   1  r\  j^  \  AI  or,  Orbit ;  p.  Parietal ;  pmx,  Premaxilla ;   vt,  Post 

aOtUS,   Ag.  ;    JJ.    CaelatUS,    C^Uenst.).       Also    temporal;  sei,  Supraclavlcle ;  so,  Suborbitals  ;   so}), 

round       in       the       Gondwana       Beds       of    faÄraqualri  '''   '^^"""^"'"''    '''   Supratemporal 

India. 

Heterostrophus,  Wagner.     Lithographie  Stone  (Upper  Jurassic) ;  Bavaria. 

Cleithrolepis,  Egerton.  Hawkesbury  Formation ;  New  South  Wales. 
Karoo  Formation  ;  Orange  Eiver  Colony. 

Tetragonolepis,  Bronn  {Pleurolepis,  Quenst.).  Small  oval  or  almost  cycloidal 
fishes,  laterally  compressed,  with  small  pectoral  and  pelvic  fins.  Dorsal  and 
anal  fins  much  extended.  Scales  deepened  on  the  flank,  their  front  border 
thickened  and  forming  a  vertical  ridge.  T.  semicinäus,  Bronn,  from  Upper 
Lias,  Würtemberg  and  Bavaria.  Other  species  in  the  Upper  Lias  of  England, 
and  the  Kota  Formation  of  the  Deccan,  India. 


Family  2.     Semionotidae.     Woodward.i 

Premaxilla,  maxilla,  and  dentary  with  oUusely  conical  or  chisel-shaped  teeth  ; 
wmer,  pterygo-palatine  arch,  and  splenial  with  several  rows  of  stouter  hemispherical 
teeth.  All  fins  fringed  with  fulcra.  Caudal  fin  hemi-heterocercal  Scales  thick  and 
rhomhic.     Trias  to  Cretaceous. 

Colohodus,  Ag.  {Ästerodon,  Münst. ;  Tholodus,  Meyer ;  Dactylolepis,  Kunisch). 
Teeth  hemispherical  and  irregularly  crowded,  usually  with  a  mammiform  eleva- 

^  Quenstedt,  F.  A.,  Ueber  Lepidotus  in  Lias  e.  Tübingen,  \M1  .—Sauvage,  H.  E.,  Memoire  sur 
les  Lepidotus  maximus  et  palliatus  (Mem.  Soc.  geol.  France,  ser.  3,  vol.  I.),  1877.— Meyer,  H.  von. 
Fossile  Fische  aus  dem  Muschelkalk  (Palaeoutogr.  vol.  L),  lS50.—Dames,  W.,  Die  Ganoiden  des 
deutschen  Muschelkalks  (Palaeont.  Abhandl.  vol.  IV.),  1888.— Branco,  W.,  Ueber  eine  neue 
Lepidotus- Art  aus  dem  Wealden  (Jahrb.  k.  preuss.  geol.  Landesanst.),  1885. 

VOL.  II  G 


82 


PISCES 


CLASS I 


tion  in  the  middle  of  the  crown.  Scales  marked  with  more  or  less  parallel 
ridges,  ending  in  denticulations  at  the  hinder  border.  Common  in  the 
Muschelkalk  and  Lettenkohle. 

The  generic  names  Nephrotus,  Cenchrodus,  Omphalodus,  Hemilopas,  Meyer, 
and  Sargodon,  Plieninger  (Fig.  146),  are  applied  to  rounded 
or  chisel-shaped  teeth  from  the  Trias  and  Rhaetic. 

Lepidotus,  Ag.  {Sphaerodus,  p.p.  Ag. ;  Plesiodus,  Wagner ; 
Prolepidotus,  Michael),  (Figs.  147,  148).  Trunk  fusiform  and 
only  moderately  compressed,  covered  with  thick,  smooth,  or 
obliquely  striated  scales,  which  are  deeply  imbricating  and 
have  the  angles  of  the  overlapped  border  more  or  less 
produced.  Head  and  opercular  bones  more  or  less  enamelled, 
smooth  or  tuberculated.  Teeth  hemispherical  to  obtusely 
conical.  Successional  teeth  numerous,  the  incipient  germ  lying  exactly  in 
the  opposite  direction  to  that  of  the  functional  tooth,  thus  making  a  revolution 
of  180°  while  the  root  of  the  old  tooth  is  absorbed  and  it  prepares  to  appear 


Fio.  14(5. 

Sargodon  tomicus, 
Plien.  Rhaetic ;  Kein 
iiatli,  Würtemberg. 


Fi(!.  147. 
Lepidotus  notopteriis,  Ag.     Upper  Jurassic   J.ithographic  Stoiie) ;  yoleuhofen.     1/5  nat.  size. 

(Fig.  148,  Ä).  Fin  fulcra  very  large  and  biserial  (Fig.  148,  i>),  present  on  all 
the  fins.  Pectoral  fins  large ;  pelvic  fins  small ;  large  dorsal  fin  opposed  to 
the  pelvic  pair ;  caudal  fin  more  or  less  forked.     Ranging  from  the  Keuper 


tiM. 


4^^W 


Fig.  148. 


Lepidotus.  A,  Fragment  of  jaw  with  successional  teeth.  B,  Tooth  in  side  view  and  from  at)ove.  C,  Scale. 
Z),  Fulcral  annature  of  dorsal  tin.  /,  Fulcra  ;  x,  Unpaired  dorsal  scale  ;  y,  First  basal  scale  of  dorsal  lin  ;  z,  z', 
lateral  scales.     Nat.  size. 


to  the  Lower  Cretaceous,  some  of  the  later  species  having  the  largest,  stoutest 
teeth  and  well-developed  ring-vertebrae.  The  type  species,  L.  elvensis,  Blv. 
sp.,  common  in  the  Upper  Lias  of  Würtemberg,  Bavaria,  France,  and  England. 
L.  maximus,  Wagn.,  L.  notopteriis,  Ag.  (Fig.  147),  and  other  species  well  pre- 


I 


SUB-CLASS  V 


GANOIDEI 


83 


served  in  the  Lithographie  Stone  (Upper  Jurassic)  of  Germany  and  France. 
L.  7)ia7iteUi,  Ag.,  from  Wealden.  Also  Jurassic  of  India  and  Siberia,  and 
Cretaceous  of  Brazil. 

Family  3.     Eugnathidae.     Woodward. 

Trunk  slender,  covered  with  rhomboid  enamelled  scales.  Marginal  teeth  conical. 
Cranial  and  facial  bones  moderately  robust,  externally  enamelled,  and  opercular 
apparatus  complete.  Snout  not  produced.  Fin-rays  robust,  fulcra  conspicuous. 
Dorsal  fin  short  and  acuminate.  Vertebral  column  rarely  more  than  incomplete 
rings.     Tail  externally  homocercal  or  hemi-heterocercal.     Trias  to  Cretaceous. 

Eugnathus,  Ag.  {Heterolepidotus,  Egerton).  Cleft  of  mouth  wide,  with  large, 
conical,  pointed  laniary  teeth  and  numerous  smaller  pointed  teeth  between 
these.  Head  and  opercular  bones  smooth  or  tuberculated.  Fins  powerful, 
the  dorsal  arising  opposite  the  pelvic  pair,  stouter  and  longer  than  the  anal 
fin;  caudal  fin  forked,  externally  hemi-heterocercal.  Scales  rather  thick, 
mostly  longer  than  deep,  and  with  serrated  hinder  border.  The  type  species, 
E.  orthostomus,  Ag.,  a  slender  fish,  common  in  the  Lower  Lias  of  Lyme  Regis, 
Dorset.  Other  species  in  the  Lias,  and  ranging  upwards  to  the  Lithographie 
Stone  {E.  microlepidotus,  Ag.)  and  Purbeck  Beds. 

Caturus,  Ag.  ( Uraeus,  Ag.),  (Fig.  149).  Essentially  identical  with  Eugnathus, 
but  scales  thinner,  more  deeply  overlapping,  and  less  narrowed  near  the  ventral 


Fig.  149. 
Cahorus  elongatus,  Ag.     Upper  Jurassic  (Lithograpliic  Stone) ;  Ceriii,  Aiu,  France.     V->  »at.  size. 

border  of  the  fish.  Endoskeleton  of  trunk  usually  well  displayed  in  the  fossils, 
showing  hemi-vertebrae,  short  ribs,  and  free  neural  spines  in  the  abdominal 
region.  Ranging  from  the  Trias  to  the  Upper  Jurassic,  espeeially  fine  speei- 
mens  being  known  from  the  Lower  Lias  of  England  (C.  heterurus,  Ag.  sp.,  etc.), 
and  the  Lithographie  Stone  of  France,  Bavaria,  and  Würtemberg  {C.  furcatus, 
elongatus,  maxi7nus,  Ag.,  etc.). 

Strobilodus,  Wagner ;  Ditaxiodus,  Owen.  Large  fishes  resembling  Caturus, 
Upper  Jurassic  of  Europe. 

Callopterus,  Thiolliere.     Lithographie  Stone  of  Bavaria  and  France. 

Eurycormus,  Wagner  (Fig.  122).  Much  resembling  Caturus,  but  vertebral 
column  eonsisting  of  hemi-vertebrae,  which  become  two  similar  complete  rings 
in  the  caudal  region.  'Dentition  comparatively  feeble.  E.  speciosus,  Wagn., 
from  Lithographie  Stone,  Bavaria.  Other  species  in  Oxford  and  Kimmeridge 
Clays,  England. 


84 


PISCES 


CLASS I 


Ftycholepis,  Ag.  Head  and  opercular  bones  ornamerited  with  ridges  of 
ganoine ;  teeth  minute.  Scales  thick,  much  longer  than  deep,  externally 
marked  with  longitudinal  grooves.  P.  hollensis,  Ag.,  from  Upper  Lias  of 
England,  France,  Bavaria,  and  Würtemberg.  Other  species  in  Lower  Lias  of 
England.     Smaller  species  in  Trias  of  Raibl,  Carinthia,  and  Connecticut. 


Family  4.     Macrosemiidae. 

Marginal  teeth  styliform  ;  dorsal  fin  elongated  ;  scales  rhombic. 

OphiopsiSj  Ag.  Trunk  much  elongated  and  slender,  with  a  high  dorsal  fin 
extending  half  its  length.  Anal  fin  small.  Caudal  fin  hemi-heterocercal. 
Ranging  from  the  Muschelkalk  to  the  Purbeck  Beds.  0.  procera,  Ag.,  and 
other  species  common  in  the  Lithographie  Stone  of  Bavaria. 

Macrepistius,  Cope.  Lower  Cretaceous ;  Texas.  Eusemius,  Vetter.  Upper 
Jura ;  Bavaria. 

Notagogus,  Ag.  Trunk  elongated,  with  extended  dorsal  fin  subdivided  into 
two  parts,  the  anterior  portion  with  comparatively  widely  spaced  rays,  and 
not  deeper  than  the  posterior  portion.  Stout  ring-vertebrae.  N.  pentlandi, 
Ag.,  from  Neocomian,  Castellamare,  near  Naples.  Other  species  in  the 
Lithographie  Stone  of  Bavaria. 

Fropterus,  Ag.  As  Notagogus,  but  trunk  deeper  and  anterior  portion 
of  dorsal  fin  deeper  than  posterior  portion.     Eing-vertebrae.     Scales  almost 

six-sided,  deeper  than  long.     Jura. 

Histionotus,  Egerton.  The  back  of  the 
elongated  trunk  elevated  and  sharply  bent 
anteriorly,  a  single  long  dorsal  fin  extend- 
ing backwards  from  the  bend  almost  to 
the  caudal  fin,  which  is  deeply  forked. 
L^niserial  fulcra  on  both  paired  and  median 
fins.  Scales  of  flank  deeper  than  broad. 
H.  angularis,  Eg.,  from  the  English  Purbeck 
Beds.  Other  species  from  the  Lithographie 
Stone  of  Bavaria  and  France. 

Macrosemius,  Ag.  (Disticholepis,  Thioll.), 
(Fig.  150).  Trunk  elongated,  and  dorsal 
fin  extending  from  the  occiput  to  the 
caudal  fin,  which  is  rounded.  No  fin 
fulcra.  Jaws  and  pterygoid  with  power- 
ful  conical  or  styliform  teeth.  Scales 
thin  and  rhombic.  M.  rostratus,  Ag.,  31.  latiusculus,  Wagn.  (Fig.  150),  and 
other  species  in  the  Lithographie  Stone  of  Bavaria  and  France.  Small 
species  of  this  or  an  allied.  genus  in  the  Purbeck  Beds  of  Wiltshire  and 
the  Portlandian  of  Meuse,  France. 

Petalopfenjx,  Pictet.     Upper  Cretaceous  ;  Mount  Lebanon. 


Fig.  150. 

Macrosemius  latiusculus,  Wagn.  Head,  nat.  size. 
Upper  Jurassic  (Lithographie  8toiie) ;  Kelheim . 
ar,  Articular ;  br,  Braiichiostegal  rays ;  cl,  Cla viele ; 
d,  Dentary ;  hy,  Ceratohyal ;  mx,  Maxiila ;  o,  Orbit ; 
op,  Operculuiii ;  pa,  Parietal ;  pl,  Palatino  ;  pmx, 
Premaxilla ;  pop,  Preopereulum  ;  psph,  Para- 
sphenoid  ;  pt,  Pterygoid  ;  cju,  Quadrate  ;  sop,  Sub- 
operculum  ;  spl,  Spleuial ;  vo,  Vomer. 


Family  5.     Pholidophoridae. 

Trunk  fusiform ;  teeth  small  and  conical;  scales  rhombic  and  deeply  overlapping; 
dorsal  and  anal  fins  small ;  vertebrae  forming  complete  rings. 

Pholidopleurus,   Bronn   (Fig.  151).      Trunk   slender.      Scales   smooth,   one 


SÜB-CLASS  V 


GANOIDEI 


85 


Fig.  151. 

Pholidopleums  typus,  Bvonn.     Keuper ;  Raibl,  Carinthia. 
2/3  nat.  size  (after  Kner). 


series   short  and   very  deep   on   the   flank,  those  on   the  back  and  ventral 

region  longer  than  deep.     Dorsal  and  anal  fins  delicate,  elongated,  and  low, 

directly  opposed  on   the  hinder  part  of  the  caudal  region.      Caudal  fin  ex- 

ternally  homocercal,  slightly  forked.      Trias ;  Raibl,  Carinthia. 

Pleuropholis,  Egerton.     Upper  Jurassic  (English  Purbeck  Beds,  and  French 

and  Bavarian  Lithographie 

Stone).     P.  egertoni,  Wagn. 
Pholidophorus,     Ag.     (Figs. 

152,  153).     Body  shaped   like 

a    carp.       Scales    thin,    deeper 

than    long    on    the    flank,    en- 

amelled,    smooth    or    finely 

striated    and    serrated.      Small 

dorsal  fin  opposed  to  the  pelvic 

pair.     Caudal   fin   externally   homocercal,  deeply   forked ;    a   large,  unpaired 

dorsal  scale  often  at  its  base.  Com- 
mon in  the  Alpine  Trias  of  Raibl 
(P.  bronni,  Kner)  and  Seefeld ;  in 
the  Lias  of  Lyme  Regis  (P.  bechei, 
Ag.,  P.  lim- 
batus,  Ag.), 
Whitby,  Cal- 
vados, Wür- 
temberg,  and 
Bavaria  (P. 
germanicuSj 
Quenst.) ;  in 
the  Lithogra- 
phie Stone  of 
Bavaria  and 
France  ;  in 
the     Purbeck 


Fig.  152. 
Phali(1oj>hori(s  striolaris,  Ag.  Head,  iiat.  size.  Upper 
Jurassic  (Lithographie  Stone) ;  Bichstädt.  cl,  Clavicle  ; 
fr,  Frontal ;  iop,  Interoperculum ;  md,  Mandible  ;  mx, 
Maxiila  ;  na,  Nasal ;  op,  Operculuni ;  pa.  Parietal ;  pmx, 
Premaxilla  ;  pop,  Preoperculuni ;  psph,  Parasphenoid  ;  pt, 
Post-temporal ;  sd,  Supraclavicle  ;  so,  Snborbitals  ;  sop, 
8uboperculum. 


Pholidophorus  p^isilltis,  A^ 
Ehaetic ;  Seefeld,  Tyrol. 
Xat.  size. 


Beds  of  England  and  Lower  Jura  of  the  Black  Hills,  South  Dakota. 

Isopholis,  Zittel.     As  Pholidophorus,  but  scales  of  equal  size  and  rhombic. 
Pectoral  and  anal  fins  large.     Lithographie  Stone  of  Bavaria  and  France. 


Family  6.     Pycnodontidae.     Agassiz. 

Trunk  laterally  compressed,  very  deep,  oval.  Notochord  persistent.  Bibs,  vertebral 
arches,  and  spines  well  ossified.  Opercular  apparatus  incomplete,  with  one  or  two 
branchiostegal  rays.  Premaxilla  with  two  to  four  prehensile  front  teeth ;  maxilla 
thin,  deepened  behind,  toothless  ;  palatine  aiid  vomerine  bones  fused  together,  usually 
with  five  longitudinal  series  of  round  or  oval  grinding  teeth;  splenial  of  mandible 
large,  with  coronoid  process,  and  three,  four,  five,  or  more  rows  of  grinding  teeth  ; 
dentary  small  and  terminal,  fitting  in  a  groove  of  the  splenial,  and  bearing  two  to  four 
prehensile  front  teeth.  Branchial  arches  with  very  numerous,  closely  arranged,  bony 
filaments.  Clavicle  broadly  ovate  at  the  lower  end.  Fin  fidcra  ahsent.  Pelvic  fins 
small.  Dorsal  and  anal  fins  much  extended.  Scales  deeper  than  long,  with  a 
thickened,  ridge-like  anterior  margin.     Lower  Lias  to  Upper  Eocene. 

Gyrodus,  Ag.   (Figs.    154-157).      Trunk   completely  covered  with   scales. 


86 


PISCES 


CLASS  I 

f 


Frontal  profile  steep.  Vomero-palatine  with  five  rows  of  rounded,  bean-shaped 
teeth,  of  which  the  convex  crown  has  a  rugose  border  and  mammillated  apex ; 
the  middle  row  larger  than  the  lateral  rows.  Splenial  with  four  rows  of 
similar  teeth ;  dentary  with  three  stout  prehensile  teeth.  Caudal  fin  deeply 
forked,  symmetrical.  Common  in  the  Upper  Jurassic  (Lithographie  Stone)  of 
Solenhofen,  Eichstädt,  Kelheim,  Cerin  (Ain) ;  also  in  the  Kimmeridgian  of 
England,   France,   and   Switzerland,   in    the   Portlandian   and   Neocomian   of 


^^P^Ä 


Fig.  155. 


Gyrodus  tifanius,  Wagn.    Scale,  inner  (A) 
and  outer  {B)  aspects,  nat.  size.     Kellieini. 


Fig.  154. 

Head  of  Gyrodus  macropMhalmns,  Ag.  Upper  Jurassic 
(Lithographie  Stone) ;  Kellieini,  Bav:iria.  c,  Slime  canals  ; 
d,  Clavicle ;  eth,  Ethmoid  ;  fr,  Frontal ;  md^  Mandible  ;  j/i.>, 
Maxilla ;  0,  Orbit ;  op,  Preoperculum  ;  pa,  Parietal  ;  pfr, 
Post-frontal;  ptiu^  Premaxilla  ;  pt,  Post  -  temporal  s  ;  sc, 
Sclerotic  ring  ;  sei,  Operculuni ;  sq,  Squamosal. 

France  and  Switzerland,  and  the  Tithonian 
of  Sicily.  Some  species  from  the  Litho- 
graphie Stone  {G.  tifanius,  Wagner)  attain 
a  length  and  depth  of  1  m. 

Microdon,  Ag.  (Figs.  158,  159). 
Hinder  half  of  trunk  with  very  thin 
scales,  which  are  often  wanting.  Vomero-palatine  slender,  with  five  rows  of 
quadrate,  smooth,  and  fiattened  teeth ;  between  the  large  teeth  of  the  middle 
row  the  smaller  teeth  of  the  two  inner  lateral  rows  are  alternately  pressed 
inwards.  Splenial  with  one  row  of  large,  obliquely  quadrate,  smooth  teeth, 
which  is  fianked  inside  by  one,  outside  by  two  rows  of  smaller  teeth.  Caudal 
fin  slightly  forked,  symmetrical.     Common  in  the  Upper  Jurassic  (Lithographie 


Fig.  156. 
Gyrodus     titanius, 
Wagn.    Palatal  plate 
Avith  teeth,  nat.  size. 
Kelheim. 


FiG.  ir 


Gyrodus  titanius, 
Wagn.  Right  splenial 
with  four  rows  of 
teeth,  nat.  size.  Upper 
Jura ;  Kelheim. 


SüB-CLASS  V  GANOIDEI  87 

Stone)  of  Bavaria  and  France,  and  in  the  Purbeck  Beds  of  England.     Earliest 


i 


Fig.  158. 
Microdon  icagneri,  ThioUiere.     Upper  Jurassic  ;  Cerin,  Ain,  France.     1/3  nat.  size  (after  Thiolliere). 

fragments  in  the  Stonesfield  Slate  (Bathonian),  üxfordshire.     Also  Corallian 
and  Kimmeridgian,  Hanover  and  Switzerland. 

Mesodon,  Wagner.      As  Microdon,  but   teeth   on    vomero-palatine   in   five 


Fig.  151». 
Microdon    elegans,   Ag.      Vomeropalatine   (A),   splenials    of 
mandible  (B),  and  anterior  teeth  of  niandible,  inner  yiew  (C), 
and  outer  view  (D),  nat.  size.     Upper  Jurassic  ;  Kelheim. 


Fig.  160. 


Anomoeodiis  viuensteri,  Ay.  sp.  Man- 
dibular (splenial)  teeth  (A),  and  vomero- 
palatine teeth,  oral  aspect(£),  and  side  view 
(C),  nat.  size.    Greensand  ;  Kelheim. 


regulär  rows,  and  the  large  teeth  on  splenial  flanked  by  three  or  four  irregulär 
rows  of  smaller  teeth.  Caudal  fin  rounded  behind,  not  excavated.  M.  liassiciis, 
Egert.  sp.,  from  the  Lower  Lias  of  England,  is  the  oldest  known  Pycnodont,  the 


88  PISCES  CLASsi 

genus  ranging  upwards  to  the  Lower  Cretaceous  both  in  Europe  and  North 
America.     Fine  specimens  in  the  Lithographie  Stone  of  Bavaria  and  France. 

Mesturus,  Wagner.^  Much  resembling  Gyrodus,  but  with  more  irregulär 
teeth,  rounded  caudal  fin,  and  scales  often  united  above  and  below  by  jagged 
sutures.  M.  verrucosus,  Wagn.,  from  Lithographie  Stone  of  Bavaria.  31.  leedsi, 
Sm.  Woodw.,  represented  by  fine  specimens  displaying  osteology  from  Oxford 
Clav,  Peterborough. 

Stemmatodus,  Heckel.  Small,  resembling  Microdon.  Vomero-palatine  teeth 
in  five,  splenial  in  three  rows,  all  teeth  rounded  and  not  very  unequal  in  size. 
Lower  Cretaceous ;  Castellamare. 

Coelodus,  Heckel.  Hinder  half  of  trunk  scaleless.  Vomero-palatine  teeth 
with  one  median  row  of  large,  transversely  elongated,  smooth,  oval  teeth,  and 
two  lateral  rows  of  small  teeth.  One  row  in  the  splenial  dentition  relatively 
very  large,  its  teeth  transversely  elongated.  Caudal  fin  either  slightly  ex- 
cavated  or  convex  mesially  and  slightly  hollowed  laterally^  Lower  Cretaceous 
of  Istria,  Dalmatia,  Southern  Italy,  and  England ;  also  Cenomanian  and 
Turonian  in  Europe  and  North  America. 

Anonioeodus,  Forir  (Fig.  160).  Vomero-palatine  teeth  in  three  or  five 
longitudinal  series,  more  or  less  irregulär.  Splenial  dentition  with  one  row 
relatively  large,  the  lateral  series  more  or  less  irregulär,  and  not  reaching  the 
oral  border  of  the  bone.  A.  subclavatus,  Ag.  sp.,  from  Upper  Cretaceous, 
Maestricht.  A.  muensteri,  Ag.  sp.,  and  other  species  from  the  European 
Greensand.     Also  North  America. 

Palaeohalistum,  Blv.  Upper  Cretaceous  ;  Europe,  Asia,  and  Brazil.  Upper 
Eocene ;  Monte  Bolca. 

Pycnodus,  Ag.  Trunk  rather  elongated,  with  slender  caudal  pedicle  and 
forked  caudal  fin.  Dorsal  much  more  extended  than  the  anal  fin.  Scales 
thin,  absent  on  the  caudal  region.  Teeth  of  the  three  middle  rows  of  the 
vomero-palatine  rounded,  those  of  the  two  outer  rows  somewhat  smaller  and 
elliptical.  P.  platessus,  Blv.  sp.,  from  Upper  Eocene ;  Monte  Bolca.  Dentition 
in  the  Eocene  of  several  European  localities.  P.  r)iokattamensis,  Priem,  from 
Eocene,  Mokattam  Hills,  Egypt. 

Family  7.     Aspidorhynchidae.     Woodward.'^ 

Very  slender,  elongated  fishes,  with  enamelled  rliomhoid  scales  of  different  sizes. 
Snout  beak-like,  elongated,  and  pointed.  Maxilla  loose ;  mandihle  with  a  movable 
praemandibula  {^^ presymphysial  bone'').  Teeth  conical,  pointed.  Branchiostegal 
rays  numerous.  Notochord  with  ring-vertebrae.  Caudal  fin  externally  homocercal. 
Fin  fulcra  minute.     Bathonian  to  Upper  Cretaceous. 

Aspidorhynchus,  Ag.  (Fig.  161).  Thin,  slender  fishes,  attaining  a  metre  in 
length,  with  enamelled  ganoid  scales,  which  are  yellow  or  brown  in  colour,  more 
or  less  rugose  externally,  and  not  remarkably  thick.  Pectoral  fin  with  very 
broad  rays,  which  are  jointed  only  in  their  distal  quarter ;  no  fulcra.  Pelvic 
fin  somewhat  behind  the  middle  point  of  the  trunk.  Anal  fin  opposed  to  the 
small  dorsal  fin.  Caudal  fin  deeply  forked,  with  delicate  fulcra.  Lower  jaw 
much  shorter  than  the  snout,  which  is  formed  by  the  mesethmoid  and  pre- 

1   Woodioard,  A.  S.,  Ann.  Mag.  Nat.  Hist.  ser.  6,  vol.  XVII.  1896,  p.  1. 

'^  Reis,  0.,  lieber  Aspidorhynchus,  Belonostomus,  und  Lepidosteus  (Sitzungsb.  k.  bay.  Akad. 
Wiss.,  math.-phys.  Cl.),  1887. 


SUB-CLASS  V 


GANOIDEI 


89 


maxillae.  The  oldest  known  species  is  Ä.  crassus,  Sm.  Wood.,  from  the 
Stonesfield  Slate  (Bathonian)  of  Oxfordshire.  Well-preserved  fishes  in  the 
Lithographie  Stone  of  Bavaria  (A.  acutirostris,  Blv.  sp.)  and  France;  also  in 
the  English  Purbeck  Beds  (A.  ßsheri,  Egerton). 

Belonosfomus,  Ag.     As  above,  but  mandible  almost  as  long  as  the  snout. 
Kimmeridgian   to   Upper   Cretaceous.      Fine   skeletons   in   the  Lithographie 


Aspidorhynchus  acutirostris,  Ag.  Upper  Jurassic ;  Solenhofen.  iop,  Interoperculum ;  md,  Mandible ;  mx, 
Maxiila ;  op,  Operculum  ;  pnid,  Predentary  ;  pop,  Preoperculum  ;  pt,  Pterygoid ;  rpi,  Quadrate ;  s,  Binder 
cheek-plate  ;  so,  Suborbitals  ;  sop,  Suboperculum. 

Stone  of  Bavaria  (B.  sphyraenoides,  Ag.,  etc.)  and  the  Cretaceous  of  Europe, 
India,  Brazil,  and  Queensland. 

Family  8.     Lepidosteidae.     Bony  pikes.^ 

Trunk  elongated,  with  thick,  enamelled  rhombic  scales.  Snout  much  produced,  the 
very  long  maxilla  divided  by  a  series  of  vertical  sutures  into  several  pieces,  which  hear 
large  pointed  laniary  teeth  and  small  clustered  teeth ;  premaxilla  sliort  and  toothed. 
Vomer  double.  Vertebral  column  completely  ossified,  bent  upwards  into  the  superior  lobe 
of  the  tau;  vertebrae  opisthocoelous.  Allßns  with  biserial  fulcra.  Dorsal  and  analfins 
very  remote,  near  the  hemi-heterocercal,  rounded  caudalßn.     Tertiary  and  Recent. 

Lepidosteus,  the  only  genus  of  this  family,  survives  in  the  rivers  of  the 
southern  United  States,  Central  America,  and  Cuba.  Complete  individuals 
occur  also  in  the  Eocene  and  Lower  Miocene  of  Europe  and  North  America. 
L.  atrox,  Leidy,  from  the  Middle  Eocene. Green  River  Shales  of  Wyoming, 
attains  a  length  of  1*7  m. 


Order  5.     AMIOIDEI.     Lütken. 

Notochord  persistent,  or  vertebrae  in  various  degrees  of  ossification.  Opercular 
apparatus  always  complete,  with  lamelliform  branchiostegal  rays  and  a  welldeveloped 
gular  plate.  Teeth  pointed  or  conical  No  infraclavide.  Fulcra  present  or  absent. 
Supports  of  dorsal  and  anal  fins  equal  in  number  to  the  dermal  rays.  Caudal  fin  hemi- 
heterocercal.     Scales  very  thin,  overlapping,  rounded  or  rhombic  at  the  Kinder  border. 

The  Amioids  are  distinguished  from  the  Lepidostei  by  their  thin,  cycloid 
or  rhombic  scales,  which  are  not  articulated  with  each  other,  but  merely 
^  Eastman,  C.  R.,  Fossil  Lepidosteids  from  the  Green  Kiver  Shales  of  Wyoming  (Bull.  Mus. 
Comp.  Zool.  voL  XXXVI.  p.  67),  1900.     Also  Geol.  Mag.  [4]   vol.  VII.  p.  54,  1900. 


90 


PISCES 


CLASS  I 


overlap.  Notwithstanding  their  thinness,  however,  the  scales  exhibit  the 
characteristic  structure  of  true  ganoid  scales ;  the  base  contains  bone  cells,  the 
surface  is  covered  with  enamel.  In  many  Jurassic  genera  the  vertebral 
column  consists  of  hemi-vertebrae  or  complete  rings,  but  it  is  also  often 
completely  ossified.  Contrary  to  the  arrangement  in  certain  closely  related 
bony  fishes  (Physostomi),  the  terminal  vertebrae  are  continued  some  distance 
into  the  upper  lobe  of  the  tail. 

Only  one  genus  (Amin)  still  survives  in  the  rivers  of  the  southern  United 
States  and  Central  America.      The  order  ranges  upwards  from  the  Upper  Lias. 


Family  1.     Pachycormidae,     Dödeiiein. 
{Microlepidoti  and  Cf/clolepidoti,  Zittel.) 

Vertebral   axis  with  very  numerous  segments,  with  m'  ivithout  hemi-vertebrae. 

Ethmoid  forming  a  prominent  rostrum.     Branchiostegal  rays  very  numerous  (thirty 

^  j,  to  forty).      Neural   spines   in  abdominal 

vi<\  sp  region  separate  from  arches.     Caudal  fin 

^-(^^  ^^^^  ^-  j^^.      deeply   forked,   poweiful,    only    internally 

heterocercal.       Teeth    laterally  compressed, 

^y^ IL^y     '"lä^^         JS^MB^ß^    lanciform,  in  two  series,  the  largest  of  which 

are  set  in  alveoli.     Upper  Lias  to  Upper 
Cretaceous. 

Pachycor7Hus,   Ag.      Large,    salmon- 


Fia.  162. 

Kuthynotm  micropodiufi,  Ag.  sp.  Upper  Lias  ;  Boll. 
Würteraberg.  A,  Vertebrae  (o,  Haeinal  arclies ;  hyc, 
Hypocentrum ;  n,  Neural  arches ;  p,  Parapophyses 
plc,  Pleurocentrum  ;  sp,  Neural  spine).    B,  Scales. 


articulations.  Pectoral  fins  large 
in  front  of  the  anal ;  deeply 
forked  caudal  withelongated 
fulcra  on  each  lobe.  P. 
macropterus,  Blv.  sp.,  and 
other  species  in  the  Upper 
Lias  of  Germany,  France, 
and  England. 

Euthynotus,  Wagner 
(Heterothrissops,  Fseudo- 
thrissops,  Sauvage),  (Fig. 
162).  Hemi-vertebrae  pre- 
sent.  Fin  fulcra  minute. 
Pelvic  fins  present;  dorsal 
fin  opposed  to  much  ex- 
tended  anal  fin.  Scales 
rhombic,  rounded  at  the 
angles.  E.  speciosus,  Wagn., 
and  other  species  in  the 
Upper  Lias  of  Germany  and 
France. 

Hypsocormus,  AVagner 
(Fig.  163).     Large  fishes,  with  very  small 


shaped  fishes,  with  hemi-vertebrae  only 
in  the  caudal  region.  Operculum,  sub- 
operculum,  and  suborbitals  very  large. 
Rays  of  all  the  fins  with  distant 
pelvic  fins  absent ;  short  dorsal  fin  arising 


i'Ki. 


Hypsocormus  insignis,  Wagn.     Portion  of  trunk.     Upper  Jurassic 
(Lithographie  Stone) ;  Eichstädt,  Bavaria. 


•hombic  scales,  much  resembling 


;UB-CLASS  V 


GANOIDEI 


91 


Pacfiycormus,  but  with  larger  teeth,  small  pelvic  fins,  and  a  much  extended 
anal  fin.  Large  teeth  rounded  in  section,  of  complex  structure.  H.  insignis, 
Wagn.,  from  Lithographie  Stone  of  Bavaria.  H,  leedsi,  Sm. 
Woodw.,  from  Oxford  Clay,  Peterborough. 

Protosph?jraena,  Leidy  ^  (Erisichthe,  Felecopterus,  Cope), 
(Fig.  164).  Known  only  by  fragments  of  head  and  fins 
much  resembling  those  of  Hypsocormus,  but  teeth  laterally 
compressed,  and  snout  more  produced.  F.  ferox,  Leidy, 
and  other  species,  in  the  Upper  Cretaceous  of  Europe  and 
North  America.  The  teeth  were  wrongly  ascribed  to  Sauro- 
cephahis,  Harlan,  by  Agassi z. 


Family  2.     Amiidae.      Günther. 

Fio.  164. 

(Megaluridae,  Zittel:  HalecomorpJii,  Cope.)  Tooth  of  Proto- 

sphyraenaferoXylieidy. 

Vertebral  column  well  ossified,  and  flexed  upwards  hehind  into  HP^^/  ^ii*}^ '.  ^^^^' 
the  Upper  pari  of  the  rounded  caudal  fin.  Pleurocentra  and  hypo- 
centra  forming  complete  alternating  discs  in  pari  of  the  caudal  region,  the  alternate 
discs  bearing  the  neural  and  haemal  arches.  Teeth  powerful.  Branchiostegal  rays 
broad  and  few  ;  gular  plate  large.  Fulcra  present  or  absent.  Scales  very  thin  and 
cycloid.      Upper  Jurassic  to  Recent. 

Megalurus,  Ag.  (Figs.  165,  166).     Vertebral  column  much  produced  into 


Megalunis  elegantissimus,  Wagn.     Upper  Jurassic  ;  Solenhofen, 
Bavaria.     2/^  nat.  size. 


.•^"(^^m^^^ 


Fig.  16(5. 

Megalurus  polyspondylus,   Münst.      Upper  Jurassic ;    Kelheiin. 
A,  Portion  of  vertebral  column,  nat.  size*.    B,  Scales,  enlarged. 


Fig.  1(57. 
Amin  calva,  Linn.     Head,  from  be- 
neath.    Recent ;  Soutli  Carolina,    brs, 
Branchiostegal  rays  ;   h,  Ceratohyal ; 
jug,  Gular  plate  ;  md,  Mandible. 


the   Upper   caudal   lobe;    caudal   hemi-vertebrae    rather    elongated.      Fulcra 
present.     Dorsal   fin  considerably  extended,  arising  opposite   the  pelvic  fins, 

1  Felix,  J.,  Zeitschr.  deutsch,   geol.  Ges.  vol.  XLIl.  1890,  p.  278.  — Woodicard,  A.  Sm.,  Anu. 
Mag.  Xat.  Hist.  ser.  6,  vol.  XIII.  1894,  p.  510. 


92 


PISCES 


CLASS I 


and  reaching  the  hinder  end  of  the  anal  fin ;  caudal  fin  convex  behind,  very 
large.  Several  species  in  the  Upper  Jurassic  (Lithographie  Stone)  of  Bavaria, 
Nusplingen,  and  Cerin,  and  in  the  English  Purbeck  Beds.  M.  mawsoni,  Sm. 
Woodw.     From  Cretaceous  of  Bahia,  Brazil. 

Liodesmus,  Wag.  (Lophiurus,  Vetter).     Lithographie  Stone ;  Bavaria. 

Opsigonus,  Kramberger ;  Amiopsis,  Kner.  Lower  Jura ;  South  Dakota. 
Lower  Cretaceous  ;  Dalmatia  and  Istria. 

Amia,  Linn.  (CyduruSj  Notaeus,  Ag.),  (Fig.  167).  Fulcra  absent.  Dorsal 
fin  arising  in  front  of  the  pelvic  pair  and  extending  to  the  caudal  fin.  Living 
in  North  America ;  fossil  in  the  Upper  Eocene  and  Lower  Miocene  freshwater 
formations  of  Europe  and  North  America.  A.  (Notaeus)  longicauda,  Ag. 
(Montmartre),  A.  (Cydurus)  valenciennesi,  Ag.  (Armissan),  A.  kehreri,  Andreae 
(Messel,  near  Darmstadt),  A.  anglica,  Newton  (Isle  of  Wight). 

Pappichthys,  Cope.     Eocene  ;  North  America. 

Family  3.     Oligopleuridae,     Smith  Woodward. 

Veriebrae  well  ossified,  with  no  distind  pleurocentra  and  hypocentra.  Mouth 
Wide,  with  teeth  small  or  of  moderate  size.  Fulcra  present.  Scales  very  thin  and 
cydoid.     Upper  Jurassic  to  Upper  Cretaceous. 

Oligopleurus,  Thiolliere  (Fig.  168).  Teeth  very  small,  and  mandible 
prominent.     Vertebral  centra  not  pitted.     Dorsal  fin  short-based,  opposed  to 


Fig.  168. 

Oligopletirus  esodmts,  Thioll.     Upper  Jurassic  (Lithographie  Stone) ;  Cerin,  Ain,  France. 
1/4  nat.  size  (after  Thiolliere). 

anal  fin.  Caudal  fin  slightly  forked.  Scales  rather  large.  0.  esocinus,  Thioll., 
from  Lithographie  Stone,  Cerin  (Ain,  France).  Other  species  in  English 
Wealden  and  Purbeck  Beds. 

Oenoscopus,  Costa  (AttaJceopsis,  Thioll.  ;  Macrorhipis,  Wagn.).  Almost  as 
above,  but  vertebral  centra  with  two  lateral  pits,  and  greater  portion  of  dorsal 
in  advance  of  anal  fin.  0.  petraroiae,  Costa,  from  Lower  Cretaceous,  Pietraroja, 
Prov.  Benevento,  Italy.  Other  species  in  French  and  German  Lithographie 
Stone. 

Spathiurus,  Davis.  With  much  extended  dorsal  fin.  Upper  Cretaceous ; 
Mount  Lebanon. 


Sub-Class  6.      TELEOSTEI.^     Bony  fishes. 

Skin  with  thin,  elastic,  cydoid  or  ctenoid  scales,  rarely  with  bony  plates.    Vertebral 
column  ossified  ;  tail  internally  and  externally  homocercal.    Intermuscular  bones  more 

^  Bassani,  Fr.,  Descrizione  dei  pesci  fossili  di  Lesina  accorapagnata  da  appunti  su  alcune  altre 
ittiofaune  cretacee  (Denksclir.  k.  Akad.  Wiss.  Wien,  math.-naturw.  Cl.  vol.  XLV.),  1882.—K7ier,  R., 
Ueber  einige  fossile  Fische  aus  Kreide  und  Tertiärschichten  von  Comen  und  Podsuded  (Sitzungsb. 


I 


süB-CLASs  VI  TELEOSTEI  93 

or  less  numerous.  Fin  fulcra  absent.  In  the  living  forms — optic  nerves  completely 
decussating,  conus  mieriosus  of  the  heart  with  only  two  valves,  and  intestine  without  a 
Spiral  valve. 

The  distinction  between  the  bony  fishes  and  ganoids  consists  partly  in  the 
dermal  skeleton  and  partly  in  anatomical  characters,  which  cannot  usually  be 
verified  by  palaeontologists.  The  two  sub-classes  are  most  closely  related  to 
each  other,  and  the  line  of  demarcation  between  the  Amioidei  and  the  Physo- 
stomi  is  often  almost  obliterated.  This  applies  specially  to  the  scales,  which 
have  already  become  thin  and  elastic  in  the  former,  and  are  not  distinguishable 
in  any  respect  from  those  of  certain  Physostomi,  in  which  a  thin  calcified 
layer  with  bone  cells  happens  to  be  developed  beneath  the  outer  smooth  layer. 
Among  Teleostei  the  internal  skeleton  is  often  characterised  by  its  very  dense 
structure  and  the  sparse  development  of  bone  cells.  The  caudal  fin,  unlike 
that  of  the  ganoids,  is  usually  both  internally  and  externally  homocercal.  In 
the  more  specialised  forms  the  pelvic  fins  are  sometimes  displaced  far  forwards, 
while  the  rays  of  the  dorsal  fins  are  sometimes  articulated,  sometimes  spinous, 

The  Teleostei  are  divided  into  the  two  Orders  of  Physostomi  and 
Physoclysti. 

Order  1.     PHYSOSTOMI.     Müller. 

Air  bladder,  when  present,  connected  by  a  tube  with  the  Oesophagus.  Pelvic  fins 
abdominal ;  all  fin  rays  articulated,  except  the  foremost  rays  of  the  pectoral  and  dorsal 
fins,  lühich  are  sometimes  spinous.     Scales,  when  present,  usually  cycloid. 

Of  all  the  bony  fishes  the  Physostomi  approach  most  closely  the  ganoids, 
especially  the  Amioidei.  They  probably  originated  from  the  latter  in  the  Trias, 
becoming  specialised  in  their  own  line,  and  soon  considerably  exceeding  their 
ancestors  in  diversity  of  form.  They  already  exhibit  an  important  develop- 
ment in  the  Upper  Jurassic  and  Lower  Cretaceous,  but  attain  their  widest 
distribution  in  the  Tertiary  and  at  the  present  day.  They  live  partly  in  the 
sea,  partly  in  fresh-waters. 

Family  1.     Leptolepidae.     Smith  Woodward. 

Trunk  elegantly  fusiform.  Head  with  delicate  membrane  bones  and  well-developed 
check  plates,  more  or  less  enamelled  ;  parietals  meeting  in  middle  line,  flanked  by  large 
squamosals  ;  premaxilla  very  small ;  maxilla  large,  entering  the  gape,  loosely  attached 
and  with  two  supramaxillaries ;  teeth  small  and  conical.  Opercular  apparatus 
complete.  A  Single  dorsal  fin.  Scales  ganoid  and  with  bony  layer.  Upper  Lias  to 
Lower  Cretaceous. 

Leptolepis,  Ag.  (Tharsis,  Giebel),  (Figs.  169,  170).  Usually  small  fishes. 
Dorsal  fin  in  front  of  anal  fin,  which  is  not  much  extended.  Dentary  bone 
sharply  rising  into  a  thickened  obtuse  elevation  near  its  anterior  end.     Teeth 

k.  Akad.  Wiss.  Wien,  matli.-naturw.  Cl.  vols.  XLVIII.,  LVI.).— Äwer  and  Steindachner,  Neue 
Beiträge  zur  Kenntniss  der  fossilen  Fische  Oesterreichs  (Denkschr.  Akad.  Wien,  vol.  XXL),  1863. 
—Kramherger,  D.  G.,  Die  eocänen  Fische  der  Baschker  Schichten  (Palaeontogr.  vol.  XXIV.).— Die 
jungtertiäre  Fischfauna  Croatiens,  I.,  II.  (Beitr.  Palaeont.  Oesterr. -Ungarns,  vols.  IL,  III.),  1882-83. 
—Meyer,  H.  v.,  Palaeontogr.  vols.  IL,  YL— Sauvage,  H.  E.,  Bull.  Soc.  geol.  France,  ser.  3,  vols. 
IL,  IIL,  VL,  XI.— Steindachner,  F.,  Beiträge  zur  Kenntniss  der  fossilen  Fischfauna  Oesterreichs, 
I.-IV.  (Sitzungsb.  Akad.  Wien,  vols.  XXXVIL,  XXXVIIL,  XL.,  XLVIL),  1859-63.  — Wettstein,  A 
Ueber  die  Fischfauna  des  tertiären  Glarnerschiefers  (Abh.  Schweiz,  palaeont.  Ges.  vol.  XIIL),  1886. 


94 


PISCES' 


CLASS I 


minute.  L.  bronni,  Ag.j  and  other  comparatively  small  species  in  the  Upper 
Lias  of  England,  France,  and  Germany.  L.  diihius,  Blv.  sp.,  L.  spraftiforniis, 
Ag.  (Fig.  170),  and  other  species  in  the  Upper  Jurassic  (Lithographie  Stoiie) 


Fig.  1(59. 

Head  of  Leptolepis  knorri,  Ag.     Upper 
Jurassic ;  Kelheim.    Reduced. 


sprattifonnis,  Ag. 
Bavaria. 


Upper  Jurassic  ;  Eichstädt, 
Nat.  size. 


of  Bavaria  and  France ;  also  from  the  English  Purbeck  Beds,  the  Lower 
Cretaceous  of  the  Isle  of  Lesina,  Dalmatia,  and  the  Wianamatta  Formation  of 
New  South  Wales.     Fragments  from  King  Charles  Land,  Spitzbergen. 

Thrissops,  Ag.  Sometimes  attaining  rather  large  size.  The  short  dorsal  fin 
opposed  to  the  much  extended  anal  fin.  Ribs  very  stout.  Upper  Jurassic 
and  Lower  Cretaceous  of  Europe,  the  type  species  being  T.formosus,  Ag.,  from 
the  Bavarian  Lithographie  Stone. 

Aethalion,  Münster.     Lithographie  Stone  ;  Bavaria. 


Family  2.     Elopidae. 

Trunk  fusiform,  and  caudal  region  relatively  short.  Head  with  well-developed 
cheek  plates,  not  enamelled ;  jaws  as  in  Clupeidae.  Opercular  apparatus  complete, 
with  numerous  hranchiostegal  rays,  and  usually  a  gular  plate.  Ä  Single  dorsal  fin, 
without  adipose  dorsal.  Scales  thin  and  cycloid,  without  bony  layer.  Lower 
Cretaceous  to  Recent. 

Elopopsis,  Heckel.  Gape  of  niouth  wide,  with  large  teeth.  E.  fenzli, 
Heckel,  from  Neocomian,  Comen,  Istria.  E.  ziegleri,  v.  d.  Marck,  and  other 
species  in  the  Upper  Cretaceous  of  Europe. 

Osmeroides,  Ag.  (Rhabdolepis,  v.  d.  Marck  non  Troschel ;  Holcolepis,  v.  d. 
Marck).  Salmon-shaped  fishes  with  minute  clustered  teeth,  and  very  deeply 
overlapping  scales.  0.  lewesiensis,  Mantell  sp.,  from  English  Chalk.  Other 
species  in  the  Upper  Cretaceous  of  Westphalia  and  Mount  Lebanon. 

Thrissopater,  Günther.  Gault ;  Folkestone.  Fachyrhizodus,  Dixon  {Hypsodmi, 
Ag.).     Upper  Cretaceous;  Europe  and  North  America. 

Bhacolepis,  Ag.  Upper  Cretaceous  ;  Brazil.  Megalops,  Lacep. ;  Elops,  Linn. 
Eocene  to  Recent. 

Family  3.     Albulidae. 

Clupeoids  with  very  small  mouth,  arul  some  inner  bones  with  grinding  teeth. 
Branchiostegal  rays  few,  and  gular  plate  absent.     Upper  Cretaceous  to  Recent. 

Istieus,  Ag.  An  elongate  fish,  with  much  extended  dorsal  fin,  small  anal 
fin,  and  forked  tail.  Teeth  very  small.  Closely  resembling  the  existing  deep- 
sea  fish,  Bathythrissa,  Günther.  About  three  species  in  the  Upper  Cretaceous 
of  Westphalia  and  Syria. 


SÜB-CLASS  VI 


TELEOSTEI 


95 


Fisodus,  Owen.  Large  hemispherical  or  flattened  crushing  teeth  on  the 
parasphenoid.  Closely  resembling  existing  Alhula.  Lower  and  Middle  Eocene 
of  England  and  Belgium. 


Family  4.     Ichthyodectidae.     Crook.i 

Large  extind  predaceous  fishes,  with  a  row  of  strong  conical  teeth  fixed  in  sockets 
on  the  margin  of  the  jaws.  Upper  jaw  formed  hy  short  and  deep  preniaxilla,  and 
long  stout  maxilla ;  mandihle  deep,  truncated  in  front,  without  any  presymphysial 
hone.  Vomer  and  parasphenoid  toothless ;  palato-pterygoid  arch  with  patches  of 
small  teeth.  Paired  fins  composed  of  a  very  hroad,  anterior,  and  numerous  narrower 
rays,  finely  divided  and  articulated  quite  at  the  distal  end.  Dorsal  fin  short  and 
remote  ;  anal  fin  not  much  extended  ;  caudal  fin  forked,     Cretaceous. 

This  family  is  very  closely  related  to  the  existing  Chirocentridae,  of  which 
only  one  genus  (Chiro- 
centrus)  is  known,  in- 
habiting    the    Indian 
Ocean. 

Fortheus,  Cope 
(Xiphactinus,  Leidy  ; 
Hi/psodon,  Ag.  p.p.), 
(Fig.  171).  Po  werf  ul 
iishes,  sometimes  of 
gigantic  size.  Teeth 
of  variable  size,  oval 
in  transverse  section. 
Palatine  movably 
articulated  with  eth- 
moid,  with  hammer- 
shaped  thickening. 
Eye  with  ossified 
sclerotic ;  three  sub- 
orbital plates.  Oper- 
culum  well  developed 
and  large.  F.  molossus, 
Cope  (Fig.  171),  and 
other  species  occur  in 
the  Chalk  of  Kansas,  U.S.A.  F.  mantelli,  Newton,  and  other  species  in  the 
Chalk  and  Gault  of  England,  France,  Belgium,  Bohemia,  and  Saxony. 
Fragments  also  in  Cretaceous  of  Rolling  Downs,  Queensland. 

Ichthyodedes,  Cope.  As  Fortheus,  but  smaller,  and  teeth  of  uniform  size. 
Chalk  of  Kansas  and  England. 

Gillicus,  Hay.  Like  the  preceding,  but  teeth  small  and  fringe-like. 
Upper  Cretaceous ;  Kansas. 

Spathodactylus,  Pictet.  Type  specimen  displaying  fins.  Neocomian  : 
Voirons,  Switzerland. 

^  Crook,  A.  R.,  Ueber  einige  Knoclienfische  aus  der  mittleren  Ki-eide  von  Kansas  (Palaeoutogr. 
vol.  XXXIX.),   1892. — Loomis,   F.   B.,  Die  Anatomie  und  die  Verwandtschaft  der  Ganoid  und 
Knochenfische  aus  der  Kreide  von  Kansas  (Palaeoutogr.  vol.  XLVL),  1900. 
of  the  Upper  Cretaceous  (Univ.  Geol.  Surv.  Kansas,  vol. .VI.),  1900. 


Head  of  Porthms  molosms,  Cope.     Niobrara  Cretaceous  ;  Fox  Cafton, 
Kansas.     V4  '^at.  size  (after  Cope). 


-Steivart,  A.,  Teleosts 


96 


PISCES 


CLASS I 


Family  5.     Saurodontidae.     Cope  (non  Zittel). 

Skull  laterally  compressed  ;  jaws  poweiful,  and  bearing  a  single  row  of  compressed, 
hiife-like  teeth,  with  nutrient  foramina  or  notches  helow  the  internal  alveolar  border  ; 
a  presymphysial  bone  present  and  without  teeth,     Cretaceous. 

The  two  genera  constituting  this  faimily,  ßaurocephalus,  Harlan  (non  Ag.), 
and  Saurodon,  Hays  (Daptinus,  Cope),  difFer  from  the  Ichthyodedidae  in  the 
presence  of  a  presymphysial  bone  and  in  the  form  and  manner  of  succession 
of  teeth.  In  the  first-named  genus  the  cr(^ns  of  the  teeth  are  short  and 
compressed,  with  nutrient  foramina  below  the  alveolar  border  on  the  inner 
face  of  the  jaw ;  and  in  Saurodon  the  inner  margin  of  each  dental  alveolus 
is  deeply  notched.     Upper  Cretaceous  ;  New  Jersey  and  Kansas. 


Family  6.     Olupeidae.     Herrings. 

Trunk  elegantly  fusiform.  Supraoccipital  bone  separating  parietals,  and  otic' 
region  prominent;  cheek  plates  reduced ;  premaxilla  very  small ;  maxilla  large, 
entering  the  gape,  loith  two  supramaxillaries  ;  dentition  feeble.  Opercular  apparatus 
complete,  but  few  branchiostegal  rays,  and  no  gular  plate.  A  single  dorsal  ßn,  nearly 
median,  without  adipose  dorsal.  Scales  thin  and  cycloid,  without  bony  layer.  Lower 
Cretaceous  to  Recent. 

Diplomystus,  Cope.     Abdomen  compressed  to  a  sharp  edge,  and  bordered 

with  large  ridge  scutes ;  back  between  the   occiput  and  dorsal  fin  armoured 

with  smaller  ridge  scutes.     D.  dentatus,  Cope,  and  other  species  finely  preserved 

in  the  Eocene  Green  River  Shales  of   Wyoming,  U.S.A.     Smaller  species  in 

the  Upper  Cretaceous 
of  Mount  Lebanon 
(B.  brevissimus,  Blv. 
sp.)  and  Brazil,  and  in 
the  Oligocene  of  the 
Isle  of  Wight.  Living 
in  the  rivers  of  New 
South  Wales  and 
Chili. 

Scombroclupea, 

Kner.     As  Clupea,  but  finlets  spaced   out   between  the  small  anal   and  the 

forked    caudal   fin. 

S.      macrophthalma, 

Heckel     sp.,     from 

Upper     Cretaceous 

of  Mount  Lebanon 

and  Comen,  Istria. 
Clupea,    Linn. 

Herrings.       (Fig. 

172.)      Abdomen 

compressed     to     a 

sharp    edge,    and 


Fig.  172. 

Clupea  ventricosa,  H.  v.  Meyer.     Lower  Miocene  ;  Unterkirchberg, 
near  Ulm,  Würtemberg. 


Fig.  173. 
Mcletta  sardinitea,  Heckel.     Lower  Oligocene 


bordered  with  large  ridge  scutes ;    no  dorsal   scutes. 
jaws  and  palatines,  larger  on  the  vomer  and  hyoid. 


Radoboj,  Croatia  (after  Heckel). 

Teeth  minute  on  the 
Dorsal  fin  small  and 


SÜB-CLASS  VI  TELEOSTEI  97 

median.  Not  certainly  known  below  the  Upper  Eocene  of  Monte  Bolca,  near 
Verona.  Small  species  in  the  freshwater  Lower  Miocene  of  Unterkirchberg, 
near  Ulm,  Würtemberg. 

Alosa,  Engraulis,  Ciiv.     Tertiary  and  Recent. 

Meletta,  Val.  (Fig.  173).  Small  slender  fishes  with  thick  cycloid  scales, 
which  are  marked  with  three  to  six  pairs  of  radiating  grooves.  Jaws  tooth- 
less.  Ventral  ridge  scutes  large.  Tertiary  and  Recent.  Very  common  in 
the  Lower  Oligocene  (Melettaschiefer)  of  the  Carpathians,  Croatia,  Glarus, 
Alsace,  etc. 

Family  7.     Salmonidae.     Salmon. 

As  Clupeidae,  but  a  small  adipose  fin  behind  the  dorsal  fin.  Upper  Tertiary 
and  Recent. 

Fossil  skeletons  of  the  existing  Mallotus  viUosus,  Müll.,  are  very  common  in 
nodules  in  Pleistocene  Clay  on  the  coast  of  Greenland  and  in  the  glacial 
deposits  of  Canada. 

Family  8.     Osteoglossidae. 

Head  bones  much  ihickened,  and  cheek  plates  robust.  Margin  of  upper  jaw  formed 
both  by  premaxilla  and  maxilla.  Scales  large  and  thick,  composed  of  mosaic-like 
pieces.     Upper  Cretaceous  to  Recent. 

Phareodus,  Leidy  (Dapedoglossus,  Cope).  Laterally  compressed  deep-bodied 
fishes  from  the  Eocene  Green  River  Shales  of  Wyoming,  U.S.A. 

(?)  Brychaetus,  Ag.  London  Clay ;  Sheppey.  Plethodus,  Dixon.  Cre- 
taceous ;  England.     Anogmius,  Cope.     Upper  Cretaceous ;  Kansas. 

Osteoglossum  and  other  genera  are  large  freshwater  fishes  living  in  the 
tropics. 

Family  9.     Halosauridae.     Günther. 

Eel-shaped  fishes  with  pectoral  and  pelvic  fins,  a  short  dorsal  fin,  an  extended  anal 
fin  usually  confluent  with  the  diminutive  caudal,  and  both  head  and  trunk  covered  with 
cycloid  scales.  Margin  of  upper  jaw  formed  both  by  premaxilla  and  maxilla.  Verte- 
bral  centra  as  delicate  cylinders.  Lateral  line  ivith  luminous  organs  along  the  ventral 
border  of  the  flank.     Upper  Cretaceous  to  Recent. 

Halosaurus,  Johnson,  living  at  great  depths  in  the  ocean.  Echidnocephalus, 
W.  von  der  Marck,  an  almost  identical  genus  from  the  Upper  Cretaceous  of 
Sendenhorst,  Westphalia. 

Family  10.     Dercetidae.     Smith  Wood  ward  {Hoplopleuridae,  Pictet  p.p.). 

Eel-shaped  fishes  with  pectoral  and  pelvic  fins,  a  more  or  less  extended  dorsal  fin, 
and  separate  anal  and  caudal  fins.  Parietal  bones  large  and  in  contact  mesially  ; 
premaxilla  forming  margin  of  upper  jaw.  Vertebral  centra  as  delicate  cylinders,  with 
transverse  processes  bearing  the  ribs.  No  overlapping  scales  ;  but  paired  longitudinal 
series  of  bony  scutes.     Cretaceous. 

Dercetis,  Agassiz.  Snout  elongated  and  pointed ;  teeth  minute  and 
clustered.  Dorsal  fin  occupying  greater  part  of  back,  and  pelvic  fins  inserted 
opposite  to  it ;  anal  fin  short,  opposite  hinder  end  of  dorsal ;  caudal  fin  forked. 
Dermal  scutes  more  or  less  angulated  and  ornamented  with  tubercles  or  spines  ; 


VOL.  II 


H 


98 


PISCES 


CLASS  I 


two  dorsal  series,  two  ventral  series,  and  a  paired  series  supporting  the  lateral 
line.     D.  scutatus,  Ag.     Upper  Cretaceous ;  Westphalia. 

LeptotracheluSj  W.  v.  d.  Marck  (Triaenaspis,  Cope).  As  Dercetis,  but  dorsal 
fin  not  occupying  more  than  middle  third  of  back,  and  anal  fin  behind  it. 
L.  triqueter,  Pict.  sp.,  and  other  species  from  the  Cretaceous  of  the  Lebanon, 
AVestphalia,  and  South  Dakota,  Ü.S.A.  L.  lewesiensis,  Mant.  sp.,  from  English 
Chalk. 

Pelargorhynchus,  v.  d.  Marck.     Upper  Cretaceous  ;  Westphalia. 

Stratodus,  Cope.  Premaxilla  short,  with  several  rows  of  teeth ;  palatine 
and  mandibular  teeth  large,  numerous,  in  several  rows,  all  with  pulp  cavity. 
Upper  Cretaceous ;  Kansas. 


Family  11.     Enchodontidae.     Smith  Woodwaid  (Hoplopleuridae,  Pictet  p.p.). 


Bapacious  fishes  with  more  or  less  fusiform  trmik.  Parietal  bones  very  small, 
separated  hy  the  supraoccipital ;  delicate  premaxilla  extended  and  nearly  exduding  the 
rod-like  maxilla  from  the  rnargin  of  the  upper  jaw,  which  bears  very  small  teeth ; 
yowerful  teeth  ßised  with  the  palato-pterygoid  and  dentary  bones.  Vertebral  centra 
robust,  none  with  transverse  processes.  A  small  adipose  fin  probably  present  behind 
the  Single  dorsal  fin.  No  scales  ;  but  a  median  series  of  dorsal  bony  scutes,  and  often 
a  paired  series  of  similar  scutes  supporting  the  lateral  line.     Cretaceous. 

Enchodus,  Ag.  (Eurygnathus,  Davis ;  Ischyrocephalus,  v.  d.  Marck ;  Holcodon, 
Kramb.),  (Fig.  174).     The  largest  and  longest  tooth  at  the  anterior  end  of.the 

palatine;  large  teeth  of 
dentary  spaced,  increas- 
ing  in  length  to  the  Sym- 
physis. External  bones 
more  or  less  tuberculated. 
Three  or  four  oval  median 
scutes  between  the  occiput 
and  dorsal  fin  ;  an  adipose 
dorsal  on  the  tail ;  caudal 
fin  forked.  No  postclavi- 
cular  plate ;  no  scutes 
along  course  of  lateral  line,  but  a  recurved  hooklet  on  each  side  of  the  caudal 
pedicle.  E.  lewesiensis,  Mant.  sp.,  from  the  Lower  Chalk,  S.-E.  England. 
Well-preserved  skeletons  of  other  species  in  the  Upper  Cretaceous  of  West- 
phalia and  the  Lebanon.  Fragments  in  the  Upper  Cretaceous  of  North 
America,  and  Maastricht  Beds,  Holland. 

Eurypholis,  Pictet  {Sawvrhamphus,  Heckel).  As  Enchodus,  but  a  large 
postclavicular  plate,  and  well-developed  scutes  along  the  course  of  the  lateral 
line.  E.  boissieri,  Pictet,  from  Upper  Cretaceous  of  Hakel,  Mount  Lebanon. 
An  imperfectly  known  species,  erroneously  restored  by  Heckel  under  the  name 
of  Saurorhainphus  freyeri,  Heck.,  from  Lower  Cretaceous,  Comen,  Istria. 

Cimolichthys,  Leidj".  Largest  teeth  in  middle  of  palato-pterygoid  arcade 
semi-barbed  at  apex.  Clustered  teeth  in  mandible,  with  simply  pointed  larger 
teeth  at  intervals.  C.  lewesiensis,  Leidy,  from  Lower  Chalk,  S.-E.  England. 
The  semi-barbed  teeth  common  in  the  European  Chalk,  known  also  in  North 
America. 

Prionolepis,  Egert.;  Leptecodon,  Williston.     Upper  Cretaceous. 


Imperfect  dentary  bone  of  Enchodus  lewesiensis,  Mant. 
Lower  Clialk  ;  Lewes  (after  Agassiz). 


süß-CLASS  VI  TELEOSTEI  99 

Halec,  Ag.  (Pornognathus,  Dixon ;  Archaeogadus,  v.  d.  Marck).  Premaxilla 
very  slender,  with  minute  teeth  ;  maxilla  equally  slender,  with  a  few  relatively 
large  spaced  teeth  at  its  hinder  end.  Palato-pterygoid  teeth  closely  arranged, 
laterally  compressed  cones,  largest  in  the  middle  of  the  arcade.  No  dermal 
scutes,  except  a  pair  of  recurved  hooklets  oii  the  caudal  pedicle.  H.  eupterygius, 
Dixon,  well  preserved  in  Lower  Chalk,  S.-E.  England.  Halec  sternbergi, 
Ag.,  in  Turonian,  Bohemia.  Other  species  in  Upper  Cretaceous,  Mount 
Lebanon,  and  in  Lower  Cretaceous,  Isle  of  Lesina,  Dalmatia. 

Empo,  Cope.  Double  series  of  teeth  on  palatine,  none  barbed.  Premaxilla 
elongate,  with  one  row  of  small  teeth ;  mandibular  teeth  in  two  series,  of 
which  the  outer  are  small  and  in  several  rows,  while  the  inner  are  very  large. 
Upper  Cretaceous  of  Kansas  and  S.-E.  England. 

Family  12.     Scopelidae. 

Premaxilla  much  extended,  exdudiug  maxilla  from  upper  margin  of  mouth. 
Skull  and  skeleton  as  in  Enchodontidae.  A  small  adipose  fin  behind  the  dorsal  fin. 
No  air  bladder.  Trunk  naked  or  scali/,  without  bony  scutes.  Cretaceous  to 
Recent. 

Exclusively  marine  fishes,  for  the  most  part  pelagic  or  deep-sea  forms. 

Sardinioides,  v.  d.  Marck.  Teeth  minute ;  maxilla  expanded  behind. 
Dorsal  fin  median  ;  paired  fins  small ;  caudal  fin  slightly  forked.  Scales  large, 
serrated  at  the  hinder  border.  S.  monasteri,  Ag.  sp.,  from  Upper  Cretaceous, 
Sendenhorst,  Westphalia.     Other  species  from  Mount  Lebanon. 

Sardinius,  v.  d.  Marck.  Upper  Cretaceous;  Westphalia.  Leptosomus,  v.  d. 
Marck.  Upper  Cretaceous  ;  Westphalia  and  Mount  Lebanon.  Opisthopteryx^ 
Pictet  and  Humb.     Lebanon. 

Scopeloides,  Wettstein.     Upper  Eocene  ;  Canton  Glarus. 

Parascopelus,  Anapterus,  Sauvage.     Upper  Miocene ;  Licata,  Sicily. 

PJiinellus,  Ag.  {Ichthyotringa,  Cope),  (Fig.  175).  Slender  fishes  with  very 
large  pectoral  fins,  and  the  premaxillae  produced  forwards  into  a  long  pointed 


Fio.  175. 
Rhinellus  fiircatus,  Ag.     Upper  Cretaceous  ;  Sendenhorst,  Westphalia  (after  W.  v.  d.  Marek). 

rostrum.  Teeth  slender  and  pointed.  Dorsal  fin  small,  in  advance  of  the 
still  smaller  anal  fin  ;  caudal  fin  forked.  Scales  smooth,  slightly  enlarged 
along  the  course  of  the  lateral  line.  Upper  Cretaceous ;  AVestphalia,  Mount 
Lebanon,  and  Dakota. 


100 


PISCES 


CLASS  I 


Family  13.     Gonorhynchidae. 

Fremaxilla  smaller  than  maxilla,  hut  excluding  latter  from  margin  of  upper  jaw. 
No  adipose  dorsal  fin.  No  air  hladder.  Scales  deeply  overlapping^  fringed  behind 
with  short  spines.     Cretaceous  to  Recent. 

Gharitosomus,  W.  v.  d.  Marck.  Upper  Cretaceous ;  Westphalia  and 
Lebanon. 

Notogoneus,  Cope  (Sphenolepis,  Ag.).  Freshwater  Eocene  (Green  River 
Shales) ;  Wyoming,  U.S.  A.     Upper  Eocene  ;  France  and  Germany. 


Cheirothricidae. 


Smith  Woodward. 
Abdominal  vertebrae  with  trans- 


Family  14. 

Scopeloids  with  enormously  enlarged  pelvic  fins. 
verse  processes.     Cretaceous. 

Cheirothrix,  Pictet  and  Humbert  (Megapus,  Schlüter ;  Älegistopus,  Landois). 
Branchiostegal  rays  very  large,  eight  or  nine  in  number.  Pectoral  fins  compara- 
tively  small  and  delicate,  with  only  one  ray  considerably  elongated ;  the  enlarged 
pelvic  fins  close  to  the  pectorals,  with  about  seventeen  rays ;  dorsal  fin  deep, 
arising  immediately  behind  the  head ;  anal  fin  small ;  caudal  fin  forked.  C. 
libanicus,  P.  and  H.,  from  Upper  Cretaceous,  Mount  Lebanon.  G.  guestphalicus, 
Schlüter  sp.,  from  Westphalia. 


Family  15.     Esocidae.     Pikes. 

Trunk  elongated,  with  large  cydoid  scales.  Fremaxilla  and  maxilla  entering 
Upper  border  of  mouth.  Fremaxilla,  mandible,  palatine,  and  vomer  with  stout, 
pointid  teeth  ;  maxilla  toothless.     Dorsal  fin  remote.     Miocene  to  Recent. 

Fine  specimens  referable  to  the  existing  genus  Esox,  Cuv.,  occur  at 
Oeningen  and  in  other  Miocene  freshwater  formations  in  Europe. 


Family  16.     Oyprinodontidae.     Toothed  carps. 

Small  freshwater  fishes  with  cydoid  scales.  Fremaxilla  excluding  maxilla  from 
Upper  margin  of  mouth;  no  barbels.  Margin  of 
jaws  and  pharyngeal  bones  with  pointed  teeth.  No 
anterior  vertebrae  fused  together.  No  adipose  dorsal 
fin.     Tertiary  and  Recent. 

Of  the  genera  of  this  family,  Frolebias,  Sauvage, 
i.Ma.  .uyeri,  ig.' ' morineiia-ciay ;     ^lUed  to  Lcbias,  Cuv.  (Fig.  176),  is  rcmarkably  com- 
Frankfurt-a.-M.   Nat.  size.  mon  in  the  Oligoccne  and  Miocene  of  Europe. 


Family  17.     Oyprinidae.     Carps. 

Freshwater  fishes  with  cydoid  scales.  Fremaxilla  excluding  maxilla  from  upper 
margin  of  mouth ;  barbels  present  or  absent.  Mouth  toothless,  but  lower  pharyngeals 
falciform  and  bearing  one  to  three  rows  of  hollow  prehensile  teeth.  Usually  only  three 
Iranchiostegal  rays.  Anterior  vertebrae  fused  together,  and  air  bladder  connected 
with  organ  of  hearing  by  a  chain  of  ossicles.     Upper  Tertiary  and  Recent. 

The  Cyprinoids  are  numerous  in  the  fresh-waters  of  the  Old  World  and 


SÜB-CLASS  VI 


TELEOSTEI 


I 


North  America,  but  do  not  occur  in  South  America. 

fossil  species,  all  from  fresh- 

water    formations,    belong 

to     the     existing     genera 

Leuciscus,  Klein  (Fig.  177), 

Tinea,  Gobio,  Barbus,  Cuv., 

Bhodeus,  Aspius,  Ag.  (Fig. 

178),    Cyprinus,    Cobitis 

(Artedi),  Linn.,  Nemachilus, 

Cuv.,  Thynnichthys,  Bleeker, 

etc.       The     only    extinct 

genera,    such    as    Amyzon, 

DiastichuS,  Oligobelus,  Cope,  Scales  of  Leudscus  oeningensls,  Ag. 
r,^A  ^^-V.^«^  ^«^  1  1  Upper  Miocene ;  Oeningen,  Baden, 
and      Others,       are      closely     Enlarged  (after  Winkler). 

related  to  existing  forms. 


101 


Most  of  the  known 


Fio.  177. 


Pharyngeal  bones  and 
teeth  of  Aspius  rapax,  Ag. 
Recent  (after  Heckel  and 
Kner). 


Family  18.     Siluridae.     Cat-fishes. 

Scaleless  fishes,  naked  or  armoured  with  bony  plates.  Premaxilla  exduding 
maxilla  from  upper  riiargin  of  mouth,  the  rudimentary  maxilla  usually  supporting  a 
barbel.  Suboperculum  absent.  Infraclavicular  plates  present.  Anterior  pedoral  fin 
ray  usually  a  strong  bony  spine.  Anterior  vertebrae  and  air  bladder  as  in  Cyprinidae. 
Eocene  to  Recent. 

The  Siluroids  form  a  very  numerous  family  of  freshwater  fishes,  ranging 
over  all  temperate  and  tropical  regions,  and  a  few  sometimes  passing  into  the 
sea  round  the  coasts.  Fossil  remains  are  rare,  and  represent  fishes  closely 
resembling  those  still  surviving.  The  oldest  known  fragment  is  a  portion  of 
head  (Bucklandium  diluvii,  König)  from  the  London  Clay  of  Sheppey.  Typical 
remains  of  Arius  occur  in  the  Middle  and  Upper  Eocene  of  the  Hampshire 
Basin  and  Belgium.  Other  genera  are  recorded  from  the  Eocene  of  Wyoming, 
U.S.A.  (Bhineastes,  Cope),  the  Lower  Pliocene  of  the  Siwalik  Hills,  India, 
and  a  Tertiary  Lignite  near  Padang,  Sumatra. 

Family  19.     Muraenidae.     Eels. 

Body  much  elongated,  cylindrical  or  ribbon-shaped.  Premaxillae  fused  with 
ethmoid  and  vomer ;  upper  jaw  formed  laterally  by  the  toothed  maxilla.  Dorsal  fin 
much  extended,  often  meeting  the  anal  round  the  tail.  Pect  oral  arch  not  suspended  from 
the  cranium  ;  pelvic  fins  wanting,  Skin  naked,  or  with  small,  rudimentary,  cycloid 
scales.     Upper  Cretaceous  to  Recent. 

Urenchelys,  Sm.  Woodw.  With  separate  caudal  fin.  Upper  Cretaceous ; 
Sahel  Alma,  Lebanon,  and  English  Chalk. 

Eomyrus,  Storms.     Middle  Eocene  ;  Belgium. 

Species  of  existing  genera  from  marine  Upper  Eocene,  Monte  Bolca,  and 
freshwater  Upper  Miocene,  Oeningen. 


Order  2.     PHYSOCLYSTI.     GiU. 

Air  bladder,  when  present,  not  connected  by  a  tube  with  the  Oesophagus  in  the 
adult  (except  in  certain  Berycidae).  Gills  pectinate.  Pelvic  fins  usually  far  forwards  ; 
fin  rays  articulated  or  spinous.     Scales,  when  present,  cycloid  or  ctenoid. 


102 


PISCES 


CLASS  I 


Sub-Order  1.     ANACANTHINI.     Müller. 

All  fin  rays  flexible  and  articulated.    Pelvic  fins  jugular  or  thoracic.    Pharyngeal 
not  fused  together. 


Family  1.     Gadidae.      Cod-fishes. 

Elongated  fishea  with  hroad  head,  and  the  toothed  p^emaxilla  excluding  the 
maxilla  from  the  upper  margin  of  the  mouth.  Fehle  fins  jugidar.  Dorsal  fin 
extending  almost  the  whole  length  of  the  back,  sometimes  subdivided  into  two  or  three 
parts  ;  anal  fin  much  extended,  sometimes  divided  into  two.  Scales  small  and  smooth. 
Eocene  to  Eecent. 

Fossil  representatives  of  this  family  are  rare.  Nemopteryx  troscheli,  vom 
Rath,  occurs  in  the  Upper  Eocene  slates  of  Canton  Glarus.  Remains  of 
Phycis,  Strinsia,  Gadus,  and  Brosmius  have  been  described  from  the  Miocene  of 
Hungary,  Croatia,  and  Sicily.  Undetermined  skulls  are  known  from  the 
London  Clay  of  Sheppey. 


Family  2.     Pleuronectidae.     Flat-fishes. 

Disc-shaped  fishes,  much  laterally  compressed  and  asymmetrical,  with  both  the 
eyes  on  one  side  of  the  head — the  upper  side  when  at  rest.  Dorsal  and  anal  fins 
extending  almost  the  whole  length  of  the  trunk.  Pelvic  fins  jugular,  in  front  of  the 
pectorals.  Air  bladder  absent.  Scales,  when  present,  minute  and  ctenoid ;  upper 
side  of  body  colmired,  lower  side  colourless.     Upper  Eocene  to  Recent. 

The  flat-fishes  are  very  numerous  in  the  existing  fauna,  living  on  sandy 
coasts,  and  some  of  them  entering  the  mouths  of  rivers.     They  are  extremely 


,y/// 


Fig.  179. 
Solea  kirchbergana,  H.  v.  Meyer.     Lower  Miocene  ;  Unterkirchberg,  near  Ulm.     Nat.  size. 

rare  ämong  fossils.  A  small  species  of  Rhombus,  Klein,  occurs  in  the  Upper 
Eocene  of  Monte  Bolca.  Solea,  Cuv.,  is  known  from  the  Löwer  Miocene  of 
Würtemberg  (Fig.  179). 


Sub-Order  2.     PHARYNGOGNATHI.     Müller. 

Fin  7'ays  articulated  or  partly  spinous.     Lower  pharyngeal  bones  fused  together. 


SUB-CLASS  VI 


TELEOSTEI 


103 


Family  1.     Scombresocidae. 

Premaxüla  and  maxilla  forming  margin  of  upper  jaw.  Fectoral  fins  sornetimes 
much  enlarged,  wing-like  ;  pelvic  fins  abdominal ;  dorsal  fin  remote,  opposiie  the  anal 
fi,n  ;  all  fin  rays  articulated  and  flexible,     Scales  cycloid.     Eocene  to  Recent. 

Holosteus,  Ag.,  from  the  Upper  Eocene  of  Monte  Bolca,  and  extinct  species 
of  Belone,  Cuv.,  and  Scombresox,  Lac^p.,  from  the  Miocene  of  Europe,  are 
referred  to  this  family. 

Family  2.     Pomacentridae. 

Short,  laterally  compressed,  spinyfinned  fishes,  with  denoid  scales.  Dentition 
feeble.  Falatines  toothless.  Pelvic  fins  thoracic,  with  one  spine  andfive  divided  rays  ; 
dorsal  fin  exfended,  with  numerous  spines  ;  anal  fin  with  two  or  three  spines.  Eocene 
to  Recent. 

Here  are  placed  Odonteus,  Ag.,  from  the  Upper  Eocene  of  Monte  Bolca, 
and  Priscacara,  Cope,  from  the  Eocene  Green  River  Shales  of  Wyoming. 


Family  3.     Labridae.     Wrasses. 


Teeth  on 


Brilliantly  coloured  fishes  with  cycloid  scales  and  thick  fleshy 
margin   of  jaws  powerful ;    palate   toothless.       United   lower 
pharyngeals  much  thickened  and   forming  a  plate   beset  with 
rounded,  rarely  acuminate  grinding  teeth;  upper  pharyngeals 
usually  separate,  bearing  similar  teeth.     Eocene  to  Recent. 

The  wrasses  chiefly  inhabit  tropical  seas  at  the  present 
day. 

Phyllodus,  Ag.  (Fig.  180).  Known  only  by  pharyngeals 
bearing  smooth,  thin,  flattened  grinding  teeth.  Grinding 
surface  of  upper  plate  slightly  concave,  lower  convex. 
Teeth  arranged  in  rows,  the  middle  row  large.  Several 
layers  of  successional  teeth  usually  lie  beneath  those  in 
function.  Eocene  and  Miocene;  Europe  and  North 
America. 

Nummopalatus,  Rouault  (Pharyngodopilus,  Cocchi),  (Fig. 
181).     Lower  pharyngeals  triangulär,  covered  with  a  pavement  of  numerous, 

small,  round  or  oblong  grinding  teeth, 
of  which  there  are  always  several 
superimposed  layers.  Upper  pharyn- 
geals separate,  triangulär,  covered  with 
grinding  teeth.  Eocene ;  Virginia. 
Miocene  and  Pliocene ;  Europe. 
Taurinichthys,  Cocchi.  Miocene. 
pj^^  18^  The  existing  genera  Za&rws,  Artedi, 

Nummopalatus  muitidens,  Münst.  sp.   Miocene ;  Neu-  and  Scarus,  Forsk.,  are  also  representcd 

dörfl  a.  d.  March.     ^,  Lower  pharyngeal  with  dentition.     •       .-i       TTr»T-»pr  Tprtinrip«? 
5,  An  upper  pharyngeal.     Nat.  size.  m  tüe    Upper   iCruarieS. 


Fig.  180. 
Phyllodus  vudius,  Ag. 
Lower  pharyngeal  denti- 
tion,  nat.  size.  London 
Clay  ;  Sheppey  (after 
Cocchi). 


104 


PISCES 


CLASS  I 


Sub-Order  3.     ACANTHOPTERI.     Müller. 

Some  of  the  rays  of  the  pelvic  and  median  fins  spinous,  not  articulated.  Pelvic 
fins  usually  advanced  far  forwards.     Lower  pharyngeals  separate. 

In  the  existing  fauna  the  Acanthopteri  form  by  far  the  most  numerous 
group  of  fishes. 

Family  1.     Berycidae. 

Trunk  short,  compressed,  and  rather  deep,  with  denoid  or  cycloid  scales,  rarely 
naked.  Head  bones  ridged  to  form  large  mucous-cavities  ;  orhits  large  and  lateral  ; 
mouth  usually  oblique,  the  jaws  and  generally  also  the  palate  with  small  yointed  teeth. 
Operculum  more  or  less  serrated  or  ridged.  Pelvic  fins  thoracic,  with  an  anterior 
spine  and  more  than  five  divided  rays.     Upper  Cretaceous  to  Recent, 

The  living  Berycidae  are  marine  fishes,  most  of  them  inhabitating  consider- 
able  depths. 

Hoplopteryx,  Ag.  (Fig.  182).  Head  short.  Dorsal  fin  deep,  with  a  few 
spaced  spines  in  front ;  anal  fin  with  four  or  five  spines.     Scales  large  and 


1      ]b 

Hoplopterys  zippei,  A^assiz  sp.     Lower  Pläner  ;  Welilowitz,  Boheinia.     V:{  "at.  size  (after  Fritsch). 

ctenoid.  Common  in  the  Upper  Cretaceous.  H.  lewesiensis,  Mant.,  from  the 
English  Chalk,  and  other  species  originally  referred  to  the  surviving  genus 
Beryx. 

Sphenocephalus,  Ag.  Upper  Cretaceous,  Westphalia.  Pycnosterinx,  Heckel. 
Upper  Cretaceous,  Mount  Lebanon. 

The  two  surviving  genera,  Holocentrum  and  Myripristis,  Cuv.,  are  repre- 
sented  by  extinct  species  in  the  Upper  Eocene  of  Monte  Bolca. 


Family  2.      Percidae.      Perches. 

Trunk  elongated,  ivith  ctenoid  scales.     Premaxilla,  mandible,  vomer,  and  palatine 
with  pointed  teeth  ;  six  or  seven  branchiostegal  rays.     Pelvic  fins  thoracic  with  an 


SUB-CLASS  VI 


TELEOSTEI 


105 


anterior  spine  and  not  more  than  five  divided  ra/ys  ;  one  or  two  dorsal  ßns,  the  fore- 
most  pari  with  long  spines.     Eocene  to  Recent. 

The  perches  are  predaceous  fishes  of  the 
tropical  and  temperate  seas  and  fresh-waters. 
Numerous  fossil  representatives  occur  in  the 
Tertiary  formations  of  Europe  and  North 
America.  Some  belong  to  extinct  genera,  such 
as  Paraperea,  Sauvage,  Smerdis,  Ag.  (Fig.  183), 
Acanus,  Ag.,  Mioplosus,  Cope,  and  Erisma- 
topterus,  Cope.  Others  have  been  referred 
to  the  existing  genera  Serranus,  Pelates,  Dides,  Gerres,  Labrax,  and  Lates,  Cuv. 


Jb'iG.  183. 

Smerdis  minutus,  Ag.     Oligocene  ;  Aix, 
Provence.    Nat.  size. 


Family  3.     Sparidae.     Sea-breams. 

Brightly  coloured,  rather  deep-hodied  fishes,  with  very  delicately  serrated  denoid 
scales.  Margin  of  jaws  provided  in  front  with  conical  or  cutting  teeth  of  different 
shapeSj  which  are  usually  followed  hehind  hy  several  rows  of  round  or  oval  grinding 
teeth ;  palatine  and  vomer  toofhless.  Pelvic  fins  thoracic,  with  one  spine  and  five 
divided  rays :  dorsal  fin  single,  the  anterior  spinous  pari  almost  similar  to  the 
posterior  soft  part ;  anal  fin  with  three  spines.     Cretaceous  to  Recent. 

The  sea-breams,  which  are  easily  recognised  by  their  peculiar  dentition, 
live  at  the  present  day  in  the  tropical  seas,  feeding  especially  on  Mollusca 
and  Crustacea,  which  they  crush  with 
their  teeth. 

Sparnodus,  Ag.,  occurs  in  the  Upper 
Eocene  of  Monte  Bolca.  Sargus,  Cuv., 
Trigonodon,     Sismonda     (Fig.     184),    and 


J3.  H 


Fig.  184. 
Premaxillae  of  Sargus,  oiiter  (A)  and  inner 
(B)  Views.      Recent;    Mecliterranean.     Nat. 
size. 


Right  premaxilla  of  Chrysophrys  aurata, 
Linn.  Inner  aspect.  Recent ;  Mediter- 
ranean.     Nat.  size. 


Chrysophrys,  Cuv.  (Capitodus,  Münst.),  (Fig.  185),  ränge  from  the  Miocene  to 
existing  seas. 

Stephanodus,  Zittel.  .  Cutting  teeth  from  Upper  Cretaceous,  Libyan  Desert. 

The  families  Pristipomatidae,  Scorpaenidae,  Teuthididae,  Xiphiidae,  and 
Chaetodontidae  are  represented  in  the  Tertiaries  by  fishes  scarcely  differing 
from  the  surviving  forms. 


Family  9.     Palaeorhynchidae. 


Elongated,  low,  and  laterally  compressed  fishes. 
heak ;  jaws  toothless  or  with  very  small  denticles. 


Snout  produced  into  a  long 
Vertebrae  long  and  slender ; 


106 


PISOES 


CLASS I 


spinous  processes  and  ribs  delicate.  Pelvic  fins  thoracic,  with  several  rays ;  dorsal 
fin  extending  from  the  occiput  to  the  tau ;  anal  fin  extending  from  the  anus  to  the 
cleft  caudal  fin.     Eocene. 

The  two  sufficiently  well-known  genera  Palaeorhynchus,  Blv.,  and  Hemi- 
rhynchus,  Ag.,  occur  abundantly  in  the  Middle  Eocene  Calcaire  Grossier  of 


PcUaeorhynclms  ztftdi,  KTa,mh.  sp.     Upper  Eocene  ;  Kajcza,  Galicia.     1/3  nat- size. 

Paris,  the  Upper  Eocene  sandstone  of  Galicia,  in  the  black  slates  of  Glarus, 
and  near  Buchsweiler  in  Alsace.  F.  glarisianus,  Blv.,  H.  deshayesi,  Ag.,  and 
P.  zitteli,  Kramb.  sp.  (Fig.  186). 


Family  10.     Trichiuridae. 
Elongated   and   laterally   compressed,   almost    ribbon-shaped  predaceous  fishes. 


Fig.  187. 

Lepidopus  (AnencJielum)  glarisianus,  Ag.     Upper  Eocene  ;  Matt,  near  Glarus. 

.4,  Head.     JB,  Portion  oftrunk.    Nat.  size  (after  "Wettstein). 

Gape  of  mouth  wide,  jaws  and  palatine  bones  with  powerful  conical  feeth.     Dorsal 


SÜB-CLASS  VI 


TELEOSTEl 


107 


and  anal  fins  much  extended  witli  unarticulated  spines;  pelvic  fins  sometimes  rudi- 
nfientary  or  wanting.     Upper  Eocene  to  Recent. 

The  Trichiuridae  are  predaceous  fishes  of  the  tropical  and  sub-tropical 
seas,  living  both  near  the  coasts  and  also  in  deep  water.  Several  well-marked 
fossil  forms  occur  in  the  Eocene  and  Miocene. 

Extinct  species  of  the  existing  Lepidopus,  Gouan  (Anenchelum,  Blv.,  Lepido- 
pides,  Heckel),  are  found  in  the  black  slates  of  Glarus  (Fig.  187),  in  the 
Menilite  shales  of  the  Carpathians  (L.  carpathicus,  Kramb.),  and  in  the  Upper 
Miocene  of  Sicily  and  Tuscany. 

Trichiurichthys,  Hemithyrsites,  Sauvage.     Upper  Miocene  ;  Licata,  Sicily. 


Family  11.     Acronuridae. 

Trunk  deep  and  laterally  compressed,  covered  with  small  scales.  The  tau  in 
adult  examples  provided  with  one  or  several  hony  plates  or  spines.  Jaws  with  a  row 
of  cutting  teeth.     Anal  fin  with  three  spines.     Eocene  to  Recent. 

The  living  genera  dwell  chiefly  in  the  vicinity  of  coral  reefs. 

The  existing  genera  Acanthurus,  Forsk.,  and  Naseus,  Commerson,  are 
recorded  from  the  Upper 
Eocene  of  Monte  Bolca ;  the 
former  also  from  the  Calcaire 
Grossier  of  Paris  and  the 
Miocene  of  Vienna. 

Aulorhamphus,  Zigno 
(Calamostoma,  Steind.  non 
Ag.).     Eocene. 

Family  12.     Oarangidae. 

Horse-mackerels. 

Trunk  laterally  compressed, 
deep  or  elongated,  naked  or  with 
small  scales.  Teeth  conical. 
Spinous  portion  of  the  dorsal 
fin  shorter  than  the  soft  portion  ; 
pelvic  fins  thoracic,  sometimes 
rudimentary  or  absent.  Eocene 
to  Recent. 

Marine  predaceous  fishes 
of  the  tropical  and  temperate 
zones,  common'  in  Tertiary 
formations. 

Platax,  Cuv.  Fossil  in  the 
Upper  Eocene  of  Monte  Bolca 
and  in  the  dag  (Lower  Plio- 
cene)  of  Norfolk      Recent. 

Z  and  US,  Commers. 
Eocene  and  Recent.  j  -d  i  • 

Semiophorus,  Ag.  (Fig.  188).     Upper  Eocene;  Monte  Bolca  and  Belguim. 

Other  genera  with  extinct  representatives  are  the  following  -.—Amphistium, 


Fig.  188. 

Semioiihorxis  velifer,  Ag.    Upper  Eocene  ;  Monte  Bolca. 

1/2  nat.  size  (after  Agassiz). 


108  PISCES  CLASS I 

Ag.,   Vomer,  Cuv.,  Caranx,  Cuv.,   Carangopsis,  Ag.,  Lichia,  Cuv.,  Dudor,  Ag., 
Trachinotus,  Lac6p.,  Seriola,  Equula,  Cuv.,  Acanthonemus,  Ag.,  etc. 

Family  13.     Ooryphaenidae. 

IVunk  laterally  compressed.  Teeth  small  and  conical  or  wanting.  Dorsal  fin 
extendedj  mthouf  spines.     Eocene  to  Recent. 

Here  is  placed  the  genus  Mene,  Lac6p.  (Gasteronemus,  Ag.),  with  extinct 
species  in  the  Upper  Eocene  of  Monte  Bolca. 

Family  14.     Scorabridae.     Mackereis. 

Trunk  elongated,  naked  or  with  small  scales.  Teeth  conical.  Pelvic  fins  thoracic^ 
two  dorsal  fins,  the  hinder  usually  consisting  of  separate  tufts.     Eocene  to  Recent. 

Thynnus,  Cuv.  The  existing  tunny.  Mostly  large  cylindrical  fishes, 
covered  with  small  scales.  Anterior  dorsal  fin  with  twelve  to  fourteen  spines, 
which  are  not  remarkably  elongated ;  six  to  nine  small,  separate,  tufted  fins 
behind  the  posterior  dorsal  fin.  Teeth  small.  Several  species  in  the  Upper 
Eocene  of  Monte  Bolca,  the  Miocene  of  Oran,  Algeria,  and  the  Pliocene  Crags 
of  Belgium  and  England. 

The  genera  Falimphyes,  Ag. ;  Isurichthys,  Woodw. ;  Opisthomyzon,  Cope 
(allied  to  Echeneis,  Art.),  occur  in  the  black  slates  of  Glarus ;  Orcynus,  Cuv., 
in  the  Upper  Eocene  of  Monte  Bolca;  Megalolepis,  Kramb.,  in  the  Lower 
Menilite  shales  of  Baschka  in  Galicia.  The  existing  genera  Scomber,  Art., 
Aiixis,  Cuv.,  are  represented  in  the  Miocene  of  Croatia,  and  Gybium,  Cuv., 
in  the  Eocene,  Oligocene,  and  Miocene. 

The  families  Cyttidae,  Trachinidae,  Lophiidae,  Cataphracti,  Cottidae, 
Bleniidae,  and  Gobiidae  have  very  few  fossil  representatives  in  the  Tertiary. 

The  earliest  members  of  the  families  Mugilidae,  Sphyraenidae,  and 
Atherinidae  occur  in  the  Upper  Cretaceous  of  England,  Colorado,  and  New 
Mexico  (Calamopleurus,  Dixon ;  Syllaemus,  Apsopelix,  Pelycorapis,  Cope). 
Sphyraena,  Bloch,  Bhamphognathus,  Ag.,  Mesogaster,  Ag.,  and  Atherina,  Linn., 
occur  in  the  Upper  Eocene  of  Monte  Bolca ;  Mugil  princeps,  Ag.,  in  the  Upper 
Eocene  of  Aix-en-Provence. 

Family  25.     Aulostomidae.     Flute-mouths. 

Elongated  marine  fishes,  with  elongated  tube-shaped  snout  and  remote  dorsal  fin. 
Occiput  movably  articulated  with  the  vertebral  column ;   teeth  small.     Spines  little 

developed.  Pelvic  fins  abdominal  or 
^ thoracic.    Scales  small  or  absent.    Eocene 

^^^^^^^™^M^s^  *  At  the  present  day  the  Aulostomes 

Fig.  189.  chiefly    inhabit    tropical    seas.      Fistu- 

Amphisyle    heinrichsi,    Heckel.      Upper    Eocene ;    laria    Linn  ,  and  Aulostoma,  Lac6p.,  and 
Krakowiza,  Carpathians.     Nat.  size  (after  Heckel).  ,        '        .        '  .  .  i 

the  extmct  genera  Urosphen,  Ag.,  and 
Bhamphosus,  Ag.,  occur  in  the  Upper  Eocene  of  Monte  Bolca.  The  small, 
dorsally  armoured  genus  Amphisyle,  Klein,  which  still  survives,  characterises 


SUB-CLASS  VI 


TELEOSTEI 


109 


the  Upper  Eocene  Menilite  shales  of  Galicia  (Fig.  189),  and  the  Meletta  shales 
in  Upper  Alsace  and  the  Vienna  Basin. 


Family  26.     Blochiidae. 

Elongated  fishes  wiih  very  long  beak-shaped  snout,  which  is  formed  hy  the  equally 
produced  afid  finely  toothed  jaws.  The  entire  trunk  covered  with  cordiform  or 
rhomhic  hony  scales,  which  are  mostly  keeled  and  overlap  each  other.  Pelvic  fins 
small,  beneath  the  pedoral  pair ;   dorsal  fin  arising  at  the  occiput  and  extending 


Fig.  190. 
Blochiuslongirostris,\o\\&.     Upper  Eocene  ;  Monte  Bolca.     Ve  nat.  size  (after  Agassiz). 

almost  to  the  caudal  fin,  composed  of  a  spaced  series  of  long  spines ;  anal  fin  also 
much  extended  and  consisting  of  similar  spines  ;  caudal  fin  large,     Eocene. 

The  only  known  genus  is  Blochiiis,  Volta  (Fig.    190),  from  the  Upper 
Eocene  of  Monte  Bolca. 


Sub-Order  4.     LOPHOBRANCHII.     Cuvier. 

GUIs  arranged  in  tufts  on  the  branchial  arches  and  protected  by  an  operculum. 
Snout  with  tubulär  extension,  and  jaws  toothless.  Pelvic  fins,  often  also  the  anal 
and  caudal  fins  wanting.     Skin  armoured  with  thin  bony  plates. 

Only  very  few  fossil  representatives  of  the  two  families  of  this  remarkable 
group  are  known.  The  elongated  Solenostomidae,  in  which  all  the  fins  are 
developed,  have  an  Eocene  forerunner  in  the  genus  Solenorhynchus,  Heckel, 
from  Monte  Postale.     Extinct  species  of  Siphonostoma,  which  is  still  common 


Siphonostoma  albyi,  Sau  vage. 


Fig.  191. 
Upper  Miocene  ;  Licata,  Sicily  (after  Siiuvage). 


in  the  Mediterranean,  also  occur  in  the  Upper  Miocene  of  Licata,  Sicily 
(Fig.  191),  and  of  Tuscany.  Several  Tertiary  forms  of  Syngnathidae  are 
known ;  Syngnathus,  Pseudosyngnathus,  and  an  extinct  genus  Calamostoma,  Ag., 
occur  in  the  Eocene. 


Sub-Order  5.     PLECTOGNATHI.     Cuvier. 

Skin  covered  with  roughened  scales,  bony  spines  or  plates,  rarely  naked.  Skeleton 
incompletely  ossified.  Maxillae  and  premaxillae  fiised  together  into  a  solid  beak. 
GUIs  pectinate.  Pelvic  fins  wanting  or  represented  by  spines;  dorsal  fin  with 
articulated  rays  opposed  to  the  anal  fin. 


110  PISCES  CLAßsi 


Family  1.     Gymnodontidae.     Cuvier. 

Trunk  short  and  deep,  naked  or  covered  with  hony  spines.  Jaws  beak-shaped^ 
with  a  cutting  dental  plate  above  and  below,  either  undivided  or  in  right  and  left 
halves.     No  dorsal  spines.     Eocene  to  Recent. 

Fossil  remains  of  this  family  are  very  rare.     Large  jaws  of  Ofthagoriscas 
have  been  fouiid  in  the  Oligocene  of  Belgium.     Diodon  occurs  in  the  Eocene, 
^  j,  Oligocene,   and    Miocene ;    Gymnodus   in  the   Miocene  ; 

Heptadiodon  in  the  Upper  Eocene  of  Monte  Postale. 


Family  2.     Sclerodermidae.      Cuvier. 


^^Bj^r  Jaws  with  a  small  number  of  separate  teeth.     Skin  with 

p^^  jy.,  scales  or  roughened.    Dorsal  spines  usually  present.     Eocene 

PJiaiyiigeal  teeth.    A,  An-    tO  Recent. 
cistrodon  libycus,  Zitt.   Upper  ™,  ..  ^  .  j      -~>    t   ,         /  r,      . 

Chaik;  Gasr  Dachi,  Libyaii  ine   existing    genera    Ostracion  and    Batistes   {Froto- 

armSw«; Ge^'vafs^p.^'Eocene1  balisttm,  Massal.)  have  representatives  in  the  Upper 
Drme"r"'  ''^^'^  ^^'''''  ^''^''^^  Eocene  of  Monte  Bolca.  The  extinct  genera  Acantho- 
derma  and  Acanthopleurus,  Ag.,  occur  in  the  Upper  Eocene 
black  slates  of  Glarus.  The  teeth  described  as  Ancistrodon,  Eoemer  (Fig. 
192),  from  the  Upper  Cretaceous,  Eocene,  and  Oligocene,  may  belong,  at 
least  in  part,  to  the  pharyngeal  dentition  of  Scleroderms. 

Range  and  Distribution  of  Fossil  Fishes. 

Notwithstanding  the  apparently  favourable  circumstances  for  the  preserva- 
tion  of  fishes  due  to  their  aqueous  habitat,  their  geological  history  is  still  very 
imperfectly  known.  Complete  skeletons,  it  is  true,  are  rather  numerous  in 
clayey,  calcareous,  or  marly  shales,  which  were  laid  down  as  fine  mud  on  the 
bottom  of  former  lakes  and  near  the  shore  in  seas.  On  the  other  hand,  in 
rocks  of  coarser  grain  (sandstone),  in  very  many  shore  deposits,  and  also  in 
deep-sea  limestones,  there  are  usually  only  isolated  teeth,  scales,  dermal 
plates,  vertebrae,  scattered  bones  of  the  skeleton,  and  otolites,  which  are 
extremely  difficult  to  determine.  In  very  many  marine,  lacustrine,  and 
fluviatile  deposits,  fish  remains  are  almost  completely  wanting,  so  that  the 
formations  rieh  in  fossils  are  usually  separated  from  each  other  by  a  series  of 
strata  which  represent  long  periods  of  time. 

The  oldest  undoubted  traces  of  fishes  both  in  Europe  and  North  America 
occur  in  rocks  of  Silurian  age.  They  are  found  in  the  Ludlow  Bone-bed,  in 
the  light,  dolomitic,  fissile  limestone  of  the  island  of  Oesel  in  the  Baltic,  and 
in  Sandy  shales  in  Podolia  and  Galicia.  They  are  also  found  in  the  Onondaga 
Group  of  Pennsylvania.  The  determinable  forms  are  all  Selachii  and  primi- 
tive Östracodermi  (Coelolepidae,  Pteraspidae,  and  Cephalaspidae). 

In  the  Devonian  era  fishes  begin  to  attain  a  great  development,  and  are 
sometimes  discovered  in  a  remarkable  State  of  preservation,  especially  in  the 
Old  Red  Sandstone  of  Great  Britain,  the  Russian  Baltic  provinces,  Podolia, 
and  Galicia,  and  in  the  corresponding  formations  of  North  America.  Scattered 
fish  remains,  such  as  plates  of  Östracodermi  and  spines  of  Selachii,  also  occur 
in  the  uppermost  stages  (F,  G)  of  the  Silurian  basiri  of  Bohemia,  and  in  the 


( 


PHYLUM  VIII  VERTEBRATA  1 1 1 

Devonian  of  the  Eifel,  Nassau,  Westphalia,  and  Belgium.  Gigantic  Arthrodires 
(Dinichthys,  2'itanichthys,  Diplognathus)  and  Selachii  are  remarkably  abundant 
in  the  Middle  and  Upper  Devonian  ,of  Ohio,  Wisconsin,  and  New  York. 
The  Devonian  fish  fauna  consists  of  Arthrodires,  Ostracoderms,  many  Ganoids 
(Crossopterygii  and  Heterocerci),  Dipnoans  (Ctenodipterini),  and  Selachians 
(Pleuropterygii,  Acanthodii,  Holocephali). 

The  fishes  of  the  Carboniferous  System  are  obtained  partly  from  the 
marine  Carboniferous  Limestone,  partly  from  the  shales  and  sandstones  of  the 
productive  Goal  Measures.  The  enormous  development  of  the  Selachii,^  of 
which,  however,  only  teeth  and  fin  spines  are  commonly  preserved,  sharply 
distinguishes  the  Garboniferous  fish  fauna  from  that  of  the  Devonian  period. 
The  Gochliodontidae,  Psammodontidae,  and  Petalodontidae  are  almost  ex- 
clusively  confined  to  the  Garboniferous  Limestone,  while  the  Gestraciontidae 
are  also  well  represented ;  the  Acanthodians  and  Pleuropterygians  continue, 
the  Pleuracanthidae  begin.  The  heterocercal  Ganoids  are  the  principal 
associates  of  the  Selachii ;  the  Grossopterygii  and  Gtenodipterini  are  still 
present,  but  in  diminished  numbers. 

The  fishes  of  the  Permian  system  are  closely  similar  to  those  of  the  pro- 
ductive Goal  Measures.  They  occur  in  the  Rothliegenden  of  the  Saar  Basin, 
Bohemia,  Saxony,  Silesia,  and  France  ;  in  the  Magnesian  Limestone  of  England; 
in  the  Kupferschiefer  of  Thuringia  and  Hesse  ;  and  in  the  probably  contempor- 
aneous  strata  of  Texas  and  New  Mexico.  The  Heterocerci  are  by  far  the  most 
numerous.  Of  the  Grossopterygii,  Coelacanthus  and  Megalichthys  alone  survive  in 
Europe.  Among  the  Dipnoi,  the  genera  Ctenodus  and  Sagenodus  are  especially 
widely  distributed.  In  comparison  with  the  Garboni'ferous  fish  fauna,  that  of 
the  Permian  period  is  noticeably  destitute  of  Selachii.  Here,  however,  the 
remarkable  Pleuracanthidae  attain  their  maximum  development,  and  are 
associated  with  a  few  Gochliodontidae  {Menaspis),  Petalodontidae  (Janassa), 
and  Acanthodidae. 

The  abrupt  break  in  development,  which  is  observable  in  most  sections  of 
the  animal  and  plant  world  at  the  close  of  the  Palaeozoic  epoch,  is  also 
conspicuous  among  the  fishes,  although  the  Ti'iassic  fish  fauna  exhibits  many 
resemblances  to  that  of  the  Permian.  Among  Selachii,  the  Pleuracanthidae, 
Gochliodontidae,  and  Petalodontidae  are  wanting ;  the  Plagiostomi,  on  the 
other  band,  are  well  represented.  Teeth  and  fin  spines  of  the  Gestraciontidae, 
for  example,  are  very  numerous  in  the  Muschelkalk  and  uppermost  Keuper. 
The  occurrence  of  heterocercal  scaly  Ganoids  of  the  family  Palaeoniscidae,  as 
well  as  the  persistence  of  a  few  Grossopterygians,  is  indeed  reminiscent  of 
Palaeozoic  times ;  but  the  most  numerous  and  best  preserved  Triassic  fishes 
belong  to  the  enamel-scaled  Lepidostei,  of  which  the  Permian  system  aff'ords 
only  a  single  genus  (Acentrophorus).  Among  the  Dipnoi  the  persistent 
Ceratodus,  represented  principally  by  teeth,  plays  an  important  part.  The 
Teleostei  are  already  represented  by  some  small  Glupeoids  {Megalopterus). 

The  fish  fauna  of  the  Lias  is  a  direct  continuation  and  further  development 
of  that  of  the  Trias.  No  less  than  152  species  were  described  by  Agassiz  and 
Egerton,  and  of  these  79  occur  only  in  the  Lower  Lias  of  Lyme  Regis  in 
Dorset.  The  Middle  Lias  contains  few  fishes  ;  but  the  Posidonia  shales  and 
bituminous  limestone  of  the  Upper  Lias  e  in  Swabia  and  Franconia,  as  well  as 

1  Hay,  O.  F.,  The  Chiouological  Distribution  of  the  Elasniobraiichs  (Trans.  Amer.  Phil.  Soc. 
vol.  XX.),  1901. 


112  PISCES 


CLASS  I 


the  corresponding  strata  of  Werther,  near  Halle,  the  Departments  of  Calvados, 
Yonne,  and  Cöte-d'Or  in  France,  and  of  Ilminster  and  Whitby  in  England, 
again  yield  a  considerable  number  of  species.  The  Selachians  persist  in 
undiminished  numbers.  Undina  gulo,  Egerton,  from  Lyme  Regis  represents  the 
Coelacanthidae,  Chondrosteus  the  cartilaginous  ganoids.  The  majority  of  the 
Liassic  fishes,  however,  belong  to  the  scaly  Ganoids  of  the  order  Lepidostei, 
though  a  few  genera  of  the  heterocercal  Palaeoniscidae  still  survive.  A  new 
element  in  the  Liassic  fish  fauna  is  formed  by  the  thin-scaled  Amioids,  in 
which  the  vertebral  column  is  still  bent  upwards  to  the  upper  lobe  of  the  tail, 
and  remains  incompletely  ossified.  A  single  species  from  the  Lower  Lias  of 
England  (Mesodon  liassicus,  Eg.)  indicates  the  first  appearance  of  the 
Pycnodontidae.  Among  bony  fishes  a  few  small  Clupeoids  (Leptolepis)  may 
be  mentioned.  Ceratodus  and  Pholidophorus  are  present  in  the  Lower  Jura  of 
the  Western  United  States. 

In  the  Middle  Jura  shaly  deposits  with  well-preserved  fish  skeletons  are 
wanting.  Our  knowledge  of  the  fish  fauna  of  the  period  is  thus  confined 
to  detached  teeth,  fin  spines,  bones,  and  scales,  which  occur  occasionally. 
Almost  all  the  genera  observed  in  the  Dogger  occur  in  addition  in  the  Lias 
or  the  Upper  Jurassic.  Of  the  latter  the  most  numerous  discoveries  have 
been  made  in  the  fissile  limestones  of  the  neighbourhood  of  Solenhofen, 
Kelheim,  and  Eichstädt  in  Bavaria,  Nusplingen  in  Würtemberg,  and  Cerin  in 
the  Department  of  Ain,  France,  An  abundance  of  beautifully  preserved 
skeletons  of  Selachians,  Ganoids,  and  Teleosteans  have  been  obtained  from 
these  localities,  to  which  must  be  added  the  Portlandian  Limestone  of  Soleure, 
Neuchätel,  Hanover,  and  Boulogne-sur-Mer,  and  the  Purbeck  Beds  of  England 
as  formations  yielding  well-preserved  jaw- bones,  teeth,  spines,  scales,  and 
vertebrae.  The  heterocercal  Palaeoniscids  have  become  reduced  to  a  single 
genus  (Coccolepis).  Of  sharks  and  rays,  complete  or  partially  well-preserved 
skeletons  are  known,  which  indicate  close  relationships  or  absolute  identity 
with  various  still  surviving  genera.  The  Cestraciontidae  and  Lamnidae  are 
also  represented  by  several  extinct  genera,  and  the  Holocephali  are  much 
more  numerous  than  in  the  Lias.  Among  the  Ganoids  the  Coelacanthidae 
attain  their  maximum  development  in  varied  forms.  The  large  majority  of 
the  Upper  Jurassic  fishes  consist  of  Lepidostei  and  Amioidei,  with  Teleostei  of 
the  family  Leptolepidae. 

With  the  beginning  of  the  Cretaceous  system  there  is  an  important  change 
in  the  fish  fauna,  so  that  the  previously  dominant  Ganoids  become  more  and 
more  displaced  by  Teleosteans.  This  Substitution  is  almost  complete  in  the 
middle  and  upper  divisions  of  the  Chalk ;  in  the  Lower  Cretaceous,  on  the 
other  band,  there  are  still  a  few  types  of  Ganoids  surviving  from  Jurassic 
times.  The  fish  fauna  of  the  Cretaceous  system  thus  falls  into  two  well- 
marked  sections,  to  the  lower  of  which  belong  the  light-coloured  fissile  lime- 
stones of  Pietraroza,  the  limestones  of  Castellamare,  and  Torre  d'Orlando  near 
Naples,  of  Comen  (Istria),  Crespano  (Vicentin),  Lesina  (Dalmatia),  and  Grodischt 
in  the  Carpathians,  and  the  Neocomian  deposits  of  the  Yoirons,  near  Geneva. 
The  normal  deposits  of  the  Middle  and  Upper  Chalk  chiefly  contain  teeth, 
vertebrae,  and  isolated  fragments  of  Selachians,  Chimaeroids,  Pycnodonts,  and 
Physostomes ;  the  fissile  limestones  of  the  Lebanon,  the  marly  sandstone  of 
Westphalia,  and  the  Niobrara  Chalk  of  Kansas,  on  the  other  band,  yield  a  con- 
siderable number  of  well-preserved  skeletons.     Among  these  the  Ganoids  are 


PHYLUMviii  VERTEBRATA  113 

extremely  rare,  while  the  Physostomi  constitute  about  three-quarters  of  all 
the  known  species.  The  Physoclysti,  like  the  Physostomi,  are  represented 
chiefly  by  extinct  genera. 

With  the  beginning  of  the  Tertiary  period  there  is  a  still  closer  approxima- 
tion  to  the  condition  of  afFairs  at  present  prevailing. 

The  oldest  Eocene  fish  fauna  of  Europe,  from  the  London  Clay  of  southern 
England,  is  incompletely  investigated.  The  contemporaneous  deposits  in  the 
Paris  Basin  yield  only  a  few  fish  remains,  but  among  these  are  scales  of  the 
Ganoid  genus  Lepidosteus,  which  still  exists  in  North  America.  The  most 
important  and  best  known  deposit  of  Eocene  fishes  is  the  light-coloured  fissile 
limestone  of  Monte  Bolca,  near  Verona,  which  correspohds  in  age  approxi- 
mately  with  the  Calcaire  Grossier  of  the  Paris  Basin.  No  less  than  94  genera 
and  170  species,  including  several  sharks  and  rays,  have  been  described  from 
it.  Of  Ganoids  only  the  Pycnodonts  here  survive ;  all  the  other  fishes  belong 
to  the  Teleostei,  most  of  them  indeed  to  genera  which  at  present  live  in  the 
Indo-Pacific  and  Red  Sea,  in  the  tropical  Atlantic,  and  to  a  smaller  degree 
also  in  the  Mediterranean.  The  most  interesting  feature  in  this  fauna  is  the 
great  increase  of  the  Acanthopteri  and  the  decrease  of  the  Physostomi. 

A  remarkable  fish  horizon,  partly  marked  by  deep-sea  fishes,  occurs  at  the 
summit  of  the  Eocene,  represented  in  the  black  slates  of  Matt  in  Canton 
Glarus,  the  contemporary  Menilite  Shales  of  Styria,  Upper  Bavaria 
(Siegsdorf),  Upper  Alsace,  and  other  localities.  From  Glarus,  the  riebest 
locality  for  this  zone,  29  species  of  fishes  are  known,  according  to  Wettstein, 
and  all  of  these  belong  to  the  Teleostei.  In  a  remarkable  way  the  extinct 
genera  here  considerably  exceed  those  which  survive  to  the  present  day. 

In  the  western  states  of  North  America,  in  the  so-called  Puerco,  Wasatch, 
and  Bridger  formations  of  New  Mexico  and  Wyoming,  fossil  fishes  are  also 
abundant ;  but  these,  since  they  occur  in  freshwater  deposits,  have  little  in 
common  with  the  Eocene  forms  of  Europe,  which  are  met  with  alniost 
exclusively  in  marine  or  estuarine  deposits.  It  is  interesting  to  note  that  the 
existing  North  American  Ganoid  families,  Lepidosteidae  and  Amiidae,  are 
represented  here. 

The  Oligocene  and  Lower  Miocene  yield  but  scanty  fish  remains.  The 
occurrence  in  Europe  of  Amia  (Notaeus)  and  Lepidosteus  is  noteworthy. 

The  Middle  Miocene  Molasse  of  Switzerland,  Swabia  (Baltringen),  and 
Upper  Bavaria,  the  marine  deposits  of  the  Vienna  basin,  the  valley  of  the 
Rhine,  and  the  Aquitaine  basin  sometimes  contain  an  abundance  of  fish 
remains,  among  which  the  teeth,  dermal  plates,  and  spines  of  sharks,  rays,  and 
chimaeras,  the  vertebrae,  teeth,  and  scattered  bones  of  Teleostei  are  especially 
common.  With  few  exceptions  these  remains  are  referable  to  recent  genera. 
The  brackish-water  clay  of  Unterkirchberg,  near  Ulm,  the  freshwater  marl  of 
Oeningen  and  Steinheim,  the  Sarmatian  deposits  of  Radoboj  and  other  localities 
in  Croatia,  and  the  Cerithium  marl  of  the  Vienna  basin,  also  show  that  at  the 
time  of  their  formation  the  fish  fauna  of  the  fresh  and  brackish  waters  of 
Germany  was  not  very  diiferent  from  that  still  surviving  in  southern  Europe 
and  Asia  Minor. 

The  remarkably  rieh  Upper  Miocene  fauna  of  Licata  in  Sicily  exhibits  a 
mixture  of  marine  and  freshwater  fish  remains,  which  is  also  partially  notice- 
able  in  the  neighbourhood  of  Girgenti,  in  the  gypseous  marls  of  Sinigaglia, 
near  Gabbro  in  Tuscany,  Lorca  in  Spain,  and  Gran  in  Algeria.     In  his  mono- 

VOL.  II  l 


114  AMPHIBIA  CLASsii 

graph  of  1873,  Sau  vage  describes  52  species  from  Licata,  and  of  these  44  are 
of  marine  origin.  The  character  of  this  fish  fauna  is  essentially  Mediterranean, 
but  without  exceptio!!  the  species  are  extinct.  So  far  as  fishes  are  concerned, 
there  is  scarcely  any  noteworthy  difference  between  the  Pliocene  fauna  and 
that  of  the  present  day. 

The  distribution  of  fishes  in  time  aff"ords  many  facts  illustrating  the 
development  of  this  class.  In  the  Palaeozoic  epoch  there  were  only  Selachii, 
Holocephali,  Dipnoi,  Ostracodermi,  and  Ganoidei ;  the  Selachii  and  Ganoidei, 
indeed,  appearing  together  in  the  Silurian.  These  two  main  divisions  of  the 
phylurn  of  fishes  must  thus  have  become  separated  very  early,  if  indeed  they 
originated  from  a  common  stock. 

Fossils  beginning  in  the  Old  Red  Sandstone,  and  ranging  through  all 
later  formations,  prove  that  the  Holocephali  had  already  diverged  from  the 
Selachii  in  Palaeozoic  times,  and  the  branch  has  been  preserved  with  its 
partially  embryonic  characters  (polyspondyly,  autostyly)  until  the  present  day. 

The  origin  of  the  Dipnoi  is  quite  obscure.  Their  Palaeozoic  representa- 
tives  agree  in  many  respects  with  the  Crossopterygii.  As,  moreover,  the 
Dipnoi  also  share  important  characters  with  the  Holocephali,  it  seems  probable 
that  the  Holocephali,  Dipnoi,  and  Ganoidei  arose  from  a  common  stock. 

So  far  as  the  development  of  the  internal  skeleton  is  concerned,  the 
Ostracodermi  and  Arthrodira  are  quite  primitive.  Their  origin  is  wholly 
unknown.  Among  the  Ganoids  the  Crossopterygii  form  an  isolated  group, 
well  separated  from  the  other  Orders  both  phylogenetically  and  systematically, 
having  its  last  survivors  in  the  modern  Polypteridae,  and  probably  more  closely 
related  to  the  Dipnoi  and  Amphibia  than  to  the  other  Ganoids.  The  Hetero- 
cerci,  Lepidostei,  and  Amioidei  form  a  closely  connected  group  of  Ganoids. 
It  has  already  been  remarked  that  the  first  order  not  only  precedes  the 
Lepidostei  in  time,  but  is  also  probably  ancestral  to  them.  The  Amioids  may 
have  diverged  from  the  Lepidostei  during  the  Triassic  or  Jurassic  period. 

The  Teleosteans  are  merely  a  great  lateral  branch  of  the  Ganoids.  It  is, 
however,  improbable  that  they  are  of  monophyletic  origin ;  for  although  the 
Clupeoids  are  the  ancestral  group  of  most  of  the  Physostomi,  which  have 
arisen  from  the  Mesozoic  Amioids,  other  families  even  on  their  first  appearance 
seem  to  be  so  remotely  allied  to  Clupeoids  that  a  diff'erent  origin  must  be 
sought  for  them.  The  Physoclysti  are  indeed  only  derivations  of  the  Physo- 
stomi diflferentiated  in  various  directions. 

[The  section  Pisces  has  been  translated  and  revised  hj  Dr.  Arthur  Smith  Woodward,  of 
the  British  Museum,  who  has  attempted  to  bring  the  subject  up  to  date,  while  preserving  in 
the  main  the  author's  methods  and  principles  of  Classification. — Ed.] 

Class  2.      AMPHIBIA.      Amphibians  and  Batrachiaiis.i 

Cold-hlooded  vertebrates,  aquatic  or  terrestrial  in  hahif,  usually  naked,  hut  some- 
times  with  a  corneous  or  osseous  dermal  covering ;  respiration  both  branchial  and 
pulmonary  in  early  stages,  and  in  some  forms  gills  remain  fundional  throughout  life. 
Development  by  metamorphosis,  but  without  amnion  and  allantois.  Skull  with  two 
occipital  condyles.  llibs  never  attached  to  sternum.  Limbs  adapted  for  ambulation 
or  natation,  never  in  the  form  offins,  and  rarely  abseilt. 

^  Hoffmann,  C.  K.,  Die  Amphibien.  Bronn's  Classen  imd  Ordnungen  des  Thierreiclis,  vol.  VI. 
pt.  2,  187 S-7S.~  Wagner,  J.,  Natürliches  System  der  Amphibien,  1828-33. 


PHYLUMViii  VERTEBRATA  115 

In  external  appearaiice  amphibians  more  nearly  resemble  reptiles  than 
fishes.  The  body  is  generally  elongate,  and  terminates  as  a  rule  in  a  well- 
developed  tail,  although  some  small  forms  (Anura)  are  ecaudate.  Among 
recent  amphibians  limbs  are  wanting  only  in  the  Coecilians  {Gymnophiona). 
Certain  extinct  Stegocephalians  (Aistopoda)  appear  also  to  have  been  com- 
pletely  apodal ;  biit  elsewhere  two  pairs  of  limbs  are  invariably  present,  the 
anterior  usually  terminating  in  four  digits  and  the  posterior  in  five. 

Recent  amphibians  are  naked  with  the  exception  only  of  the  Coecilians, 
which  are  covered  with  small  scales  arranged  in  transverse  rings.  The  fossil 
Stegocephalians  usually  have  a  scaly  armature  on  the  ventral  surface,  and 
sometimes  on  the  dorsal  as  well. 

The  number  of  vertebrae  in  the  spinal  column  is  extremely  variable 
(10-150),  depending  upon  the  length  of  the  body  and  especially  the  tail. 
Cervical,  dorsal,  sacral,  and  caudal  regions  are  distinguished. 

The  most  primitive  form  of  vertebrae  occurs  in  the  Palaeozoic  Stego- 
cephalians, where  the  notochord  js  enclosed  by  thin  cylinders  of  bony  tissue, 
or  by  separate  pleurocentra  and  hypocentra,  as  in  early  Ganoids.  Where  the 
column  is  more  completely  ossified,  three  types  of  vertebrae  are  exhibited. 
The  first,  or  amphicoelous,  is  biconcave  ;  the  procoelous  has  the  anterior  vertebral 
face  concave  and  the  posterior  convex ;  and  in  the  opisthocoelous  type  the 
anterior  face  is  convex  and  the  posterior  concave. 

The  cervical  region  comprises  but  a  single  vertebra,  the  atlas,  although 
this  probably  corresponds  to  both  atlas  and  axis  of  higher  classes.  Its  con- 
cave anterior  face  receives  the  bony  or  cartilaginous  occipital  condyles,  and 
is  often  provided  with  a  spatulate,  forwardly  directed  basal  process.  Each  of 
the  dorsal  vertebrae  supports  a  neural  arch  (murapophysis),  which  becomes 
earlier  and  more  completely  ossified  than  the  centrum,  and  may  be  either 
suturally  united  or  anchylosed  with  the  latter.  The  two  halves  of  the  neural 
arch  unite  above  to  form  a  more  or  less  strongly  developed  spinous  process 
(spina  dorsalis) ;  and  they  bear  anteriorly  and  posteriorly  a  pair  of  oblique 
articular  processes  [processiis  ohliqui,  zygapophyses),  the  forward  pair  of  each 
vertebra  overridden  by  the  hinder  pair  of  the  next  in  front.  The  neural  arch 
also  Supports,  as  a  rule,  a  pair  of  transverse  processes  (diapophyses)  for  the 
attachment  of  ribs.  AVhen  the  latter  are  double-headed,  as  is  often  the  case, 
another  and  shorter  lateral  process  (parapophysis)  is  developed  by  the  body  of 
the  vertebra. 

The  sacral  region  is  also  formed  by  a  single  vertebra,  which  supports  the 
pelvis,  the  latter  being  attached  either  directly  by  means  of  exceptionally 
stout  transverse  processes,  or  by  sacral  ribs,  usually  of  peculiar  form.  Haemal 
arches  (haemapophyses,  "  chevron  bones  ")  are  commonly  borne  by  the  caudal 
series,  the  foremost  of  which  sometimes  have  ribs  attached  to  the  transverse 
processes  of  the  neural  arch.  The  entire  series  of  caudals  in  the  Annra  is 
fused  into  a  single  elongate  piece  called  the  coccyx. 

The  primordial  craiiium  remains  partly  cartilaginous  throughout  life,  and 
is  partly  replaced  by  bony  pieces,  which  are  eithev  direct  ossifications  of  the 
cartilaginous  capsule  (exoccipitals,  auditory  capsules,  quadrate,  sphen-ethmoid), 
or  are  investing  bones  (parietals,  frontals,  nasals,  vomer,  parasphenoid).  The 
basioccipital  and  supraoccipital  usually  remain  small  cartilaginous  tracts ;  but 
save  in  certain  Stegucephalia  and  a  fewother  forms,  the  exoccipitals  are  completely 
ossified,  and  bear  the  articular  condyles.     The  exoccipitals  are  of  considerable 


116  AMPHIBIA  CLASsii 

size,  and  enter  into  the  border  of  the  tympanic  region.  The  latter  is  roofed 
by  several  small  bones  corresponding  to  the  proötic  and  opisthotic  of  fishes,  or 
these  may  unite  into  a  single  element  called  the  petrosal.  The  antero-lateral 
walls  of  the  skull  remain  cartilaginous  ;  but  in  the  ethmoidal  region  an  ossifi- 
cation  takes  place,  forming  the  orbitosphenoid  which  is  usually  separate,  but 
sometimes  {Anura)  fuses  with  the  median  elements  to  form  a  single  ring- 
shaped  bone  (sphen-ethmoid). 

The  cranial  roof  is  formed  by  the  paired  parietals,  frontals,  pre-  and  post- 
frontals,  and  nasals;  and  in  Stegocephalians  there  are  present  in  addition  the  so- 
called  supratemporals,  squamosals,  postorbitals,  and  lachrymals.  The  palate  is 
formed  as  in  fishes  by  a  large  median  parasphenoid,  and  usually  paired  vomers, 
and  palatines.  There  is  no  movable  Suspensorium  for  the  lower  jaw ;  the 
cartilage  representing  it  unites  with  the  squamosal  above,  and  quadrato-jugal 
below.  Sometimes  an  ossified  quadrate  is  formed  at  the  end  of  the  suspen- 
sorial  cartilage.  Attached  to  the  quadrato-jugal  in  front  are  the  maxillae, 
and  anterior  to  these  the  premaxillae,  which  complete  the  rim  of  the  upper  jaw 
in  front.  Many  of  the  Urodeles  have  the  maxillae  and  quadrato-jugal  replaced 
by  connective  tissue.  Between  the  quadrate  and  parasphenoid  is  placed  the 
pterygoid,  usually  a  trifid  bone  which  joins  the  parasphenoid  by  its  shorter 
arm,  while  its  anterior  brauch  forms  the  outer  border  of  the  palatal  vacuity. 
The  palatines,  when  present,  usually  join  the  anterior  ends  of  the  pterygoids, 
and  extend  parallel  with  the  maxillae.  The  mandibular  ramus  is  composed 
of  three  or  four  elements,  as  in  fishes.  The  visceral  skeleton  is  formed  by 
the  paired  hyoid  bones,  and,  in  gill-breathers,  by  three  or  four  partially  ossi- 
fied branchial  arches. 

The  teeth  are  acutely  conical,  and  are  commonly  borne  by  the  mandible, 
maxillae,  premaxillae,  vomer,  and  palatines.  Earely  the  parasphenoid  and 
pterygoid  are  armed  with  minute  teeth,  and  only  certain  Anura  are  edentulous. 
Teeth  of  the  acrodont  type  have  their  bases  implanted  directly  upon  the 
rim  or  top  of  the  jaws ;  those  of  the  pleurodont  type  are  sunk  against  the 
inner  side  of  the  jaws.  As  in  Ganoids  and  bony  fishes,  worn  teeth  are  not 
replaced  by  successional  ones  developed  beneath  them,  but  new  ones  are 
formed  independently  alongside  the  old,  and  gradually  oust  the  latter  as  their 
basal  parts  become  reabsorbed.  Amphibian  teeth  difl'er  from  those  of  fishes 
chiefly  in  the  absence  of  vasodentine ;  and  the  spacious  pulp  cavity  which 
during  life  contains  vascular  or  connective  tissue,  occurs  in  the  fossil  State 
either  hollow  or  impregnated  with  mineral  matter.  Some  Stegocephalians 
have  complex  or  "  labyrinthodont "  teeth,  the  dentine  being  strongly  folded, 
as  in  certain  Crossopterygian  fishes. 

In  the  pedoral  arch  the  scapula  is  ossified  in  at  least  its  proximal  portion, 
where  it  joins  the  coracoid  and  pre-coracoid,  and  forms  the  articular  face 
for  the  humerus.  A  bony  sternum  is  usually  absent.  Stegocephalians 
are  peculiar  in  possessing  between  the  pectoral  limbs  one  median  and  two 
paired  exoskeletal  plates,  commonly  regarded  as  interclavicle  and  clavicles. 
The  fore-limb  is  composed  of  the  usual  bones,  humerus,  radius,  and  ulna ;  a 
carpus  which  is  either  cartilaginous  or  consists  of  two  rows  of  ossicles ;  and 
three,  four,  or  five  metacarpals  which  support  digits  with  from  one  to  four 
phalanges. 

The  pelvic  arch  is  composed  of  a  long  and  slender  bony  ilium,  which  is 
attached  either  directly  to  the  transverse  process  of  the  sacral  vertebra,  or  to 


ORDER  I  STEGOCEPHALIA  1 1 7 

the  sakral  ribs,  and  is  directed  obliquely  downward ;  a  flattened,  sometimes 
discoidal  bony  ischium ;  and  a  cartilaginous  or  ossified  pubis  lying  imme- 
diately  in  advance  of  the  ischium.  The  ilium  and  ischium  usually  take  part 
together  in  the  formation  of  the  acetabulum,  which  receives  the  femoral  head. 
In  the  Anura  the  tibia  and  fibula  are  fused.  The  tarsus  is  cartilaginous  or  com- 
posed  of  several  small  ossicles,  and  the  pes  resembles  the  manus,  except  that 
it  is  usually  pentadactyle. 

Four  Orders  of  Amphibians  are  recognised  as  follows  : — Stegocephalia,  Gymno- 
phiona,  Urodela,  and  Anura. 


Order  1.     STEGOCEPHALIA.^ 

Salamander  or  lizard-Uke  caudate  amphibians,  the  cranial  roof  and  whole  of  the 
cheek  covered  with  plates  ;  cranial  roof  posterior  to  the  orbitsformed  by  two  pairs  of 
median  and  two  pairs  of  lateral  elements  ;  pineal  foramen  always  occurring  in  the 
parietal.  Teeth  sharply  conical,  with  large  pulp  cavity,  and  walls  sometimes  highly 
complicated  by  infolding  of  the  dentine.  Vertebrae  consisting  either  of  simple 
cylinders,  or  of  separate  pleurocentra  and  hypocentra,  or  of  completely  ossified  amphi- 
coelous  centra.  Three  exoskeletal  plates  present  in  the  thoracic  region,  interpreted 
as  clavicles  and  interclavicle.  Usually  a  ventral  and  som,etimes  a  dorsal  armouring 
of  small  overlapping  scales. 

The  Stegocephalians  ränge  from  the  Carboniferous  to  Upper  Trias, 
and  comprise  the  largest  known  amphibians.  A  tail  is  invariably  present,  and 
in  most  cases,  two  pairs  of  limbs  ;  only  a  few  genera  are  apparently  destitute 
of  appendages. 

Unlike  recent  amphibians,  most  Stegocephalia  possess  a  well-develbped  dermal 
armour  of  bony  scales  or  scutes,  which  almost  always  Covers  the  ventral  sur- 
face  of  the  body,  and  sometimes  extends  to  the  under  side  of  the  limbs  and 
back  as  well.  Dorsal  scales,  however,  are  thinner  than  the  abdominal,  and 
are  usually  round  or  oval.  The  ventral  scutes  are  sometimes  thickened,  and 
always  arranged  in  regulär  series.  The  abdominal  series  form  oblique  rows 
meeting  at  a  sharp  angle  along  the  median  line,  but  those  covering  the 
thoracic,  pectoral,  and  caudal  regions,  and  under  side  of  the  limbs  are  arranged 
in  difFerent  patterns.     The  scales  are  of  true  bony  tissue,  and  vary  considerably 

^  Literature  : 

Amnion,  L.  v..  Die  permischen  Amphibien  der  Rheinpfalz.  Munich,  1889.  [Extensive  biblio- 
graphy.  ]— 5a?^r,  O.,  The  Stegocephali :  a  Phylogenese  Study  (Anat.  Anz.  vol.  XI.  No.  22),  1896.— 
Broüi,  F.,  and  Stickler,  L.,  lieber  Eryops  megacephalus  Cope  (Palaeontogr.  vol.  XLVI.),  1899.— 
ßm-meister,  II.,  Die  Labyrinthodonten  aus  dem  bunten  Sandstein  von  Bernburg.  Berlin,  1840.— 
Die  Labyrinthodonten  aus  dem  Saarbrücker  Steinkohlengebirge.  Berlin,  1850. — Cope,  E.  D., 
Synopsis  of  the  extinct  ßatrachia  and  Reptilia  of  North  America  (Trans.  Amer.  Phil.  Soc.  vol. 
XIV.),  im^.—Ibid.  N.S.,  vol.  XVI.,  1886.— Batrachia  of  the  Permian  Period  of  North  America 
(Amer.  Nat.  vol.  XVIII.),  \%d>i.—CredneT,  H.,  Die  Stegocephalen  aus  dein  Rothliegenden  bei 
Dresden.  Parts  I.-X.  (Zeitschr.  deutsch,  geol.  Ges.),  1881-93. — Fraas,  E.,  Die  Labyrinthodonten 
der  schwäbischen  Trias.  (Palaeontogr.  vol.  XXXVI.),  1889.— ^r/for/;,  .4.,  Die  Fauna  der  Gaskohle 
und  der  Kalksteine  der  Permforniation  Böhmens,  vols.  I.-IIL,  1883-94. — Hiixley,  G.  ^.,  Vertebrate 
Remains  from  Kilkenny  (Trans.  Roy.  Irish  Acad.  vol.  XXIV.),  1867. — Jaekd,  0.,  Die  Organisation 
von  Arehegosaurus  (Zeitschr.  deutsch,  geol.  Ges.  vol.  XLVIIL),  1896. — lieber  die  Körperform  und 
Haut  l»edeckung  von  Stegocephalen  (Setzber.  Ges.  naturf.  Freunde,  Berlin),  1896. — Meyer,  H.  v.,  Zur 
Fauna  der  Vorwelt,  pt.  2,  Frankfort,  1847. — Ueber  den  Arehegosaurus  (Palaeontogi-.  vols.  I.,  VI. 
XV.),  1851,  1857,  1866. — Idevi,  and  Plienenger,  T.,  Beiträge  zur  Palaeontologie  Württembergs. 
Stuttgart,  1844. — Miall,  L.  C,  Report  on  the  Structure  and  Classification  of  the  Labyrinthodonts 
(Rept.  Brit.  Assoc,  42nd  and  43rd  Meet.),  1874-75. 


118 


AMPHIBIA 


CLASS  II 


in  form,  the  more  common  varieties  being  oval,  rhomboid,  oblong,  fusiform,  or 
rod-shaped  (Pig.  193). 

The  vertebral  column  usually  remains  in  an  embryonic  condition,  and 
recalls  that  of  Ganoid  fishes.  The  degree  of  persistence  of  the  notochord  is 
very   variable,   but    only    the   most    specialised    gerj^ra    have    it    completely 


Fio.  194. 

Phyllos]ioiidylous  vertebrae  of  Branchinsmirus 
amUystomns,  Credner.  Eularged(afterCretlner).  eh, 
Notochord  ;  n,  Neural  arch  ;  sp,  spinous  process  ;  d, 
transverse  process  ;  z,  Zygapophysis. 


Fio.  193. 

A,  Ventral  armour  of  Branchiosaurus.  B,  Scutes  of 
Branchiosaurus  ;  C,  of  Hylonomus ;  D,  of  Pelosaurus  ; 
E,  of  Arckegosailms ;  F,  of  Sclerocephalns  ;  G,  of  Disco- 
saurKs  ;  H,  of  Fetrobates  (after  Credner). 


Fig.  195. 

Lepospondylons  vertebrae  of  Hylonomus.  ch,  Noto- 
cliord  replaced  by  niineral  matter  ;  k,  Bony  cylinder 
of  tlie  centruni ;  c,  Rib  (after  Credner). 


in  the  Branchiosauria  it   is  com- 


interrupted   by  ossification   of  the  centra 
pletely  persistent. 

Ossification  of  the  vertebral  column  is  least  complete  among  the  Fliyllo- 
spondyli    (Fig.    194),    where,    in    the    absence    of 
pleurocentra,  the  neural  arch  itself  extends  down- 
ward  and  joins  with  a  pair  of  delicate  hypocentra 
(or  intercentra)  to  enclose  the  notochord  and  to 
form  transverse  processes  for  support  of  the  ribs. 
In  the  Lepospo7idyli  (Fig.    195)  the  notochord  is 
persistent     and     encased     in     constricted     bony 
cylinders,    which   are   hourglass-shaped   in    longi- 
tudinal  section.     In   some  genera,   however,   the 
continuity   of   t.he   chord   is   all   but   interrupted 
by  ossification  of  the  middle  portion  of  the  centra. 
The  Temnospondyli  (Fig.    196)   have   the  ver- 
tebrae    composed     of     several     distinct     pieces. 
Rhachitomous  dorsal  vertebrae  of  Ossification   begins  with  the  neural   arch,  whose 
^/J,  zTgapophysTs;^7^TeLKrd^     halves  remain  separate  at  first,  but  later  coalesce 
tnun."^^'"''''"^'""'" ''  ^''''   ^^^"'""'=^"'   and  are  continued  above  into  a  stout  and  some- 

times  distally  thickened  spinous  process.  The 
centra  may  be  either  rhachitomous  or  embolomerous.  Those  of  the  rhachitomous 
type  are  formed  by  a  horseshoe-shaped   basal  piece  (hypocentrum  or  inter- 


Fio.  196. 


ORDER  I 


STEGOCEPHALIA 


119 


Rhachitomous    cauclal    vertebrae    of 
Archegosmirus.    Letteriiigas  in  Fig.  196. 


centrum,  the  tapering  extremities  of  which  are  directed  upward),  and  a  pair 

of  lateral  pieces,  or  pleurocentra ;  a  structure  which  is  paralleled  in  certain 

Ganoids  {cf.  Fig.  121).     The  hypocentrum  usually 

ossifies  in  advance  of  the  pleurocentra,  and  lies 

directly  underneath  the  neural  arch.    Occasionally 

a  small  horizontal  basal  piece  is  inserted  beneath 

the   pleurocentra   and    between   the   hypocentra. 

This  piece,  according  to  von  Meyer,  appears  to 

be  divided  in  the  anterior  caudals  of  Archegos'aurus 

(Fig.  197). 

The  rhachitomous   type  of  vertebrae   passes 

over   into   the   embolomerous   when    the   pleuro- 
centra  unite   with  the   hypocentrum   to  form  a 

complete    bony   ring,    which   coössifies   with  the 

neural   arch  above  (Fig.    198).      Or  occasionally 

the  crescentic  intercentrum  develops  into  a  com- 
plete ring,  and  the  pleurocentra  unite  with  each 

other  below  and  the  neural  arch  above  to  form  a  second  ring.  Some  genera 
(Cricotus)  have  rhachitomous  dorsal,  and  embolomerous 
caudal  vertebrae. 

The  most  advanced  stage  of  vertebral  ossification 
occurs  among  the  Labyrinthodonts,  where  the  centra  are 
solid  bony  discs,  slightly  amphicoelous ;  sometimes  they 
are  pierced  for  the  passage  of  the  notochord  (Fig.  199), 
or  a  Channel  is  visible  below  the  neural  canal  through 
which  it  extended  (Stereospondyli). 

There  is  usually  but  one  cervical  vertebra,  the  atlas, 
which   is   concave   in    front  and   facetted  to  receive   the 

exoccipital  condyles,  but  bears  neither  ribs  nor  anterior  zygapophyses.     Most 

or  all  of  the  presacral  or  dorsal  series  bear  ribs,  which 

may  be  either  single  or  double-headed.     The  single  sacral 

vertebra  is  provided  with  a  pair  of  stout  transverse  pro- 

cesses  for  the  attachment  of  sacral  ribs.     Haemal  arches 

(haemapophyses,  "  chevron  bones")  are  borne  by  the  caudal 

series,   being   joined   to   the   centrum  (pleurocentrum)  or 

intercentrum. 

The  craninm  (Fig.  200)  exhibits  the  depressed,  broadly 

triangulär  form  characteristic  of  amphibians,  but  is  invested 

by  bony  plates  which  form  a  very  different  pattern  from 

the    usual    amphibian    type,    while    resembling    in    some 

respects  those  of   Ganoids  and   Crocodiles.      The  cranial 

plates  are  usually  ornamented  externally  with  radiating 

sculpture,    pittings,    or   punctae,   and   sensory  canals   are 

often  conspicuous. 

The  cranial  roof  is  pierced  by  several  apertures,  the   tMomma  aiimani,  Huxiey. 

largest  of  which  are  the  orbits,  and  around  them  there  is 

often  a  sclerotic  ring.     The  anterior  nares  are  placed  close  to  the  border  of  the 

snout,  and  separated  from  each  other  by  a  considerable  interval'.     Another 

and    smaller   opening    occurs   at   the   median    suture    between   the   parietals, 

corresponding  in  position  to  the  so-called  parietal  foramen  of  Lizards. 


Fig.  19«. 

Embolomerous  vertebrae 
o{  Diplovertehroii.  punctatuvi, 
Fritsch.  Lower  Permian  ; 
Bohemia.  Vi  (after  Fritsch). 


Fio.  199. 
Dorsal  vertebrae  of 


120 


AMPHIBIA 


CLASS  II 


Pinx 


Fig.  20C. 


Premaxilla  ;  Mx,  Maxiila  ;  Na,  Nasal ;  Fr/,  Pret'rontal ;  Fr, 
Frontal ;  Ftf,  Postfrontal ;  Fa,  Parietal ;  For,  Postorbital ; 
X,  Anterior  ;  S7,  Posterior  squamosal ;  Ep,  Epiotic  ;  St,  So, 


The  thin,  flat  bones  constituting  the  cranial'  roof  are  of  dermal  origin,  as 
in  the  case  of  cartilaginous  Ganoids.     The  brain  cavity  is  protected  by  the 

large,  paired  parietals,  posterior  to 
which  are  two  pairs  of  supra- 
temporals,  the  outermost  being  the 
larger  and  forming  the  hinder 
border  of  the  auditory  notch.  The 
inner  or  median  pair  of  supra- 
temporals  are  commonly  described 
as  supraoccipitals  (so),  and  the  outer 
or  lateral  pair  as  "  epiotics "  (ep), 
although  clearly  of  dermal  origin. 
The  plate  anterior  to  the  epiotic  is 
usually  called  the  squamosal  (sq), 
and  in  front  of  this  lie  the  post- 
orbitals  (por)  and  large,  posterior 
cheek  plate  (st),  which  is  also  iden- 
tified  with  the  supratemporals.    The 

Dotäiil  Hiipect  o{  ihe  skull  of  ]\tnianerpetonpulcherrimum,     ,  -,       .  i  •  ,  i.l,„,       :j-1, 

Fritsch.     Kestore.1.     i/l  (after  Credner).     A,  Orbit ;  Fnix,     tWO    last-Uamed  pairS,   tOgether  Wlth 

the  so-called  epiotics,  are  wanting  in 
_  _  .     _  all   modern   amphibians.      Anterior 

Supratemporal ;  Ju,  Jugal.  ^-i  •    .    i  ji^i.  j.t_ 

to  the  parietals  and  between  the 
orbits  is  a  pair  of  usually  elongate  narrow  frontals,  and  anterior  to  these  a 
pair  of  large  nasals  with  openings  for  the  external  nares  at  their  an tero- lateral 
angles.  A  pair  of  curved  dentigerous  premaxillae  (pmx)  terminate  the  snout 
in  front. 

The  frontals  rarely  enter  into  the  border  of  the  orbits.  These  openings 
are  usually  bounded  behind  by  the  post- 
orbital and  postfrontal,  the  latter  plate 
being  invariably  present ;  mesially  by 
the  postfrontal  and  prefrontal ;  and 
exteriorly  by  a  long  cheek  plate  called 
the  jugal.  Yery  often  a  narrow  tri- 
angulär bone,  the  lachrymal,  is  inserted 
between  the  prefrontal  and  jugal,  but 
is  usually  pushed  forward  in  advance 
of  the  orbit.  The  postero- inferior 
cranial  angle  is  formed  by  the  quadrato- 
jugal,  which  sometimes  develops  a  pro- 
cess  on  the  under  side  for  articulation 
with  the  lower  jaw.  In  some  of  the 
larger  Stegocephalians  the  distal  end 
of  this  process  is  separated  off  from  the  *^'"  "'^^' 

j       /"     .          i    ,                   ^                    -,    j.  Palatal  aspect  of  the  skull  of  Branchiosaurus.     Re- 

quadratO-JUgal    by  a   SUture,  and   lOrmS  stored.     2/1  (after  Credner).     Pvix,    Premaxilla;   Mx, 

a   distinpt  nnadrafp  hnnp         Tnirnncr  thp  ^I^xilla ;  QaJ,  Quadrato-jugal ;  Ft,  Pterygoid  ;  FSph, 

a  aistinct  quaarate   DOne.       JOinillg  tne  presphenoid;  P^Palatine;  Fn,  Vomer. 

quadrato-jugal  in  front  is  the  maxillary, 

a   long,    narrow,  gently  curved   bone,  which  completes  the  outer   border  of 

the  cranium  as  far  as  the  premaxillae. 

Most  Palaeozoic  Stegocephalians  had  the  basiocciput  cartilaginous,  but  in 
the  Labyrinthodonts  and  certain  other  forms  the  supratemporals  are  followed 


et«/ 


ORDER  r 


STEGOCEPHALIA 


121 


by  a  pair   of  obliquely  inclined  bony  exoccipitals,  which  bear   the  articular 
condyles. 

The  under  side  of  the  cranium  is  remarkable  for  the  ilarge  size  of  the 
palatal  vacuities,  and  great  development  of  the  parasphenoid,  which  expands 
posteriorly  into  a  broad,  thin  plate.  It  extends  forwardly  as  a  long,  slender 
process,  and  unites  with  the  relatively  large-sized  vomer,  the  latter  element 
being  paired  in  the  earlier,  unpaired  in  the  later  forms.  The  vomer  usually 
joins  the  premaxillae  anteriorly,  and  is  bounded  exteriorly  by  the  maxillae, 
the  internal  nares,  and  front  portion  of  the  palatines.  Its  broad,  fiat  surface 
is  either  edentulous  or  set  with  minute  teeth,  but  occasionally  one  or  two 
powerful  tusks  are  present  in  front  of  the  narial  openings,  and  there  is  a  series 
of  smaller  teeth  bordering  the  anterior  and  lateral  edges  of  the  vomer. 

The  posterior  expansion  of  the  parasphenoid  unites  with  a  trifid  bone,  the 
pterygoid.  The  short  inner  arm  of  the  latter  in  fact  often  envelops  the 
parasphenoid ;  its  long,  forwardly  directed  process  extends  parallel  with  the 
palatine  and  maxilla,  forming  the  outer  border  of  the  palatal  vacuity;  and  its 
short  posterior  brauch  unites  with  the  quadrato-jugal  and  limits  the  temporal 
vacuity.  The  palatines  lie  between  the  vomer  and  anterior  extremities  of  the 
pterygoid.  They  are  bordered  externally  by  the .  maxillae,  as  a  rule,  and 
anteriorly  .by  narial  openings.     They  frequently  bear  a  series  of  small  teeth. 

The  lower  jaw  (Fig.  227)  of  all  Stegocephalians  extends  the  füll  length  of 
the  skull,  and  in  consequence  the  gape  of  the  mouth  is  very  wide,  as  in  Anura. 
The  mandibular  ramus  is  composed  of  three  pieces,  of  which  the  dentary  forms 
the  tooth-bearing  anterior  portion,  and  the  angular  the  lower  portion  ;  behind 
the  dentary  and  above  the  angular  is  the  articular,  which  bears  a  deep  trans- 
verse  articular  facette  terminated  behind  by  an  elevated  process.  Superimposed 
on  these  three  pieces  on  the  inner  side  of  the  jaw  is  a  membrane  bone  called 
the  splenial  (or  opercular).  Teeth  occur  in  regulär  series,  decreasing  in  size 
posteriorly ;  and  sometimes  one  or  two  greatly  enlarged  teeth  occur  at  the 
Symphysis.     The  union  of  the  two  rami  in  front  was  ^ 

probably  ligamentous  in  most  cases. 

The  teeth  ^  of  the  smaller  Palaeozoic  Stegocephalians 
are  smooth,  slender,  hollow,  and  conical  (Fig.  202),  and 
implanted  either  directly  in  the  supporting  bone,  or 

attached    by    a    cement-base. 

Very  often  the  lower  half  or 

two-thirds  of  the  crown  is  ex- 
ternally grooved  or  striated,  in 

which   case  a  radial   infolding 

of    the    dentine    extends    for 

an    equal    height    (Fig.    203).   with  simple,  smooth  t«^eth.   a, 

^y         ^  n  i       A     ^    1.    1         Vi-   £,  Enlarged  (afterCrpfiner). 

Numerous  nne  dentnie  tubules    '^     >        =    ^ 
extend  downward  toward  the  periphery,  and  tangen- 
Lower  half  with  a  portion  broken   tiallv  to  the  walls  of  the  radial  prolouffations  of  the 

away  to  show  the  folded  dentine.  ,    -^  .  _        ^  -i  •      ,      i    ,       .  i  i 

pulp  cavity.  In  the  more  complicated  teeth,  secondary 
and  even  tertiary  branching  of  dentine  tubules  may  occur,  and  at  the  same 
time  undulating  or  tortuously  folded  layers  of  cement,  such  as  covers  the 
exterior  of  the  tooth,  may  become  intercalated  between  the  bundles  of  dentine 

'  ^  Credner,  H.,  Zur  Histologie  der  Faltenzähne  palaeozoischer  Stegocephalen  (Abhandl.  sachs.  Ges. 
Wiss.  vol.  XX.),  1893. 


Fig.  202. 
Lower  jaw  of  Brani'hiosaiinis 


Fig.  203. 
Tooth    of   Archegosaurus,   en 
larged.     A,   Outer  surface, 


122 


AMPHIBIA 


CLASS  II 


tubules.       This    gives    rise    to   the    highly    characteristic    "  labyrinthodont " 

structure,    which   reaches    its    extreme    development   among    the    larger   and 

_f  geologically     later     Stego- 

cephalians  (Fig.  204).  The 
internal  structure  becomes 
progressively  less  compli- 
cated  toward  the  apex  of 
the  tooth,  above  the  zone 
where  radial  infoldings  of 
the  walls  leave  off,  the 
dentine  is  traversed  simply 
by  straight  tubules  radiat- 
ing  from  the  pulp  cavity. 
The  insertion  of  the  teeth 
may  be  of  the  acrodont  or 
pleurodont  type,  as  already 
described,  or  they  may  be 
seated  in  shallow  alveoli. 

Traces  of  branchial 
arches  being  conspicuous 
in  the  young  of  several 
Palaeozoic  genera,  the  sup- 
position  is  natural  that 
respiration  was  by  gills 
during  the  early  stages  of 
all  Stegocephalians. 
The   Stegocephalian  pedoral   arch   (Fig.   205)   is   of    unique   construction, 

differing   from   that   of    other   amphibians    in    notable   respects.       The   most 

characteristic,    as    well 

as     the     largest     and 

usually  best  preserved 

bones,    occupy    an    ex- 

ternal  position  on  the 

thorax     between     the 

pectoral  limbs.     These 

bones     are     three     in 

number,  and  as  a  rule 

prominently    sculp- 

tured.       The     median 

dement    identified    as 

tue       interclavicle       (or         ^^  Pectoral  arch  of  Branchiosaums.     B,  Melanerpeton  (after  Credner). 
ATif  rkof  c»vrmTn\  irtiT'ioc    ^<"^  Interclavicle;   ci,  Clavicle ;   co,  Coracoid  ;   sc,  Scapula  [  =  cleitlirum  of 

entosteinum)  varies   cegenbaur]. 

considerably    in    form 

and    size   amongst    different    genera.       Most    frequently   it    is    rhombic,    but 

sometimes   transversely  oval,  and   may    terminate  behind   in  a   long  median 

extension. 

Partly  overlapping  the  forward  portion  of  the  interclavicle  are  the  paired 
plates  which  correspond  to  the  clavicles  of  other  amphibians.  Their  posterior 
ends  are  slender  and  slightly  curved  upwards ;  the  anterior  end  is  expanded 
into  a  triangulär  or  oval  plate,  often  sculptured,  but  sometimes  smooth  as  if  it 


Cross-section  of  a  tooth  of  MaModonsau  ms  jaegeri.    '^/i  (after  Owen). 
P,  Pulp  cavity  ;  c,  Dentine  tubules. 


Fig.  205. 


STEGOCEPHALIA 


123 


had  been  embedded  in  the  integument.  A  fiat,  semicircular,  or  lunate  plate, 
interpreted  as  the  coracoid,  is  placed  at  a  slight  distance  behind  the  clavicles, 
and  there  is  also  a  narrow  or  rod-like  piece  with  expanded  distal  extremities, 
corresponding  to  the  scapula  of  other  groups.  [Gegenbaur,  and  following  bim 
G.  Baur,  interpret  these  bones  differently,  holding  that  the  coracoid  was  in  all 
probability  cartilaginous,  and  identifying  the  bone  commonly  known  by  thatr 
name  as  the  scapula,  and  the  so-called  scapula  as  the  deithrum.  The  latter,  as 
shovvn  by  Gegenbaur,  was  attached  to  the  distal  end  of  the  clavicle.] 

The  bones  of  the  appendicular  skeleton,  so  far  as  known,  agree  in  form, 
number,  and  arrangement  with  those  of  living  Urodeles.  The  humerus  is 
rarely  furnished  with  articular  condyles,  its  extremities  remaining  as  a  rule 
cartilaginous.  Ulna  and  radius  are  always  separate,  simple,  more  or  less 
elongate,  and  without  articular  faces.  The  carpus  is  imperfectly  known ;  in 
many  Palaeozoic  genera  it  appears  to  have  been  cartilaginous,  in  others  partly 
ossified.      The  metacarpals  and  phalanges  are  slender  and  elongate. 

The  pelvic  arch  (Fig.  206)  is  strongly  developed,  but  seldom  so  well  pre- 
served  that  the  form  and  position  of  all  the  parts  are  clearly  distinguishable. 
The    ilium    is   short, 

stout,  somewhat  ex-  /^xVi  ^^ 

panded     at     the  '*^"'' 

extremities,  and 
attached  to  the  sacral 
ribs.  Ischium  and 
pubis  sometimes 
unite  to  form  a  single 
large  plate  (ischio- 
pubis),  or  they  may 
remain  separate.  The 
inner  edges  of  the 
ischia  form  a  Sym- 
physis in  the  median 
line.  The  pubes, 
which  are  smaller, 
sometimes  remain  car- 
tilaginous amongst 
Palaeozoic  forms. 

The  hind-limh  is 
almost  always  more 
strongly  developed  than  the  fore-limb.  The  femur  is  a  strong,  elongate  bone, 
witljout  an  ossified  capitulum,  but  often  with  well-formed  distal  condyles. 
Tibia  and  fibula  remain  separate,  and  resemble  the  corresponding  bones  of 
the  anterior  limb.  The  tarsus  is  either  cartilaginous  or  composed  of  two 
rows  of  small  bones.  The  pes  is  provided  with  five  digits,  but  is  otherwise 
closely  similar  to  the  manus  ;  sometimes  the  second  digit  is  the  longest,  in 
other  cases  the  third. 

Hahitat. — The  mode  of  occurrence  of  Stegocephalians  in  the  Goal  Measures, 
Lower  Permian,  and  Keuper,  indicates  that  they  were  either  freshwater 
inhabitants,  or  terrestrial  forms.  Some  of  the  smaller  genera  appear  to  have 
sequestered  themselves  in  hollow  tree-stumps,  since  in  Nova  Scotia,  at  least, 
their    remains   are   commonly   found    in    cavities   of    decayed    Sigillaria    and 


Pelvic  arch  of  Mastodonsannis  giganteus,  Jaeg.  (after  Fraas). 
1,  Iliuin  ;  Isch,  Ischiuin  ;  Pu,  Piibis  ;  Ac,  Acetabulum. 


124 


AMPHIBIA 


CLASS  II 


Lepidodendroii  trunks.  The  larger  forms,  some  of  which  attained  gigantic 
size,  were  predatory,  and  probably  subsisted  on  other  amphibians,  fishes,  and 
crustaceans. 

Sub-Order  A.     PHYLLOSPONDYLI.     Credner.     {Brandiiosaiiria.) 

Notochord  persistent  and  encased  in  imperfect  barrel-shaped  vertebrae  formed  hy 
a  pair  of  delicate  hypocentra  and  downward  prolongations  of  the  neural  arch, 
tut  without  pleurocentra.      Teeth  simple,  hollow. 


Family  1.     Branchiosauridae.     Fritsch. 


Lizard-like  Stegocephalia  with  broad,  obtusely  roimded  heads.  Basiocciput 
cartilaginous,  and  also  the  carpus,  tarsus,  and  pubis.  Ribs  short  and  straight,  with 
simple,  thickened  proximal  ends.  Pubis  not  ossified.  Ventral  scales  thin,  small, 
pointed,  and  arranged  in  regulär  series.     Carboniferous  and  Permian. 

BranchiosauruSy  Fritsch  {Protriton,  Pleuroneura,  Gaudry),  (Figs.  201,  202, 
205,    207,    208).     Body    15-20   mm.    long.     Head   about   as   broad   as   long, 

truncate  behind,  with  shallow 
auditory  notch,  and  very  large 
elliptical  orbits.  Sclerotic  ring 
of  about  30  small  plates,  and  also 
a  supplementary  series  of  smaller 


Fig.  207. 

Branchiosaiirus  amhlystomus,  Credner.  Rothl legendes, 
Niederhässlicli,  near  Dresden.  A,  Skeleton  of  adult  indi- 
vidual,  1/].  B,  Restoration  of  a  larval  form  with  gill  arches 
(after  Credner). 


ßranchiosaunis  petrolei,  Gaudry  sp. 
Lower  Permian ;  Autun.  i/i  (aft<;r 
Gaudry). 


plates  irregularly  arranged.  Cranial  plates  radially  striated  or  punctate. 
Parasphenoid  greatly  expanded  behind,  and  uniting  with  trifid  pterygoid. 
Vomer  paired,  the  two  pieces  triangulär  ;  palatines  imperfectly  known.  Jaws 
with  a  Single  series  each  of  slender,  closely  spaced  conical  teeth.  Inter- 
clavicle  sub-rectangular,  externally  furrowed.  Ilium  stout,  hourglass-shaped ; 
ischium  delicate,  triangulär. 

The  entire  ventral  siirface  of  the  body,  together  with  a  portion  of  the  tail  and 
limbs,  was  protected   by  deeply  overlapping   cycloidal  scales  (Fig.   193)  arranged  in 


ORDER  I  STEGOCEPHALIA  125 

several  distinct  series.  Those  of  the  thoracic  region  form  transverse  rows ;  those  of 
the  pectoral  region  oblique  rows  converging  posteriorly  toward  the  median  line ; 
those  of  the  abdominal  region  oblique  rows,  converging  at  a  lesser  angle  in  the  opposite 
direction ;  and  those  of  the  under  side  of  the  tail  and  legs  form  slightly  curved  trans- 
verse rows.  Functional  gill  arches  are  indicated  in  many  immature  examples  by  the 
regulär  series  of  minute  denticles  which  were  originally  arranged  on  them.  Tail 
known  to  have  been  about  as  long  as  trunk  wdth  the  head,  but  most  of  the  caudals 
unossified. 

This  genus  and  Archegosaurus  furnish  the  commonest  and  best  known  examples 
of  Palaeozoic  Amphibians.  Eemains  of  Branchiosaurus  are  abundant  in  the  fine- 
grained  limestone  of  the  middle  Eothliegendes,  near  Dresden,  where  the  small  bones 
are  clearly  outlined  in  wählte  against  a  grayish-coloured  matrix.  Credner's  elaborate 
researches  on  the  strueture  and  development  of  this  form  w^ere  based  on  comparisons 
of  over  1000  specimens.  Several  species  occur  also  in  the  Lower  Permian  of  Nürschan 
(Nyran)  and  Kunova  in  Bohemia,  and  Oberhof  and  Friedrichsroda  in  Thuringia. 

Pelosaurus,  Credner  (Fig.  193,  d).  18  to  20  cm.  long.  Skull  relatively  very 
large,  with  lachrymal  in  front  of  orbits,  and  no  supplementary  sclerotic  plates. 
Lower  Permian ;  Niederhässlich,  near  Dresden.     F.  laticeps,  Credner. 

Melanerpeton,  Fritsch  (Figs.  200,  205,  h).  2*5  to  13  cm.  long.  Skull  as  in 
Branchiosaurus,  but  more  produced  posteriorly,  and  squamosal  divided  (5^  and 
x).  Interclavicle  extended  into  a  long  posterior  process.  A  distinct  dermal 
armouring  not  present,  but  quantities  of  small  calcareous  shagreen-like 
particles  sometimes  observed  instead.  Branchial  arches  present  in  young 
examples.  Lower  Permian  of  Braunau,  Bohemia ;  Lhotka,  Moravia ;  and 
Niederhässlich,  Saxony. 

Dawsonia,  Fritsch.  Jaw- bones,  vomer,  palatines,  and  parasphenoid 
armed  with  teeth.     Lower  Permian  ;  Bohemia. 

Amphibamus,  Cope  ;  Pelion,  Wyman.      Goal  Measures  ;  Linton,  Ohio. 

Sub-Order  B.     LEPOSPONDYLI.     Zittel.     {Microsauria. ) 

Notochord  persistent  and  enclosed  in  constricted  hony  cylinders^  hourglass-shaped 
in  longitudinal  section.     Teeth  simple,  conical,  hollow. 

Family  1.     Microsauridae.     Dawson. 

Salamander  or  lizard-like,  usually  longicaudate  Stegocephalia.  Fore-limbs  less 
robust  than  the  hinder  pair,  carpus  and  tarsus  ossified  or  cartilaginous.  Eibs  long 
and  slender,  curved,  generally  double -headed.  Pubis  ossified. 
Ventral,  and  in  rare  cases  also  the  dorsal  surface  covered  with 
small,  round,  oblong,  oval  or  oat-shaped  scales.  Carboniferous 
and  Permian. 

^  Hyloplesion,  Fritsch.  Cranial  bones  smooth,  finely  striated 
or  punctate.  Orbits  large,  with  sclerotic  ring.  Tarsus  ossified. 
According  to  Fritsch,  both  dorsal  and  ventral  armatures  were 
present,  composed  of  overlapping  oval  scales  with  thickened 
posterior  border.     Lower  Permian:    Nürschan,  Bohemia,  and      ^  vertebra,  and 

tj^  T   1      c<  B,R\hofHylononuts 

Niederhässlich,  Saxony.  lyeiH,  Dawson.  coai 

Hylonomus,   Dawson   (Fig.   209).      Small    and    imperfectly   ^"scot'ia"!'^^'"'' 
known,  perhaps  identical  with  the  preceding.     Coal  Measures ; 
Nova    Scotia.       Other    allied    American    genera    are    Amhlyodon,    Dawson ; 


126 


AMPHIBIA 


CLAS8  II 


Hi/lerpeton,    Owen;    and     Brachydectes,    Cope,    all    small    and    fragmentarily 
preserved. 

Seeleija,  Fritsch.  Larval,  lizard-like  forms  under  2 "5  cm.  in  length,  with 
rounded  snout.  Teeth  smooth,  simple,  hollow,  present  on  all  bones  of  the 
palate,    those   of    the   premaxillae    much    larger    than    the    maxillary    teeth. 

Parasphenoid  a  long  slender  bone  ex- 
panding  behind  into  a  rectangular  plate. 
Gill  arches,  and  both  dorsal  and  ventral 
armour  present.  Scales  elongated  oval, 
ornamented  with  undulating  or  dichotomis- 
ing  lines.  Very  rare  in  Lower  Permian 
of  Nürschan,  Bohemia.  S.  pusilla,  Fritsch. 
Eicnodon,  Orthocosta,  Microbrachis,  Limner- 
peton,  Fritsch.  Lower  Permian  ;  Nürschan, 
Bohemia. 

Tuditanus,  Cocytinus,  Colosteus,  Lepto- 
phractus,  Pleuroptyx,  Cope.  Goal  Measures  ; 
Linton,  Ohio. 

Lepterpeton,  Huxley  (Fig.  2 1 0).  Lizard- 
like,  longicaudate,  with  narrow,  elongated 
head  and  tapering  snout.  Orbits  midway 
the  length  of  the  skull ;  carpus  and  tarsus 
cartilaginous.  Hind-limb  slightly  stouter 
than  the  anterior.  Ventral  scales  elongated 
rhombic.  Goal  Measures  ;  Kilkenny, 
Ireland. 

Keraterpetoii,  Huxley  {Ceraterpetuui, 
Huxley).  Salamander  -  like,  with  much 
elongated  tail ;  total  length  upwards  of 
50  cm.  Skull  broad,  rounded  anterior ly, 
Orbits  far  forward,  and  external  bones 
sculptured.  A  pair  of  large,  backwardly 
directed  horns  firmly  attached  to  the 
postero-lateral  cranial  angles.  Very  small 
ventral  scutes,  and  no  dorsal  armour. 
Goal  Measures ;  Kilkenny,  Ireland,  and 
Linton,  Ohio. 

Säncosmirus,  Fritsch  (Fig.  211).  Skull 
smaller  in  proportion  to  the  body  than  in 
Keraterpeton,  with  more  numerous  pre- 
sacral  vertebrae,  and  distinct  ossifications  in  carpus  and  tarsus.  Lower 
Permian  ;  Bohemia.     S.  crassus,  Fritsch. 

Urocordylus,  Huxley  and  Wright  (Oestocephalus,  Ptyonius,  Gope),  (Fig.  2L2). 
Body  and  tail  elongate,  total  length  about  50  cm.  Fore-limb  slightly  less 
developed  than  the  bind,  both  pentadactyle.  Skull  depressed,  triangulär, 
posteriorly  truncate.  Orbits  forwardly  situated.  Tail  nearly  twice  as  long 
as  the  trunk  with  the  head.  Gaudal  vertebrae  about  80  in  number,  with 
long  neural  and  haemal  spines,  expanded  and  crenulated  distally.  Ventral 
armour  composed  of  upwards  of  100  rows  of  scutes  converging  toward  the 
median  line,  in  form  elongated  oval,  fusiform  or  oat-shaped.     Goal  Measures ; 


Fk!.  210. 

Ijepterpeton  dobbsii,  Huxley.     Carboniferou.»: 
Kilkenny,  Ireland.     »/^  (after  Huxley). 


ORDER  I 


STEGOCEPHALIA  127 

Lower    Permian ;    Nürschan,    Bohemia.        U.    Scolaris, 


Kilkeiiny,    Ireland. 
Fritsch. 

Jcanthostoma,  Credner  (Fig.   213).     Skull    25-35  cm.  long,   sharply  para- 
bolic  in  outline,  externally  pitted.     Orbits  relatively  small,  rounded,  placed 


Uroconipbis  imnde.''/ordii,  Huxley. 
Goal  Measnres  ;  KilkPiiiiy,  Ireland. 
Caudal  vertebrae,  l/i  (after  Huxley). 


Fig.  211. 


Keraterpeton  crassum,  Fritsch.     Lowei  Permian  ;  Nürschan 
Bohemia.     Restored.     Vi  (after  F'ritsch). 


Aii,    \j}."-h^.^,, 


Fio.  213. 

Palatal  aspect  of  skull  of  Acanthoahnna 
voraz,  restored.  i/j  (after  Cre<Iiier).  A, 
Orbit ;  N,  Internal  iiares ;  J'ni.r,  Pi-e- 
niaxilla ;  Mx,  Maxiila ;  (Jul,  Quadrato- 
jngal  ;  PSph,  Parasjiheuoid  ;  /V,  Pterj'- 
Koid. 


in   posterior   half  of    the  skull,  and  with  sclerotic   ring.     All  bones   of  the 
buccal  cavity  set  with  teeth.     Lower  Permian  ;  Saxony. 


Family  '2.     Aistopodidae.      Miall.     (Aistopoda.) 

Body  serpentiform,  withaut  either  limhs  or  arckes  foi'  their  supparf.  Vertehrae 
coustrided  amphicoelous  cylinders.  Teeth  simple,  cmical,  hollou:  Bibs  slender, 
with  one  or  two  processes.     Carboniferous  and  Permian. 


128 


AMPHIBIA 


CLASS  II 


DoUchosoma,  Huxley  (?  Phlegethontia,  ?  Molgophis,  Cope),  (Fig.  214).     Skull 
jj^^  relatively  small,  triangulär,  with  tapering  snout ; 

external  bones  smooth,  and  median  ones  niore 
or   less  fused.     Premaxillae  very  small.     Over 
150  vertebrae,  and  total  length  upwards  of  1  m. 
Neural    spines    atrophied.       Ribs    slender,    the 
foremost  ones  angularly  beut,  later  ones  straight. 
Dermal  armature  not  observed.     Goal  Measures  ; 
Kilkenny,  Ireland.     Lower  Permian  ;   Bohemia. 
Ophiderpeton,  Huxley  (Fig. 
215).       Skull    imperfectly 
known,      shorter     and     more 
obtuse    than     in    Bolichosoma. 
Ribs  slender,  resembling  inter- 
muscular  bones  of  fishes,  with 
dorsal    and   ventral   processes. 
Ventral  scutes  small,  oat- 
shaped ;    dorsal    ossicles    sha- 
green-like.      0.   brownriggi, 
Huxley,  from   the  Irish   Goal 
Measures,     40-60    cm.     long. 
Five    smaller    species    known 
from  the  Permian  of  Bohemia. 


Fig.  214. 

DoUchosoma  longissimum,  Fritsch. 
Lower  Permian ;  Nürschan,  Bohemia. 
Restored.    3/j. 


Fig.  215. 

Ophiderpeton  granii- 
losum,  Fritsch.  Rib. 
6/i.  Permian ;  Bo- 
hemia. d.  Dorsal ; 
V,  Ventral  process. 


Sub-Order  C.     TEMNOSPONDYLI.     Zittel. 

Vertebrae  composed  of  several  pieces,  usually  of  the  rhachitomous  type,  sometimes 
erribolomerous.  Basioccipital  region  usually,  and  carpus  and  tarsns  always  ossified. 
Teeth  with  radially  infolded  walls.     Garboniferous  to  Lower  Trias. 

Archegosaurns,  v.  Meyer  (Figs.  196,  203,  216,  217).  Total  length  up- 
wards of  rö  m.  Skull  in  the  young  obtusely  triangulär,  scarcely  longer 
than  broad,  but  becoming  greatly  elongated  in  the  adult,  with  broad,  anteriorly 
rounded  snout.  External  bones  radially  sculptured,  sensory  canals  feebly 
marked.  Orbits  situated  in  about  the  middle  of  the  skull  in  the  young,  and 
in  hinder  portion  in  mature  individuals ;  sclerotic  ring  of  20-23  plates. 
Anterior  nares  elongate.  Postorbitals  triangulär,  supratemporals  large, 
lachrymals  long  and  narrow,  basioccipital  region  not  ossified,  palatal  vacuities 
large.  Parasphenoid  and  pterygoids  toothless,  vomer  with  one  or  two  pairs' 
of  relatively  large  teeth,  and  maxillae,  premaxillae,  and  palatines  each  with  a 
Single  series  of  teeth.  Dentine  deeply  and  simply  folded  in  lower  half  of  the 
crown.  Denticles  of  branchial  arches  observed  in  young  individuals.  In  the 
caudai  region  stout  chevron  bones  are  attached  to  the  hypocentra,  and  inter- 
calated  between  these  are  two  wedge-shaped  pieces  (Fig.  197). 

The  interclavicle  is  rhomboidal,  about  half  as  long  as  tlie  skull,  and  radially 
sculptured.  Clavicles  triangulär,  with  short  posterior  pedicle ;  coracoid  and  scapula 
ossified.  Fore-limb  less  strongly  developed  than  the  liind,  and  with  fonr  digits. 
Ventral  armouring  of  small,  overlapping,  transversely  elongated  scales,  keeled,  and 
pointed  at  one  end  (Fig.  193,  E). 

In  H.  von  Moyer's  elaborate  Monograph,  published  in   1858,  no  less  than  271 


ORDER  I 


STEGOCEPHALIA 


129 


exainples  from  the  Lower  Permian  of  Lebach,  near  Saarbrücken,  are  described,  of 
wliich  102  are  figured.  The  remains,  lacking  iisually  the  tail,  occur  here  in  siderite 
nodales.     A.  decheni,  v.  Meyer. 

Spamgmites,  Fritsch  ;  Discosaurus,  Credner  (Fig.  193,  G),     Lower  Permian  ; 

Saxoiiy  and  Bohemia. 

Chelidosaurus,  Fritsch. 
Like  ArchegosauruSj  but 
with  broader  and  shorter 
skull,  and  no  lachrymals. 
Lower  Permian ;  Bohemia. 
C.  wanyi,  Fritsch. 

Aäinodon,  Gaudry  (Fig. 
218).  Basiocciput  ossified. 
Vomers  each  with  one  large 


lor 


FIG..216. 

Archegosaurus  decheni,  v.  Meyer.  Lower  Permian ;  Lebach,  near 
Saarbrücken.  Young  individual  with  traces  of  gill  arches.  i/i  (after 
H.  V.  Meyer). 


Fig.  217. 

Archegosaurus  decheni,  v.  Meyer. 
Skull  of  adult  individual,  1/2«  Per- 
mian ;  Lebach,  near  Saarbrücken. 
Pmx,  Premaxilla  ;  Mx,  Maxiila  ;  La, 
Lachrymal;  Prf,  Prefrontal ;  Ptf, 
Postfrontal ;  Por,  Postorbital ;  St, 
SO,  Supratemporals ;  Sq,  Squamosal ; 
Pa,  Parietal ;  QuJ,  Quadrato-jugal ; 
Ep,  "Epiotic"  (=Supratemporal). 


tooth  and  numerous  riigosities.  Yertebrae  rhachitomous.  Lower  Permian 
of  Autun,  France,  and  Ehenish  Prussia. 

Gaudrya,  Cochleosaurus,  Fritsch.  Lower  Permian ;  Nürschan,  Bohemia. 
Euchirosaurus,  Gaudry.     Permian;  France. 

Sclerocephalus,  Goldfuss  (Onchiodon,  Gein. ;   JFeissia,  Branco).      Over  1   m. 

VOL.  II  K 


130 


AMPHIBIA 


CLASS  II 


long.      Skull   rouiuled   anteriorly,  orbits 


in 


Fio.  218. 


Actinodon  frossanU,  Gaudry.     Perinian  ;  Muse,  near  Antun,  France. 
Palatal  aspect  of  skull,  with  lower  jaws.    '-2/5  (after  Gaudry). 


hiiider  third,  anterior  nares  far 
forwards,  external  bones 
coarsely  sculptured.  Pala- 
tines  with  minute  teeth, 
maxillae  and  premaxillae 
with  a  series  of  large, 
conical,  vertically  grooved 
teeth.  Dentine  deeply 
folded.  Vertebrae  rhachi- 
tomous.  Coracoid  ex- 
panded,  with  concave  pos- 
terior bord  er;  scapulalong, 
•  slender,  tapering.  Ventral 
scales  oat-shaped.  Lower 
Permian  ;  Khenish  Prussia 
and  Saxony. 

Melosaurus,  Chalco- 
saurus,  v.  Meyer ;  Zygo- 
saurus,  Eichwald ;  Platyops, 
Trautschold.  Permian; 
Russia. 

Dendrerpeton,  Owen. 
Goal  Measures;  Nova 
Scotia  and  Bohemia. 

IVimerorhachis,      Zatra- 


EryopA  megacephalus,  Cupe.     Pcrniian  ;  Texas. 
.1,  Lateral  aspect  of  skull.     1/5.     jK,  Portion  of  the  vertebral  column.     C,  Caudal  vertebrae.     1/4  (after  Cope). 


ORDER  I 


STEGOOEPHALIA 


131 


chis,   Dissorophus,   Acheloma,    Anisodexis,    Cope.       Permian ;    Texas    aiid    New 
Mexico. 

Ert/ops,  Cope  {Ehachitomus,  Epicordylus,  Parioxijs,  Cope),  (Fig.  219).  Largest 
of  North  American  Stegocephalians.  Skull  40-60  cm.  long,  and  30-46  cm. 
wide  at  occiput,  elongated  triangulär,  with  somewhat  tapering  snout.  Orbits 
round,  relatively  small,  placed  in  hinder  half  of  the  skull.  Anterior  nares 
large,  widely  separated.  Cranial  bones  rugose,  sutures  indistinct.  Para- 
sphenoid  very  thick,  dagger-shaped.  On  the  palatine  two  large  conical  teeth. 
Maxilla  and  premaxilla  with  teeth  of 
various  sizes.  Teeth  sharply  conical,  on 
the  top  smooth,  at  the  base  ribbed. 
Vertebrae  rhachitomous.  Caudal  vertebrae 
few  in  number,  the  posterior  ones  fused 
into  a  triangulär  piece,  tapering  acutely 
behind.  Ribs  strong,  those  of  the  sacrum 
very  broad  and  short.  Permian ;  Texas 
and  New  Mexico. 

Cricotus,  Cope.  Total  length,  3  m. 
General  form  elongate,  with  triangulär 
skull  and  short,  stout  limbs.  Sjiout 
narrow,  orbits  large,  elongated  oval, 
situated  near  the  middle  of  the  skull. 
External  bones  faintly  sculptured,  sensory 
canals  conspicuous,  parietal  foramen  large. 
Teeth  conical,  of  unequal  size.  Presacral 
vertebrae  composed  of  horseshoe  -  shaped 
pleurocentra  and  hypocentra,  the  former 
alone  supporting  the  neural  arch.     In  the 

Caudals     the     pleurocentra    and     hypocentra        Micropholisgranulata,  0\veni>i>.    Trias;  Table 

form  complete   rings,   and    both   elements  tCfÄdo.';?/;^^'):''"'" '''"'"■ 
take   part   in  support  of   the  neural   arch, 

but  the  haemal  arch  is  borne  exclusively  by  hypocentra.      Permian ;  Texas 
and  Illinois.     C.  heteivcUtus,  Cope. 

Diplovertebrojij  Fritsch  (Fig.  198).  Imperfectly  known.  Lower  Permian; 
Bohemia.  Brachyops*  Owen  ;  Gondwanosaurus,  Lyddeker.  Trias  (Gondwana 
Beds) ;  East  India. 

Bothriceps,  Huxley.  Skull  triangulär,  with  very  large  parietals,  and 
coarsely  sculptured  plates.  Anterior  nares  far  forwards.  Teeth  acutely 
conical,  vertically  grooved.     Trias ;  Australia  and  South  Africa. 


tiu.  lii'O. 


Sub-Order  D.     STEREOSPONDYLI.     Zittel. 

Vertebrae  completely  ossified,  slighüy  amphicoelous,  somefimes  centrally  perforated 
for  passage  of  the  notocJwrd.  Basiocäpital  region  ossified  ;  sensory  canals  forming  a 
lyra  hetween  the  orbits  and  anterior  nares.  Teeth  with  complicated  infolding  of  the 
dentine. 

Family  1.     Gastrolepidotidae.     Zittel. 

Ventral  urmour  consisting  of  elongated  bony  scutes.  liadial  prolangations  of  pulp 
cavity  only  moderately  branched.     Carboniferous  and  Permian. 


132 


AMPHIBIA 


Anthracosaurus,  Huxley. 


PlG.  221. 

Cross-section  of  tooth  of  Loxovima  allmani, 
Huxley,  iiear  the  base.  Enlarged.  Goal 
Measures  ;  Norlhuuiberland  (after  Embleton 
and  Abbey). 


Skull  broadly  triangulär,  36  cm.  long,  externally 
pitted.  Orbits  very  small,  situated  in  hinder 
third  of  the  skull.  Teeth  externally  furrowed, 
of  nearly  uniform  size.  Vomer  toothless, 
palatines  with  a  large  tooth,  and  several  of 
smaller  size.  Dermal  scales  externally  con- 
vex,  sharpened  at  the  ends.  Goal  Measures  ; 
Northumberland.     Ä.  russelli,  Huxley. 

Loxomma,  Huxley  (Figs.  199,  221).  Like 
the  preceding,  but  orbits  very  large,  irregu- 
larly  oval,  and  teeth  of  unequal  size.  Goal 
Measures  ;  Northumberland  and  Bohemia. 

Eosaurus,  Marsh.  Known  only  by  a  few 
detached  amp'hicoelous  vertebrae.  Goal 
Measures ;  Nova  Scotia. 

Macromerion,  Fritsch.  Imperfectly  known. 
Permian ;  Bohemia. 


Family  2.     Labyrinthodontidae.     {Euglypta,  Miall.) 

Ventral  armouring  and  sderotic  ring  absent.  Pedoral  plates  large,  coarsely 
sculptured.  Infoldings  of  the  dentine  completely  labyrinthodont.  Ä  few  excessively 
developed  teeth  present  on  the  palatines,  and  sometimes  on  the  vomer  and  Symphysis  of 
lower  jaw.     Trias. 

Trematosaurus,  Braun  (Fig.  222).  Skull  elongated  triangulär,  about  25 
cm.  long,  with  orbits  near  the  middle.  Teeth  present  on  jaw-bones,  palatines, 
and  vomer,  and  inner  border  of  posterior  nares 
fringed  with  small  denticles.  A  pair  of  greatly 
enlarged  teeth  present  on  Symphysis  of  lower 
jaw,  and  behind  these  a  supplementary  row  of 
small  teeth.  Two  large  vomerine  tusks  in  advance 
of  the  posterior  nares,  and  three  or  four  palatine 
ones  behind  the  same.  Interclavicle  rhomboid, 
with  posterior  pedicle.  Abundant  in  the  Bunt- 
sandstein  of  Bernburg.      T.  hrauni,  Burm. 

Metopias,  v.  Meyer  (Metoposaurus,  Lydekker), 
(Fig.  223).  Skull  large,  broadly  triangulär,  with 
elliptical  orbits  in  anterior  half,  and  large  naria] 
openings  Nasals  shorter  than  frontals  and 
parietals.  Pectoral  plates  very  large.  Ribs  very 
powerful,  distally  expanded.  Dentition  weak, 
teeth  strongly  flüted  externally,  especially  at  the 
base,  with  but  slight  internal  foldings.  Teeth 
apparently  arranged  like  those  of  Capitosaurus. 
Keuper ;   Würtemberg. 

Capitosaurus,  Münst.  (Figs.  224,  227).  Skull  with  muzzle  often  broad 
and  obtusely  rounded.  Orbits  small,  behind  the  middle  of  skull.  Nasals 
of  equal  size  with  the  frontals  or  larger.  A  small  auditory  notch  adjacent 
to  the  so-called  epiotic.  One  or  two  powerful  tusks  present  on  vomer  in 
front  of  the  internal  nares  and  on  palatines  behind  the  same.     Between  the 


Flu.  222. 

Skull  of  Trematosauncs  brauni,  Bur- 
iiieist.  Buntsandstein ;  Bernburg. 
1/4  (after  Burmeister). 


ORDER  I 


STEGOCEPHALIA 


133 


vomer  and  premaxillae  is  an  aperture  to  give  play  to  the  two  median  tusks 
of  the  lower  jaw.     Keuper     """         '  ^  .     ~-    . 


Würtemberg,  Franconia,  Silesia. 


Fig.  224. 

Metopias  diagnostims,  v.  Meyer.  Ven- 
tral aspect  of  skeletal  fragment.  Keuper ; 
Hahnweiler,  near  Stuttgart,  l/g  (after 
E.  Fraas). 


Fig.  223. 

Capitosaurus  nasidus,  v.  Meyer.     Buntsandstein  ; 
Bernburg.     Dorsal  aspect  of  skull. 


GtnJ^ 


Fig.  225 


Cydotosaurus  robushis,  v.  Meyer.     Keuper  ;  Feurerbach, 
near  Stuttgart.     Palatal  aspect  of  skull. 


Cydotosaurus,  Fraas  (Fig.  225).  Similar  to  Capitosaurus,  except  that  the 
auditory  notch  is  closed  behind  by  the  union  of  the  external  supratempora 
with  the  prosquamosal.     Keuper  :  Würtemberg. 


1 


134 


AMPHIBIA 


CLASS  II 


Mastodonsaurus,  Jaeger  (Figs.  204,  206,  226).  Largest  of  all  Labyrintho- 
donts,  skull  1*25  m.  long,  depressed,  and  with  large  orbits  behind  the 
middle.  External  bones  sculptured,  sensory  canals  prominent.  Premaxillae 
pierced  for  the  passage  of  the  two  greatly  enlarged  teeth  at  Symphysis  of 
lower  jaw.  Vomers  with  a  pair  of  tusks  in  front  of  the  posterior  nares,  and 
another  near  the  hinder  margin  ;  palatines  with  a 
Single  series  of  large  teeth.  Dentine  excessively 
complicated.  Interclavicle  rhomboidal,  clavicles 
triangulär,  all  strongly  sculptured.  Ischium  very 
large,  pubis  small,  ilium  elongated,  and  articulating 
with  the  sacral  ribs.  Limbs  very  imperfectly 
known,    and    dermal    armour    not  ^_ 

observed.       The   most    perfect    re- 
mains  are  from  the  Lettenkohle  of 


Fig.  226. 

Skull  of  Mastodonsmcrus  giganteus,  Jaeger.  A, 
Orbit ;  N,  External  nares ;  X,  Opeiiings  for  the 
passage  of  tlie  tusks  of  lower  jaw ;  Pmx,  Pre- 
niaxilla ;  Mx,  Maxilla ;  Na,  Nasal ;  La,  Lachrymal ; 
P/r,  Prefrontal;  Fr,  Frontal;  Ptf,  Postfrontal; 
Pa,  Parietal ;  PtO,  Postorbital ;  Sq,  Squamosal ; 
SO,  Supratemporal ;  Ep,  Epiotic ;  J,  Jugal ;  Qj, 
Quadrato-jugal ;  ExO,  Exoccipital  (after  E.  Fraas). 


Fig.  227. 

Lower  jaw  of  Capito' 
saur^is  nasut^l,s,  v' 
Meyer.  Trias);  Bern- 
burg. 


Footprints  of  Cheirotheriinn 
barthi,  Kaup.  Buntsandstein ; 
Hessberg,  near  Hild  berghausen. 
i/e  (after  Owen). 


Gaildorf  and  Oedendorf  in  Würtemberg.  Fragments  occur  also  in  the  Upper 
Trias  of  England  and  India,  and  possibly  also  in  the  Buntsandstein  of  Alsace 
and  the  Black  Forest. 

Lahyrinthodon,  Owen.  Upper  Trias  ;  England.  Bhytidosteus,  Owen. 
Karoo  Formation ;  Orange  Free  State.  Pachygonia,  Gonioglyptus,  Huxley. 
Trias ;  East  India. 

Footprints. — Stegocephalian   footmarks   are   not    uncommon   in    the    Goal 


ORDER  III  URODELA  135 

Measures  of  Nova  Scotia,  Pennsylvania,  Kansas,  and  elsewhere.  They  occur 
also  in  the  Rothliegendes  of  Thuringia,  Saxony,  and  Bohemia ;  in  the  Karoo 
Formation  of  South  Africa,  and  the  Connecticut  Valley  Trias.  More  notable 
still  are  the  Buntsandstein  localities  in  Thuringia  (Fig.  228)  and  Franconia, 
and  those  of  the  English  and  Franconian  Keuper.  The  impressions  always 
occur  along  stratification  planes,  and  on  removal  of  the  superjacent  layer  the 
counterpart  appears  in  relief,  and  is  usually  accompanied  by  a  series  of  fossil 
mud-cracks.  Most  of  these  tracks  are  five-toed,  although  some  occur  in  which 
the  manus,  which  is  invariably  of  smaller  size  than  the  pes,  has  but  four  digits. 


Order  2.     GYMNOPHIONA.     {Apoda,  Oppel.) 

Vermiform  amphibia  covered  with  small  scales,  arranged  in  transverse  rings, 
and  without  limhs.  Vertehrae  amphicoelous,  with  persistent  notochord.  Cranium 
ossified ;  maxillae  and  palatines  with  small,  hackwardly  curved  teeth.  Rihs  weaUy 
developed.     Pedoral  and  pelvic  arches  ahsent. 

The  Coecilians  constitute  a  small  group  restricted  to  the  South  American 
and  Indo-African  tropics,  and  are  unknown  in  the  fossil  State. 


Order  3.      URODELA.^     (Caudata ;  Batrachia  gradientia.) 

Elongate  amphibia  with  naked  skin,  usually  with  two  pairs  of  shm't  limhs  and 
'perennial  tail,  luith  or  vjithout  external  gills.  Cranium  without  supraoccipital,  post- 
orhitals,  and  supratemporals.  Vertehrae  usually  completely  ossified.  No  parietal 
foramen.     llio-sacral  conneäion  acetabular. 

Urodeles  are  distinguished  from  Stegocephalians  chietly  by  their  naked 
body,  solid  vertehrae,  extremely  short  ribs,  and  peculiarities  in  the  conforma- 
tion  of  the  skull  and  pectoral  arch.  The  vertehrae  may  be  either  amphicoelous 
or  opisthocoelous,  are  rarely  pierced  for  the  notochord,  and  have  weakly 
developed  spinous  and  transverse  processes. 

The  skidl,  which  is  broad,  flattened,  and  anteriorly  rounded,  remains  partly 
cartilaginous  even  in  the  adult,  and  both  membrane  and  cartilage  bones  are 
among  its  components.  The  cranial  roof  is  formed  by  the  parietal,  frontal, 
and  prefrontal  Clements,  adjoining  which  on  either  side  are  the  large  temporal 
fossae  and  orbits.  The  nasal  capsule  is  sometimes  covered  by  ossified  nasals, 
and  sometimes  remains  cartilaginous.  The  anterior  and  lateral  margins  of 
the  skull  are  formed  by  the  premaxillae  and  maxillae,  but  the  latter  are 
sometimes  entirely  wanting.  In  the  basioccipital  region  only  the  exoccipitals 
are  ossified,  and  the  auditory  capsule  remains  either  cartilaginous  or  partially 
ossified,  being  covered  by  a  thin,  transversely  elongated  squamosal.  Jugal 
and  quadrato-jugal  are  absent,  the  quadrate  is  small,  and  only  its  articular 
extremity  is  ossified.  Parasphenoid,  vomers,  and  pterygoids  are  conspicuous 
on  the  under   side  of  the   skull,  but  the  palatines  are  frequently  atrophied. 

^  Meyer,  IL  von,  Zur  Fauna  der  Vorwelt,  pt.  2.  Frankfurt,  1845.— Salaniandrinen  aus  der 
Braunkohle,  etc.  (Palaeontogr.  vol.  VII.),  1860  ;  also  vol.  II.  p.  70,  and  vol.  X.  p.  2.92.— Strauch, 
A.,  Revision  der  Salamandridengattungen.  St.  Petersburg,  1870. —  Wiedersheim,  R.,  Salamandrina 
perspicillata,  Versuch  einer  vergleichenden  Anatomie  der  Salaniandrinen.  Wurzburg,  1875. — Das 
Kopfskelet  der  Urodelen.  Leipzic,  1877.— Dollo,  L.,  Note  sur  le  Batracien  de  Bernissart.  (Bull. 
Mus.  Roy.  d'Hist.  Nat.  Belg.  vol.  III.),  1884.     [ffijlaeobatrachns.] 


136 


AMPHIBIA 


CLASS  II 


Small,  acutely  conical  pleurodont  teeth  (Fig.  229)  are  present  in  both  jaws, 

^  and   also  on  the 

Tmx  ^"^au  vomer  and   pala- 

tines. 

The  peäoral 
arch  remains  for 
the  most  part  car- 
tilaginous.  Only 
the  ventral  por- 
tion  of  the  sca- 
pula,  together 
withthe  proximal 
ends  of  the  cora- 
coid  and  precora- 
coid  unite  to  form 
a  common  osseous 
plate.  In  the 
pelvic  arch  only 
the  ilium  and 
large  ischia  are 
regularly  ossified, 
the  pubis  remain- 
ing,  as  a  rule,  car- 
tilaginous.  The 
limbs  do  not  difFer 
essentially  from 
those  of  Stego- 
cephalians,  and 
the  carpus  and 
tarsus  exhibit 
various  degrees 
of  ossification. 

Urodeles    are 

fresh  -  water     in- 

habitants,  or  live 

Fig.  229.  in    damp    shady 

Skull  of  Cryptobranchus  japonicus,  v.  d.  Hoeveii.      ^.Dorsal;   and  B,  Palatal  places      On      thc 

aspects.     C,  Lower  jaw.     Pmx,  Preinaxilla  ;   Mx,  Maxilla ;   Na,  Is'^asal ;   Prf,  Pre-  -i        -,  i     •   +• 

frontal;  Fr,  Frontal;  Pa,  Parietal;  OSph,  Orbitosphenoid ;  ExO,  Exoccipital ;  Qxi,  lanü,       SUDSlStmg 

Quadrate;  Sq,  Squamosal ;    Pt,   Pterygoid ;    PSph,   Parasphenoid ;    Vo,  Vomer;    G,  ^„      -wT-nT-me       o-n« 

Palatinevacuityri^,  Externalnares.   !  ^"      WOrms,      gas- 

tropods,  small 
aquatic  animals,  and  fish  spawn.  Fossil  remains  occur  only  in  fresh-water 
deposits,  and  are  always  very  rare.  But  one  Mesozoic  skeleton  is  known,  and 
the  few  Tertiary  genera  are  scarcely  distinguishable  from  those  now  living. 


Sub-Order  A.     ICHTHYOIDEA. 


Vertebrae  amphicoelous,  with  persistent  remnants  of  notochord.     Three  pairs  of 
external  gills,  or  in  their  absence  a  persistent  branchial  apert'ure. 
small,  without  distinct  lids.     Aquatic  habitat. 


ORDER  IV 


ANURA 


137 


To  this  group  probably  belong  the  unique  Hylaeöbatrachus  croyi,  Dollo, 
from  the  Wealden  of  Bernissart,  Belgium, 
earliest  known  Urodele;  and  also  the  giant 
Salamander  from  the  Miocene  of  Oeningen, 
Baden  {Andrias  scheuchzeri,  Tschudi,  Fig.  230), 
originally  described  by  Scheuchzer  as  Homo 
diluvii  testis.  The  latter  genus  attains  a  length 
of  about  1  m.,  and  differs  but  slightly  from 
the  recent  Cryptohranchus,  v.d.  Hoeven  (Megalo- 
batrachus,  Tschudi),  of  Japan.  A  somewhat 
smaller  species  (Andrias  tschudii,  v.  Meyer) 
occurs  in  the  Miocene  lignite  of  Rott,  near 
Bonn. 

Sub-Order  B.     SALAMANDRINA. 

Vertebrae  opisthocoeloiis,  completely  ossified, 
Witliout  gills  or  gill  aperture ;  well-developed  eye- 
lids  always  present.  Maxillae  present ;  both  jaws 
toothed. 

Several  genera  resembling  recent  newts  and 
Salamanders  occur  sparsely  in  the  Upper  Eocene 
(or  Oligocene)  of  Quercy  and  Sansan  in  France  ; 
Lower  Miocene  of  Rott  and  Erpel,  near  Bonn ; 
and  the  Bohemian  Tertiary.  Among  these  may 
be  mentioned  Polysemia,  Heliarchon,  and  Arch- 
aeotriton,  v.  Meyer;  Megalotriton,  Zittel;  and 
possibly  Molge  (Triton)  itself. 


Fig.  230. 

Andrias  scheuchzeri,  Tschudi. 
Miocene  ;  Oeningen,  Baden.     1/ 


Order  4.     ANURA.     (Ecaiidata,  Batrachia  salentia}) 

No.ked,  tailless  amphibia  of  compact  form,  and  with  usually  procoelous 
vertebrae.  Caudal  vertebrae  coalesced  into  a  slender  elongate  piece,  or  coccyx.  Fubis 
and  ischium  fused.  Carpus  and  tarsus  ossified,  and  the  two  bones  forming  the 
proximal  row  of  the  latter  greatly  elongated.  Development  by  metamorphosis.  No 
gills  in  the  adidt.     Eio-sacral  attachment  extremely  pre-acetabular. 

The  vertebral  column  consists  in  the  adult  of  from  ten  to  twelve  usually 
procoelous  vertebrae,  all  of  which  with  the  exception  of  atlas  and  coccyx  bear 
stout  transverse  processes.  Short  ribs  are  present  in  the  Discoglossidae,  but 
are  elsewhere  wanting  in  this  order.  All  the  post-sacral  vertebrae  become 
fused  during  metamorphosis  into  a  single  caudal  piece,  or  coccyx  or  urostyle 
(Fig.  231). 

The  skull  (Fig.  232)  is  flattened,  with  very  large  orbits.  Parietals  and 
frontals  are  fused  into  an  elongated  pair  of  median  Clements,  in  front  of 
which    lie    the    ring-shaped    sphenethmoid    (or   orbitosphenoid)    and   nasals. 

^  Meyer,  H.  von,  Zur  Fauna  der  Vorwelt,  pt.  1.  Frankfort,  1845. — Also  articles  in  Palaeontogr. 
vol.  II.  p.  70  ;  vol.  VII.  p.  46  :  and  Neues  Jahrb.  für  1843,  pp.  395,  580  ;  1845,  p.  798  ;  1846, 
p.  351  ;  1847,  p.  192;  1851,  p.  78  ;  1852,  pp.  57,  465  ;  1853,  p.  162  ;  1858,  p.  202  ;  and  1863, 
p.  187.  —  Wolterstorff,  W.,  Ueber  fos.sile  Frösche  insbesondere  Palaeobatrachus  [with  complete 
bibliography].     (Jahresb.  naturw.  Vereins  Magdeburg  für  1885,  '86),  1886-87. 


138 


AMPHIBIA 


CLASS  II 


The  basioccipital  region  and  auditory  capsules  are  ossified ;  the  parasphenoid 
is    inverted    T-shaped;    and    the    pterygoid,    palatine,    and    jugal   are    well 

developed,  the  last-named  joining  the 
maxilla  in  front  and  quadrato- jugal  behind. 
Small,  bristle-like  pleurodont  teeth  occur  on 
the  jaw-bones  and  vomer,  or  may  be  entirely 
wanting. 

The  pectoral  arch  (Fig.  233)  is  remark- 
able  for  its  large-sized  scapular  element, 
which  is  commonly  divided  and  incom- 
pletely  ossified,  and  joins  with  the  coracoid 
and  precoracoid.  The  sternum  is  also  large 
and  more  or  less  cartilaginous ;  of  its  three 
ossified  portions,  the  anterior  is  called  the 
omosternum ;  the  middle  piece  is  the 
sternum  proper ;  and  the  posterior,  which 
terminates  in  a  semicircular  cartilaginous 
expansion,  is  the  xiphisternum.  Ulna  and 
radius  are  fused,  the  two  rows  of  small 
carpals  are  ossified,  and  the  manus  is  pro- 
vided  with  four  digits. 

The  three  elements  of  the  pelvic  arch  are 
coössified  at  the  acetabulum  on  either  side 
to  form  a  single  piece,  which  joins  its  fellow 
in  a  median  Symphysis.  Tibia  and  fibula  are  fused,  the  two  bones  forming 
the  proximal  row  of  the  tarsus  (astragalus  and  calcaneum)  are  much  elongated, 
and  the  pes  has  five  digits. 

Fossil  Anura  are  rare,  the  oldest  clearly  identifiable  remains  occurring  in 
the  Eocene  of  East  India  {Oxyglossus  pusillus,  Owen  sp.)  and  Wyoming.     A  few 


Vertebral  colunin  ofRana  esmlenta.  A,  Dorsal 
and £,  Ventral aspect.  i/i-  a(Z,  Atlas;  d,  Trans 
verse  process ;  z,  Anterior ;  z',  Posterior  zygapo 
physes  ;  sc,  Sacral  vertebra  ;  coc,  Coccyx. 


Fio.  232. 

Skull  ot  Rana  esmlenta,  Linn.  A,  Froni  above.  B,  P^roin  the  side.  C,  From  below.  Pmx,  Premaxilla  ;  Mx, 
Maxilla ;  Na,  Nasal ;  FrPa,  Fronto-parietal ;  Sq,  Squaniosal  (tympanic) ;  QuJ,  Quadrato-jusal ;  hy,  Hyoid  ;  md, 
Lowerjaw;  PSph,  Parasphenoid;  Vo,  Vomer;  PI,  Palatine;  Pt,  Pterygoid;  Eth,  Ethmoid  (Orbitosplienoid); 
P,  Petrosal. 

genera  are  known  from  the  Upper  Eocene,  Oligocene,  and  Lower  Miocene  of 
Southern  France,  Northern  Italy,  and  Germany,  Bana  and  Palaeohatrachus 
being  the  commonest  forms.  Phosphatised  mummies  both  of  JRana  and  Bufo 
occur  in  the  Eocene  (or  Oligocene)  Phosphorites  of  Quercy.     The  Miocene 


ORDER  IV  ANUEA  139 

lignites  near  Bonn  yield  not  only  numerous  perfect  skeletons,  but  impressions 


Pectoral  arch  of 
Sana  temporaria ; 
ost,  Omosternum ; 
ssc,  Suprascapula ; 
prc,  Precoracoid . 
C07-,  Coracoid ;  st, 
Sternum  ;  Xst,  Xi- 
phisternum.  (The  dotted  fjarts  are  cartilag 


^^ 


Fig.  234. 


Fig.  235. 


Larvae  of  Palaeo- 
hatnxchiis  fritschii, 
Wolterstorff.  Mio- 
cene Lignites ;  Kal- 
tennordheini,  Rhön. 
Vi  (after  Wolterstorff 
and  Meyer). 


l'alaeobatrachus  grandipes,  Giebel.    Lignite  ;  Orsberg  in 
Siebengebirge.    2/3  (after  Wolterstorff). 


of  tadpoles  belonging  to  the  genus  Palaeo- 
batrachus,  Tschudi,  are  plentiful  (Figs. 
234,  235). 

Perfect     skeletons     of     large     toads 

(Latonia    seyfriedi,    v.    Meyer;    Pelophilus 

agassizi,    Tschudi)    are    known    from    the 

Miocene    freshwater   marls    of    Oeningen, 

The  equivalent  deposits  of  Günzburg,  Sansan,  and  Sinigaglia  likewise 

yield  remains  of  tailless  Batrachians.     Pleistocene  Anura,  like  late  Tertiary 

Urodeles,  belong  exclusively  to  recent  genera. 

VERTICAL  RANGE  OF  AMPHIBIANS. 


Baden. 


s 

es 
1 

Devonian. 
Carboniferous. 

1 
1 

Trias. 
Jura. 

1 

i 

a 

i 

Oligocene. 
Miocene. 

Pliocene. 
Recent. 

Stegocephalia     . 
Lepospondyli     . 
Temnospondyli 
Stereospo7idyli  . 

Gymnophiona 

Urodela 

Ichthyoidea 
Salamandrina  . 

Anura  . 

= 

1 

i 

! 

- 

- 

! 

i 

^ 

— 

'ZIZ. 

[The  preceding  chapter  011  Amphibia  has  been  translated  and  extended,  without  altering 
the  Classification,  by  Dr.  E.  C.  Gase,  of  the  State  Normal  School  at  JSIilwaukee,  Wisconsin. 
— Editor.] 


140  REPTILIA  CLASS  in 


Olass  3.    REPTILIA.^ 

Cold-hlooded,  naked,  scaly  or  armoured  vertehrates,  with  exdusively  pulmonary 
respiration,  and  terrestrial  or  aquatic  in  habit.  Skeleton  completely  ossified  ;  emhryo 
with  amnion  and  allantois,  development  witliout  metamorphosis.  Skull  with  a  single 
basioccipital  condyle.     Two  pairs  of  limhs  usually  present ;  metapodal  bones  separate. 

In  external  appearance  reptiles  closely  resemble  amphibiaris,  but  are 
vastly  more  differentiated  as  a  class,  and  are  mostly  of  greater  size.  Their 
extremities  exhibit  great  diversity  in  structure  and  function.  Among  the 
Pterosauria  the  anterior  limb  is  transformed  into  a  volant  organ  provided 
with  a  flexible  wing  membrane ;  among  Dinosaurs  the  appendicular  skeleton 
attains  a  size  and  ponderosity  unsurpassed  by  the  largest  land  mammals  ;  in 
marine  reptiles  the  limbs  are  paddle-shaped ;  and  in  most  Lacertilians,  Thero- 
morphs,  Crocodiles,  and  Dinosaurs  the  limbs  are  ambulatory ;  while  the  only 
apodal  forms  occur  among  the  Squamata  (snakes  and  certain  lizards). 

The  integument  of  reptiles  is  tougher  than  that  of  amphibians,  and  a  more 
or  less  perfect  exoskeleton  is  often  developed  in  consequence  of  the  ossifica- 
tion  of  the  cutis  and  cornification  of  the  epidermis.  The  former  may  give 
rise  to  bony  scutes  overlapping  one  another  in  a  tectiform  manner,  or  to 
larger  bony  plates  with  closely  applied  edges,  arranged  so  as  to  form  a  more 
or  less  continuous  shield,  as  in  tortoises. 

The  vertebral  col'umn  is  always  ossified,  although  remnants  of  the  notochord 
may  persist  in  the  centra.  In  all  cases  where  both  pairs  of  limbs  are  present, 
cervical,  dorsal,  sacral,  and  caudal  regions  are  distinguishable,  and  the  dorsal 
series  may  be  often  subdivided  into  thoracic  and  lumbar  vertebrae.  The 
vertebral  centra  exhibit  all  gradations  between  amphiplatyan,  amphicoelous, 
procoelous,  and  opisthocoelous ;  and  the  union  between  the  centra  and  their 
neural  arches  may  be  cartilaginous,  sutural,  or  by  anchylosis.  The  neural 
spines  are  always  ossified.  Sometimes  they  are  enormously  produced,  in 
other  cases  {Chelonio.)  laterally  expanded  and  united  with  dermal  plates.  The 
anterior  zygapophyses  have  facettes  looking  inward  and  upward  which  are 
overriden  by  the  post-z3^gapophyses  of  the  vertebra  immediately  in  front ;  and 
in  the  Squamata  and  Dinosauria  the  vertebrae  are  still  further  conjoined  by  a 
median  process  given  off  from  the  anterior  (zygosphene)  or  posterior  (hyposphene) 
end  of  the  neural  arch,  and  received  into  a  notch  of  the  arch  next  behind 
(zygantrum)  or  in  front  (hypantrum).  The  cervicals  generally  bear  short 
tranverse  processes  (diapophyses)  attached  to  the  sides  of  the  centra,  but  in 
the  dorsal  series  these  processes  are  given  off  from  the  neural  arches.  The 
haemapophyses  or  "  chevron  bones"  of  the  caudal  series  sometimes  form  true 

^  Literature : 

Baur,  G.,  On  the  pliylogeuetic  arrangement  of  the  Sauropsicla  (Journ.  Morphol.  vol.  I.  No.  1), 
1887. — Bemerkungen  über  die  Osteologie  der  Schläfengegend  der  höheren  Wirbelthiere  (Anat. 
Anz.  vol.  X.  p.  315),  1894-. — Cope,  E.  D.,  Synopsis  of  the  extinct  Batrachia,  Reptilia  and  Aves 
of  North  America  (Trans.  Amer.  Phil.  Soc.  vol.  XIV.),  1869. — On  the  homologies  of  the  posterior 
cranial  arches  in  the  Reptilia  {ibid.  vol.  XVII.),  1892. — Fürbringer,  M.,  Zur  vergleichenden 
Anatomie  des  Brustschulterapparats  und  der  Schultermuskeln.  IV.  Theil.  (Zeitschr.  für  Naturwis- 
semsch.  vol.  XXXIV.),  1900. — Hoffiminn,  C.  K.,  Die  Reptilien,  in  Bronn's  Classen  und  Ordnungen 
des  Thierreichs,  vol.  VI.  pt.  3,  1879-89.— Z?/(feMer,  R.,  Catalogue  of  the  fossil  Reptilia  and 
Amphibia  in  the  British  Museum,  vols.  I.-IV.  London,  1888-90.— J/^j/er,  //.  von,  Zur  Fauna,  der 
Vorwelt.  Pt.  I.-IV.  Frankfort,  1845-60.— Oji'ew,  R.,  Report  on  British  fossil  Reptilia  (Rept. 
Brit.  Assoc.  Adv.  Sei.  9th  Meet.  p.  43),  1839.  Also  ibid.  llth  Meet.  p.  60,  1841.— A  History  of 
British  fossil  Reptiles  [Reprint].     London,  1849-84. 


PHYLUMViii  VERTEBRATA  141 

haemal  arches,  or  their  halves  may  unite  in  a  single  piece.  Among  existing 
reptiles  there  are  never  more  than  two  sacral  vertebrae,  but  the  sacrum  of 
üinosaurs  sometimes  comprises  as  many  as  ten,  and  that  of  Pterosaurs  from 
three  to  six.  When  more  than  three  are  present,  however,  they  are  usually 
coössified  into  a  single  piece  (synsacrum).  Only  among  Ophidians,  Pythono- 
morphs,  and  Ichthyosaurs  is  there  no  differentiated  sacral  region.  Small 
cuneiform  intercentra  (hypocentra)  may  be  inserted  between  the  cervicals, 
caudals,  and  a  portion  or  all  of  the  dorsals. 

All  the  vertebrae  with  the  exception  of  the  posterior  caudals  may  bear 
ribs.  Cervical  ribs  are  as  a  rule  short,  and  have  the  distal  end  expanded  in 
hatchet-shaped  fashion.  When  a  sternum  is  present,  the  ribs  with  which  it 
is  connected  facilitate  the  distinction  between  cervical  and  dorsal  regions. 
The  posterior  dorsal  ribs  have  free  extremities,  and  lumbar  vertebrae  are 
always  non-costiferous.  Cervical  ribs  are  usually  double-headed,  and  the 
centra  exhibit  two  facettes  for  their  attachment.  JDorsal  ribs  may  be  either 
Single  or  double-headed,  and  in  Chelonians  are  remarkable  for  their  union 
with  the  broad  costal  plates  of  the  carapace.  Many  of  the  Reptilia  develop 
so-called  abdominal  ribs,  which  are  ossifications  of  the  connective  tissue,  and 
correspond  to  the  ventral  scales  of  Stegocephalians. 

The  shidl  agrees  more  nearly  with  that  of  birds  than  amphibians  in  its 
general  features,  and  the  ossification  of  the  primordial  cranium  is  much  more 
complete  than  in  the  latter  group.  The  investing  membrane  bones  are  so 
intimately  united  with  true  cartilage  bones  that  a  distinction  is  often 
impossible.  The  basiocciput  articulates  with  the  atlas  by  means  of  a  single, 
sometimes  tripartite  condyle,  formed  either  by  the  basioccipital  alone,  or  by 
this  bone  in  conjunction  with  the  exoccipitals.  Both  the  basioccipital  and 
supraoccipital  may  be  excluded  from  the  borders  of  the  foramen  magnum.  Of 
the  bones  forming  the  auditory  capsule,  the  proötic  (petrosal)  is  situated  in 
front  of  the  lateral  parts  of  the  occipital  region ;  it  occurs  as  a  separate  bone, 
and  its  front  margin  is  pierced  for  the  third  brauch  of  the  trigeminus  nerve. 
The  opisthotic  is  often  fused  with  the  exoccipital,  and  the  epiotic  with  the 
supraoccipital.  Besides  the  usual  auditory  opening,  or  fenestra  ovalis,  there  is 
commonly  a  fenestra  rotunda  ;  the  position  of  the  former  is  either  between  the 
exoccipitals,  or  between  the  opisthotic  and  proötic.  At  the  base  of  the  skull 
immediately  in  front  of  the  basioccipital  occurs  the  basisphenoid,  a  true  carti- 
lage bone,  in  place  of  a  parasphenoid ;  and  this  is  continued  in  front  by  the 
presphenoid. 

Alisphenoids  and  orbitosphenoids  are  as  a  rule  wanting,  or  are  replaced 
by  downwardly  directed  processes  of  the  parietals  and  frontals.  The  last- 
named  bones  are  usually  of  large  size,  and  may  be  either  paired  or  unpaired. 
Applied  to  the  parietals  on  either  side  is  a  large  squamosal,  which  takes  part 
in  the  posterior  cranial  border  and  that  of  the  supratemporal  vacuity.  The 
lower  end  of  the  squamosal  usually  abuts  against  the  quadrate,  which  is 
always  strongly  developed,  and  bears  a  condyle  for  articulation  with  the  lower 
jaw.  Sometimes  the  squamosal  is  divided,  the  upper  portion  being  identified 
as  the  prosquamosal  or  supratemporal.  In  Sphenodon  the  two  components 
later  become  coalesced. 

Among  the  Squamata  the  quadrate  is  movably  articulated  with  the  squa- 
mosal, being  united  by  ligaments  only  (Streptostylica) ;  but  among  other 
reptiles  it  is  rigidly  attached  to  the  skull  by  sutures  (Monimostylica).     The 


142 


REPTILIA 


CLASS  III 


quadrato-jugal,  wheii  present,  lies  above  and  anterior  to  the  quadrate, 
connecting  it  with  the  jugal.  The  latter  joins  the  hinder  end  of  the  maxilla, 
and  forms  with  it  the  inferior  border  of  the  orbit.  The  bony  arcade 
separating  the  orbits  and  temporal  fossae  is  formed  by  either  the  postorbital 
alone,  or  by  that  bone  in  connection  with  the  postfrontal  and  jugal.  The 
prefrontals  are  usually  well  developed,  and  adjoin  the  frontals  ori  either  side ; 
sometimes  they  exclude  the  latter  from  the  superior  border  of  the  orbit,  and 
assist  the  lachrymals  in  forming  its  anterior  border.  The  nasal  capsule  is 
roofed  by  the  prefrontals  and  nasals,  and  bounded  anteriorly  by  the  paired  or 
unpaired  premaxillae.  The  latter,  together  with  the  maxillae,  complete  the 
front  rim  of  the  upper  jaw. 

The  chief  modifications  of  the  skull  amongst  different  Orders  consist  in  the 
rearrangement  of  the  bones  of  the  postero-lateral  regions  into  separate  bars 
or  arcades,  aecompanied  by  the  formation  of  temporal  vacuities  (Fig.  236). 


Fig.  230. 


Diagrani  of  tlie  cranial  roof  in  a  Stegocephalian,  various  types  of  Reptiles,  and  a  Bird,  showing  modifications 
in  the  postero-lateral  region.  A,  Mastodonsaurus,  1/15.  B,  Generalised  Theromorph  or  Sauropterygian,  passinj;- 
with  slight  inodification  into  the  Chelonian  (sutures  dotted  to  denote  inconstancy  in  fusion  of  elements).  (', 
Ichthyosaurus,  1/20.  D,  Generalised  Rhynchocephalian,  Dinosaurian,  Crocodilian,  or  Ornithosaurian.  A', 
Generalised  Lacertilian.  F,  Generalised  Bird.  fr,  Frontal ;  j,  Jugal ;  l.  Lateral  temporal  vacuity ;  la,  Lachry- 
mal ;  mx,  Maxilla  ;  n,  Narial  opening ;  na,  Nasal ;  0,  Orbit ;  p«,  Parietal ;  pmx,  Premaxilla  ;  2>^/,  Prefrontal ; 
ptf,  Postfrontal ;  pto,  Postorbital ;  qj,  Quadrato-jngal ;  qu,  Quadrate  ;  s,  Supratemporal  vacuity  ;  sq,  Squamosal. 
Vacuities  shaded  with  vertical  lines,  cartilage  bones  dotted  (from  A.  S.  Woodward). 

Among  Theromorpha,  Sauropterygia,  Chelonia,  and  Ichfhyosauria,  a  supratemporal 
vacuity  is  produced  by  the  squamosal  being  thrust  outward  to  form  with  the 
quadrato-jugal  and  jugal  a  broad  arch  along  the  cheek.  A  further  stage  is 
exhibited  by  the  Rhynchocephalians,  Dinosaurs,  Crocodiles,  and  Pterosaurs, 
where  the  a^rrangement  of  the  squamosal  is  the  same,  but  the  broad  arch  of  the 


PHYLUMviii  VERTEBKATA  143 

cheek  plates  is  pierced  by  a  lateral  temporal  vacuity,  leaving  a  narrow  bar 
above  and  another  narrow  bar  below.  Among  Lacertilians  this  lower  bar 
becomes  lost,  and  finally  among  Snakes  both  bars  disappear,  leaving  but  one 
extensive  vacuity.  For  those  Orders  of  reptiles  distinguished  by  having  two 
temporal  arches,  namely,  the  Rhynchocephalians,  Crocodilians,  Dinosaurs,  and 
Pterosaurs,  Cope  has  proposed  the  term  Archosauria.  This  group  properly 
includes  also  the  Squamata,  in  which  one  or  both  arches  have  become  obsolete. 

On  the  under  side  of  the  skull  the  pterygoid  forms  the  connection 
between  quadrate,  basisphenoid,  and  palatines.  It  varies  considerably  in  size 
and  shape  amongst  the  different  Orders,  according  as  the  quadrate  and  maxillo- 
palatine  apparatus  are  movably  or  rigidly  united  with  the  wall  of  the  skull. 
In  many  forms  a  transverse  bone  (ectopterygoid)  is  developed  between  the 
pterygoid  and  maxilla,  and  a  slender  column-like  bone  called  the  columella  or 
epipterygoid,  extends  between  the  parietal  and  pterygoid  (Fig.  253).  Some- 
times  a  flat  expansion  of  the  maxillae  joins  with  the  palatines,  and  enters 
with  these  bones,  the  vomers,  premaxillae,  and  pterygoids  into  the  formation 
of  a  secondary  bony  palate.  The  lower  jaw  is  composed,  as  in  Amphibians, 
of  a  dentary,  splenial,  coronoid,  angular,  and  surangular  formed  from  mem- 
brane  ossifications,  and  an  articular  formed  from  Meckel's  cartilage.  Crocodiles 
have  the  lower  jaw  as  well  as  many  of  the  cranial  bones  hollow  and  j^neu- 
matic. 

Teeth  are  wanting  only  among  Chelonians  and  isolated  representatives  of 
other  groups.  As  a  rule  they  occur  extensively  on  the  jaw  bones,  and  in 
some  cases  also  in  the  palatines,  pterygoids,  and  vomers.  The  greater  number 
are  single-rooted,  those  with  divided  roots  being  very  exceptional.  The 
crown  consists  chiefly  of  dentine,  covered  with  a  layer  of  enamel ;  cement 
enters  but  slightly  into  its  composition,  and  vasodentine  is  entirely  wanting. 
The  form  is  usually  sharply  conical,  either  erect  or  recurved,  but  there  are 
many  other  varieties,  such  as  depressed,  hemispherical,  or  even  pavement-like ; 
some  have  bevelled  edges,  or  are  chisel-  or  spada-shaped,  and  a  few  are  multi- 
cuspidate.  Pleodont  teeth  have  solid  crowns,  as  contrasted  with  coelodont, 
which  grow  from  persistent  pulps.  Thecodont  or  socketed  teeth  are  inserted  in 
alveoli,  acrodoiit  fused  with  the  supporting  bone  along  the  outer  rim  or  top, 
and  pleurodont  teeth  are  developed  laterally  along  the  flange-like  inner  rim  of 
the  jaw. 

With  the  exception  of  Snakes  and  certain  Lacertilians,  two  pairs  of  limbs 
are  always  present.  In  the  pedoral  arch  the  principal  bones  are  the  coracoid 
and  scapula,  the  former  usually  exceeding  the  latter  in  size,  and  forming 
either  alone  or  in  connection  with  the  scapula  the  glenoid  cavity  for  the 
humerus.  Clavicular  and  interclavicular  elements  may  or  may  not  be  present, 
and  the  same  is  true  of  the  precoracoid,  which  occurs  usually  as  an  anteriorly 
(lirected  process  of  the  coracoid.  The  scapulae  are  normally  directed  upward 
and  backward,  and  are  well  separated  by  the  clavicular  arch  when  present. 
The  interclavicle  (or  episternum),  may  be  rhomboidal,  cruciform,  or  J-sbaped, 
and  differs  from  the  adjacent  bones  in  being  of  membranous  origin.  Posterior 
to  the  interclavicle  is  usually  a  flat,  rhomboidal,  or  aspidate  sternum,  to  which 
the  anterior  dorsal  ribs  are  attached  by  means  of  intermediate  pieces.  Very 
frequently  the  sternum  is  wanting ;  when  present  its  antero-lateral  margin  is 
always  applied  against  the  coracoid,  and  when  absent  the  coracoids  uiiite  in  a 
median  Symphysis  or  are  joined  together  by  ligaments. 


144  KEPTILIA  class  iii 

The  appendicular  skeleton  is  constituted  essentially  as  in  Amphibians. 
In  the  fore-limb  the  humerus  of  some  fossil  forms  is  pierced  at  its  distal  end 
by  one  or  two  foramina,  as  in  certain  mammals ;  but  among  living  reptiles 
this  character  appears  only  in  Sphenodon.  The  ulna  sometimes  exceeds  the 
radiusin  length,and  is  sometimes  provided  proximally  with  an  olecranon  process. 
The  carpus  consists  always  of  two  rows  of  bones,  of  which  the  proximal  contains 
two  or  three,  and  the  distal  from  three  to  six  elements ;  occasionally  these 
rows  are  separated  by  one  or  two  centralia.  The  bones  of  the  manus  undergo 
excessive  modifications  correlating  with  their  function,  There  are  commonly 
from  two  tp  five  digits,  and  among  Ichth/osaurs  even  more  than  five.  The 
third  and  fourth  digits  usually  possess  a  larger  number  of  phalanges  than  the 
rest.  The  most  generalised  type  of  manus  and  pes  is  found  among 
Chelonians. 

Numerous  modifications  occur  also  in  the  pelvic  region  and  posterior  limb. 
A  sacrum,  consisting  normally  of  two  vertebrae,  is  present  in  all  reptiles  with 
the  exception  of  Snakes,  Ichthyosaurs,  and  Pythonomorphs.  Among  Snakes 
the  pelvis  is  either  entirely  wanting,  or  represented  by  vestigial  ischia ;  and 
rudimentary  ilia  are  present  among  apodal  Lizards.  All  other  reptiles  have  a 
pelvis  composed  of  the  three  usual  elements,  and  as  a  rule  they  all  take  part 
in  the  formation  of  the  acetabulum.  The  ilium  is  often  much  extended 
antero-posteriorly.  The  ischia  are  generally  larger  than  the  pubes,  and  both 
pairs  converge  ventrally  in  front,  and  join  in  median  symphyses.  A  decided 
bird-like  aspect  is  observed  in  the  pelvis  of  Dinosaurs,  owing  to  the  downward 
and  backward  extension  of  the  greatly  elongated  ischium,  and  the  anterior 
Prolongation  of  the  dorsal  part  of  the  ilium.  The  bind  limb  closely  resembles 
the  fore  in  most  cases.  One  or  two  trochanters  may  occur  on  the  proximal 
porti'on  of  the  femur,  and  there  are  generally  two  rows  of  tarsals.  The 
Sauropsida  (Reptiles  and  Birds)  difFer  from  mammals  in  having  the  ankle-joint 
between  the  two  rows  of  tarsals,  and  never  between  the  tibia  and  proximal 
tarsals.  Various  modifications  of  the  hind  limb  occur,  which  are  noted  in  the 
discussion  of  the  different  groups. 

Habitat.  —  Their  respiration  being  exclusively  pulmonary,  reptiles  are 
adapted  to  a  terrestrial  or  amphibian  existence.  Even  the  small  number  of 
marine  Chelonians  and  Lacertilians  visit  the  shores  periodically  for  the  pur- 
pose  of  depositing  their  eggs.  Among  extinct  forms,  Ichthyosaurs,  Sauro-  ■ 
pterygians,  and  Pythonomorphs  were  truly  marine,  and  provided  with  paddle- 
shaped  extremities.  The  majority  of  fossil  reptiles,  however,  were  land  forms  ; 
some  appear  to  have  been  arboreal,  and  the  Pterosaurs,  as  their  name  implies, 
were  volant,  or  at  least  capable  of  gliding  through  the  air.  There  is  reason  to 
suppose  that  Dinosaurs  were  viviparous,  as  is  known  to  be  true  of  Ichthyo-^ 
saurs,  and  some  of  the  former  were  of  bipedal  galt. 

Over  3500  recent  species  of  reptiles  have  been  described,  a  number  greatly 
exceeding  the  known  fossil  forms.  The  latter,  however,  exhibit  far  greater 
diversity  in  structure  than  living  species,  and  hence  a  knowledge  of  their 
Organisation  is  indispensable  for  an  understanding  of  the  class.  The  earliest 
undoubted  reptilian  remains  (Proferosauria)  are  of  Lower  Permian  age,  and 
although  not  plentiful  here,  numerous  forms  are  known  from  the  Upper  Per- 
mian of  Europe,  North  America,  and  South  Africa.  The  culmination  of  the 
class  occurred  during  the  Jura-Trias,  after  which  Reptiles  steadily  declined. 

Taxonomy. — The  Separation  between    Reptiles  and  Amphibians  was  first 


ORDER  I  RHYNCHOCEPHALIA  146 

efFected  by  Blainville  in  1816,  and  approved  by  Merrem  in  1820,  but  a  satis- 
factory  Classification  was  impossible  until  after  the  researches  of  Owen, 
Huxley,  von  Meyer,  Marsh,  Cope,  Osborn,  Baur,  and  others  had  vastly 
increased  our  knowledge  of  fossil  fornis.  Universal  agreement  does  not  by 
any  means  obtain  regarding  the  limitations  of  the  difFerent  groups,  but  most 
modern  authorities  are  in  favour  of  recognising  nine  independent  Orders,  as 
follows  : — Bhynchocephalia,  Squamata,  Ichthyosauria,  Sauroptertjgia,  Therornorpha, 
Chelonia,  Crocodüia,  Dinosauria,  and  Pterosauria.  Of  these  the  Permian 
Rhynchocephalians  include  the  earliest  and  most  primitive  forms,  and  may 
be  regarded  in  a  broad  sense  as  ancestral  to  all  Archosauria  (or  reptiles  with 
two  temporal  arches),  as  well  as  Aves. 


Order  1.     RHYNCHOCEPHALIA.^ 

Lacertiform  reptiles  with  amphicoelous  vertebrae,  somefimes  pierced  for  the  noto- 
chord.  Upper  and  lower  temporal  arcades  well  defined.  Quadrate  fixed,  and 
buttressed  hy  the  pterygoids,  which  extend  forwa.rd  to  the  vomer  ;  premaxillae  paired. 
Mandibular  Symphysis  usually  ligamentous ;  teeth  acrodont.  Sternum  p'esent  ; 
sacrum  composed  of  two,  or  in  the  Pelycosauria  of  three  vertebrae.  Limbs  ambu- 
latory,  pentadadyle.     Dermal  armour  of  corneous  scales. 

The  existing  genus  Sphenodon  (Hatteria)  of  New  Zealand  is  the  sole 
survivor  of  an  ancient  and  primitive  order  of  reptiles  which  attained  its 
maximum  specialisation  in  the  Trias,  and  whose  earliest  representatives 
{Proterosauria)  resemble  the  Microsaurian  Stegocephalia  in  noteworthy  respects. 
This  primitive  Permian  group  also  occupies  the  cleft  between  Squamata, 
Crocodilia,  and  Dinosauria,  and  is  in  all  probability  ancestral  to  birds  through 
a  primitive  Dinosaur-avian  stem. 

The  body  in  Rhynchocephalians  is  lizard-like,  long-tailed,  sometimes  scaly ; 
the  vertebral  centra  are  amphicoelous  or  amphiplatyan,  with  persistent  noto- 
chord,  and  often  with  small  intercentra  (hypocentra).  The  neural  arches  are 
well  ossified,  and  zygapophyses  and  diapophyses  usually  conspicuous.  With 
the  exception  of  the  anterior  cervicals  and  posterior  caudals,  all  the  vertebrae 
bear  strong  single-headed  ribs.  Several  or  numerous  longitudinal  series  of 
abdominal  ribs  occur  between  the  limb  girdles,  and  correspond  to  the  ventral 
armouring  of  Stegocephalians. 

The  skull  (Fig.  237)  is  remarkable  for  the  large  size  of  the  orbits  and 
temporal  vacuities.     There  are  always  two  temporal  arcades,  the  upper  one 

^  Literature  : 

Baur,  G.,  Palaeohatteria  and  the  Proganosauria  (Araer.  Journ.  Sei.  [3],  vol.  XXX VII.  p.  310), 
1889, — Boidenger,  G.  A.,  On  British  remains  of  Homaeosaiirus,  with  remarks  on  the  Classification 
of  the  Rhynchocephalia  (Proc.  Zool.  Soc.  p.  167),  1891. — Credner,  H.,  Ueber  Palaeohatteria  und 
Kadaliosaurus  (Zeitschr.  deutsch,  geol.  Ges.  vol.  XL.  p.  488),  1888.— Do/Zo,  Z.,  Premiere  note  sur 
le  Simaedosaurus  d'Erquellinnes  (Bull.  Mus.  Roy.  d'Hist.  Nat.  Belg.  vol.  III.),  1884.  —  Sur 
l'identite  des  geures  Champsosaurus  et  Simaedosaurus  (Bull.  Soc.  Belg.  Geol.  vol.  V.  p.  151),  1891. 
— Günther,  A.,  Contribution  of  the  anatomy  of  Hatteria  (Phil.  Trans,  vol.  CLVII.),  1867. — Huxleif, 
T.  H.,  On  Hyperodapedon,  etc.  (Quar.  Journ.  Geol.  Soc.  vols.  XV.  p.  435  ;  XXV.  p.  138  ;  XLIII. 
p.  675),  1859-87.— Zorfei!,  Z.,  Les  reptiliens  fossiles  du  bassin  du  Rhone  (Arch.  Mus.  d'Hist.  Nat. 
Lyon,  vol.  V.),  1892.— J/eyer,  H.  von,  Zur  Fauna  der  Vorwelt  (vols.  HL,  IV.),  1857-60.— Äe^/ey, 
H.  G.,  On  Proterosaiirus  (Phil.  Trans,  vol.  CLXXVIII.  p.  187),  1887 .—Siebearock,  F.,  Zur 
Osteologie  des  Hatteria-Kopfes  (Sitzber.  Akad.  Wiss.  Wien,  vol.  CIL  pt.  1),  189S.— Wagner,  A., 
Saurier  aus  dem  lithographischen  Schiefer  (Abhandl.  Bayer.  Akad.  Wiss.  vols.  VI.,  VII.,  IX.), 
1852-61. 

VOL.  II  L 


146 


EEPTILIA 


CLASS  III 


Por 


being  formed  by  the  postorbital  and  ßquamosal,  and  the  lower  arcade  by 
the  quadratojugal  and  jugal.  The  latter  bone  is  always  fixed,  and 
buttressed  by  the  pterygoids,  which  extend  forwards  to  the  vomer.     The  brain 

cavity  is  of  small 
size,  and  roofed  by 
the  narrow  parietals, 
between  which  and 
the  pterygoids  is  a 
vertical  columella 
(epipterygoid).  A 
parietal  foramen  is 
generally  present. 
The  paired  external 
nares  are  almost 
terminal  in  position. 
Vomer,  palatines,and 
pterygoids  together 
form  an  extensive 
bony  palate.  Acro- 
dont  teeth  occur  in 
regulär  series  on  the 
narrow  premaxillae, 
maxillae,  and  man- 
dibles,  and  in  some 
cases  the  vomer  and 
palatines  are  also 
dentigerous.  Occa- 
sionally  the  teeth  are 
inserted  in  shallow 
alveoli,    and    verv 


Fig.  237 


New    Zealand.      Lateral,    palatal, 


The  pedoral  arch 


Sphenodon   fnnctatiis,    Gray.      Recent 
posterior,  and  superior  aspects  of  skull.     2/g.    (^a,  Orbit;  aug,  Angular ;  art, 
Articular ;  bo,  Basioccipital ;  eh,  Internal  nares ;  d,  Deiitary  ;  cxo,  Exoccipital ; 
r.  Frontal ;  ju,  Jugal ;  7,-,  Surangular  ;  mx,  Maxiila  ;  N,  External  narial  opeiiiug  ;    rarclv    are     absent 
na,  Nasal;  opo,  Opistliotic  ;  pa,  Parietal;  pl,  Palatine  ;  pmx,  Preinaxilla ;  por,       ,  '^  ■, 

Postorbital;  prf,  Prefrontal  ;  pt,  Pterygoid  ;   ptf,  Postfrontal;   qu,  Quadrate;    altOgetHer. 
quj,    Quadrato-jiigal  ;    S,    Suprateniporal    vacuity ;    so,    Supraocoipital ;    sq, 
Squainosal ;  vo,  Vomer.) 

is  incompletely 
ossified.  The  scapula  is  represented  by  an  elongated  rectangular  bone, 
and  the  inner  border  of  the  small  elliptical  coracoids  remains  cartilaginous. 
The  clavicle  is  a  slender  bent  rod  connecting  the  scapula  with  a  large 
rhomboidal  or  T-shaped  interclavicle,  which  overlies  the  cartilaginous 
sternum.  The  distal  end  of  the  humerus  is  pierced  in  the  fossil  forms  by 
an  entepicondylar  foramen,  but  in  Sphenodon  both  entepicondylar  and 
ectepicondylar  foramina  or  grooves  occur.  In  general  the  articular  surfaces 
of  the  humerus,  radius,  and  ulna  are  not  completely  ossified.  Five  distinct 
Clements  occur  in  the  distal  row  of  the  carpus,  and  two  centralia  are  often 
present.     The  extremities  are  pentadactylate. 

The  yelvic  arch  consists  of  a  small,  nearly  vertical  ilium,  a  discoidal  pubis 
with  obturator  notch,  and  a  somewhat  expanded  ischium,  which  remains 
separated  from  the  pubis.  Both  pubis  and  ischium  are  imperfectly  ossified 
among  the  earlier  forms.  The  hinder  is  somewhat  longer  than  the  fore-limb, 
and  resembles  that  of  Lacertilians  and  Theromorphs. 


orüp:r  I 


RHYNCHOCEPHALIA 


14' 


Sub-Order  1.     PROTEROSAURIA.     Seeley.     (Proganosauria,  Baur.) 

Abdominal  ribs  s7naU,  arranged  in  several  longitudinal  series.  Pubis  and  ischium 
imperfectly  fused.  Fi/th  metatarsal  not  dissimilar  from  fhe  rest.  Marginal  teeth  in 
a  Single  uniform  series. 

The  sub-order  is  of  interest  as  comprisiiig  some  of  the  most  primitive  and 
most  ancient  reptiles  known  to  science.  They  are  regarded  by  many  authors 
as  ancestral  not  only  to  the  Sphenodon  group,  but  to  all  Archosauria,  or  reptiles 
with  two  cranial  arches.  There  is  much  reason  to  suppose  that  from  these 
forms  also  a  Dinosaur-avian  stem  was  evolved  in  the  Permian,  from  which 
birds  have  come  down  to  us. 


Family  1.     Proterosauridae. 

Maxillae,  premaxillae,  and  mandibles  with  a  series  of  large  conical  teeth,  either 
acrodont  or  implanted  in  shallow  alveoli,  arid  smaller  teeth  present  on  the  palaiines 
and  vomer.  Interdavide  elongate,  with  a  rhombic  expansion  at  its  anterior  end. 
Permian  and  Trias. 

Palaeohatteria,  Credner  (Fig.  238).  Body  lizard-like,  about  25  cm.  long. 
Vertebral  centra  in  the  form  of  delicate  constricted  amphicoelous  cylinders, 


s 


Fig.  238. 


Palaeohatteria  longicandata,  Credner.  l.ower  iVriniaii ; 
Saxony.  A,  Skull,  somewhat  distorted,  Vi-  -ß.  Pectoral 
arch.  C,  Pelvic  arch.  D,  Dorsal  vertebra ;  E,  Caudal 
vertebra,  anterior  aspect,  (a,  Acetabnluni ;  cl,  Clavicle  ; 
cor,  Coracnid  ;  /,  Feninr;  h,  Hunierus  ;  ic,  Intercentrmn  ; 
icl,  Interclavicie ;  il,  Iliuni ;  jn,  Jugal ;  la,  Lachrynml ; 
n,  Pedicle  of  neural  arch  ;  na,  Nasal ;  o,  Obturator  notch ; 
pmx,  Premaxilla  ;  jwr,  Postorbital  ;  prf,  Prefrontal ;  pn, 
Pubis ;  quj,  Squaniosal  and  quadrate ;  vo,  Vomer  (dis- 
placed);  z,  Z.vapopliysis.  Orbit  overlaid  by  displaced 
facial  bones  of  the  right  side),  (after  Credner). 


with  persistent  notochord  ;  small  intercentra  occur  between  all  in  advance  of 


148  EEPTILIA  class  iii 

about  the  sixth  caudal,  and  single-headed  ribs  borne  by  all  the  vertebrae  as 
far  as  the  seventh  caudal.  Abdominal  ribs  represented  by  numerous  small 
oat-shaped  scutes.  Premaxillae  small,  with  three  or  four  recurved  teeth. 
Inferior  border  of  orbit  formed  by  jugal  alone.  Digits  clawed.  Habits 
probably  aquatic,  as  indicated  by  the  comparatively  unossified  extremities  of 
limb  bones.     Lower  Permian  (Rothliegendes) ;  Niederhässlich,  near  Bonn. 

Kadaliosaurus,  Credner.  A  land  form  accompanying  the  preceding ;  limb 
bones  completely  ossified  proximally  and  distally,  with  spongy  interior. 
Extremities  much  longer  than  in  PalaeohaUeria  ;  humerus  and  femur  of  equal 
length,  but  metacarpals  shorter  than  metatarsals. 

Fi'oterosaurus,  v.  Meyer.  Attaining  a  length  of  TS  m.  Vertebral  centra 
completely  ossified,  and  united  with  their  neural  arches  by  suture.  Inter- 
centra  occur  only  between  the  cervical  vertebrae,  which  are  elongate,  and  bear 
slender  ribs.  Skull  tapering  anteriorly,  its  structure  not  clearly  shown. 
Hind  limb  considerably  longer  than  the  fore,  and  distal  tarsals  less  than  five 
in  number.  Upper  Permian  (Kupferschiefer)  of  Thuringia  and  Hesse,  and 
Magnesian  Limestone  of  Durham,  England.  P.  spemri,  v.  Meyer ;  F.  lincki, 
Seeley. 

Aphelosaurus,  Gervais ;  Haptodus,  Gaudry.  Lower  Permian ;  Autun  and 
Lodeve,  France.     Telerpeton,  Mantell.     Supposed  Trias  of  Elgin,  Scotland. 


Sub-Order  2.     PELYCOSAÜRIA.     Cope.i 

Anterior  teeth  enlarged,  incisor-  and  canine-like,  the  remainder  conical  and 
molariform ;  none  of  the  teeth  with  lateral  cusps,  hut  sometimes  serrated.  Neural 
spines  enormously  developed  in  some  genera.  Sacrum  of  three  vertebrae.  Limbs 
very  short  and  strong. 

Family  1.     Olepsydropidae.     Cope. 

Skull  long  and  narrow,  truncated  posteriorly.  External  nares  separated,  terminal, 
opening  directly  into  the  mouth.  Orbits  large,  round,  placed  behind  the  middle  of  the 
skull ;  supratemporal  vacuity  small,  Quadrate  sm,all,  nearly  enclosed  by  surrounding 
bones.  Anterior  incisor s  and  canines  of  upper  jaw  much  larger  than  other  teeth. 
Numerous  small  conical  teeth  present  on  palatines,  pterygoids,  and  vomer.  Proximal 
tarsals  two  in  number.     Permian. 

Olepsydrops,  Cope.  Neural  spines  of  the  lumbar  and  sacral  regions  greatly 
elevated.  Intercentra  present  between  the  dorsal  and  caudal  vertebrae ; 
anterior  ribs  double-headed,  posterior  single-headed.  Teeth  large,  with  sharp 
cutting  edges.      Permian ;  Texas,  Illinois,  and  Kansas. 

Dimetrodon,  Cope.  Larger  than  the  preceding,  skull  upwards  of  0*5  m. 
long,  and  with  similar  dentition.  Intercentra  present  between  the  dorsals ; 
all  the  ribs  double-headed  from  the  axis  on.  Neural  spines  rising  from  the 
axis  until  in  the  dorsal  region  they  are  many  times  longer  than  the  diameters 
of  the  centra.     Permian  ;  Texas. 

^  Literature  : 

Baur,  G.,  and  Case,  E.  C,  On  the  morphology  of  tlie  skull  of  the  Pelycosauria  and  the  origin  of 
the  Manimals  (Anat.  Anz.  vol.  XIII.  p.  109),  1897. — The  history  of  the  Pelycosauria,  with  a 
description  of  the  genns  Dimetrodon  (Trans.  Amer.  Phil.  Soc.  vol.  XX.  pt.  1),  1899. — Case,  E.  C, 
The  Vertebrates  from  the  Permian  Bonebed  of  Illinois  (Journ.  Geol.  vol.  VIII.  p.  698),  1900. 


ORDER  I 


RHYNCHOCEPHALIA 


149 


Naosaurus,  Cope  (Fig.  239).     DifFers   from   the   last   in   that  the  neural 
spines  bear  transverse  processes.     Per- 
mian  ;  Texas  and  Bohemia. 

Embolophorus^  Theropleura,  Archaeo- 
bolus,  Lysorophus,  Cope.  Permian  : 
Texas.  Stereorachis,  Gaudry  ;  Calli- 
brachion,  Boule  and  Glengeaud.  Per- 
mian ;  Autun,  France.  Known  by  im- 
perfect  remains  apparently  allied  to 
Dimetrodon. 

Sub-Order  3. 
RHYNCHOCEPHALIA  VERA. 

Abdominal  rihs  reduced  tothreerelatively 
large  longitudinal  series  ;  pubis  and  ischium 
well  ossified ;  fifth  metatarsal  very  mucli 
shortened,  and  somewhat  expanded.  Mar- 
ginal teefh  in  one  or  more  uniform  series. 


Fio.  243, 


Hy%)ero(hqmlon    gordoni,    Huxley.     Upper    Trias ; 

Elgin,  Öcotland.  A,  Snperior aspect  of  skull,  i/a- 
li,  Palate.     C,  Mandibular  Symphysis   from   below. 

a,  Orbit;  md,  Mandibular  fork ;  mx,  Maxilla ;  n, 
Nasal ;  pl,  Palatine ;  /imr,  Preniaxilla ;  s,  Supia- 
teniporal  vacuity ;  s',  Lateral  temporal  vacuity), 
(after  Huxley). 


Fig.  239. 

Naosaurus  daviger,  Cope.  Permian ;  Texas. 
Dorsal  \'ertebrae,  anterior  and  lateral  aspects,  I/4 
(after  Cope). 


Family  1.     Rhynchosauridae. 

Skidl  Short  and  broad,  wiih  a  beak-like 
ostrum  formed  by  the  downwardly  curved, 
slender,  toothless  premaxillae.  Mamiibles 
with  a  Single,  and  maxillae  and  palatines 
with  several  longitudinal  series  of  depressed 
conical  teeth.  External  nares  conflueni. 
Trias. 


Hyperodapedon,  Huxley  (Fig.  240).     Body  stout,  upwards   of   2   m.   long. 


150  EEPTILIA  CLAss  iii 

Mandibular  rami  fused  in  a  long  Symphysis,  which  is  slightly  forked  at  its 
toothless  anterior  end ;  posteriorly  with  a  single  series  of  obtuse  teeth. 
Parietal  foramen  and  intercentra  apparently  wanting.  Cervical  vertebrae 
opisthocoelous  ;  limbs  imperfectly  known.  Supposed  Trias  of  Elgin,  Scotland, 
and  Central  India. 

Bhynchosaurus,  Huxley.  Smaller  and  with  fewer  teeth  than  the  preceding  ; 
mandible  toothless  or  with  minute  teeth,  maxillae  with  a  single  row,  and 
palatines  with  a  double  row  of  small  teeth.  Vertebrae  aniphicoelous  ;  ab- 
dominal ribs  well  developed.      Upper  Trias  ;  Shropshire  and  Warwickshii  e. 

Family  2.     Mesosauridae.i 

Small  lacertiform  reptilia,  with  very  numerous,  extremely  long  and  acicular 
teeth  in  the  upper  and  lower  jaws.  Vertebral  centra  aniphicoelous,  with  remnants  of 
the  notochord.  Cervical  vertebrae  vjith  short  hatchet-shaped  ribs.  Dorsal  ribs 
single-headed,  very  thick  Ventral  ribs  well  developed.  Tarsus  with  two  rows  of 
small  bones.     Extremities  with  five  toes. 

Mesosaurus,  Gervais  (Ditrochosaurus,  Gürich).  Karoo  formation  of  South 
Africa. 

Stereosternum,  Cope,  from  the  Permian  or  Lower  Trias  of  Brazil  is  })ossibly 
identical  with,  in  any  case  very  similar  to  Mesosaurus. 

Family  3.     Ohampsosauridae. 

Skull  with  elongated  gavial-like  snout.  Ä  single  series  of  large  conical  teeth 
present  on  the  jaw-bones  and  palatines,  and  irregidar  longitudinal  series  of  minute 
teeth  on  the  vomers,  palatines,  and  pterygoids.  External  nar es  terminal  and  conßueiit. 
Mandibular  rami  suturally  united  at  the  Symphysis.  Only  two  intercentra  present  at 
anterior  end  of  the  neck.  Vertebral  centra  completely  ossified,  slightly  biconmre,  or 
amphiplatyan,  and  suturally  united  with  their  neural  arches.  Cretaceous  and 
Lower  Eocene. 

Champsosaurus,  Cope  (Simaedosaurus,  Gervais).  Large  aquatic  reptiles 
attaining  a  length  of  2*5  m.  Premaxillae  elongated  into  a  gavial-like  rostrum  ; 
cervical  ribs  short  and  double-headed  ;  abdominal  ribs  stout.  Humerus  with 
ectepicondylar  groove  instead  of  foramen.  Known  by  fragmentary  remains 
from  the  Laramie  Cretaceous,  and  Lower  Eocene  of  the  United  States,  and  by 
complete  skeletons  from  the  Lower  Eocene  of  France  and  Belgium. 

Family  4.     Sauranodontidae. 

Small  long-tailed  Iihynchocephalia  with  edentulous  jaics  and  beak-like  rostrum. 
Temporal  fossae  small,  parietal  foramen  wanting,  postorbital  very  large,  external  nares 
undivided.  Vertebrae  well  ossified;  second  sacral  rib  distally  divided ;  abdominal 
ribs  stout.  Fore-limb  shorter  than  the  hind,  both  pentadactylate.  Dermal  scales 
rectangular.     Upper  Jura. 

Sauranodon,  Jourdan.  This,  the  solitary  genus,  is  known  by  perfect 
skeletons  from  the  Upper  Jura  of  Cerin,  France.  aS'.  incisivus,  Jourdan,  attains 
a  length  of  about  0*7  m. 

^  Geinitz,  H.  B.,  Siir  Stereosternum  tumidum,  Cope  (Ann.  Soc.  Geol.  Belg.  vol.  XXV.  bis  p.  35), 
1900. —  Woodvmrd,  A.  S.,  On  a  new  specimen  of  Stereosternum  (Geol.  Mag.  [4],  vol.  IV.  p.  145), 
1897. 


ORDER  I 


RHYNCHOCEPHALIA 


151 


Family  5.     Sphenodontidae. 

Vertebrae  amphicoelous,  sometimes  with  persistent  noto- 
chord ;  mtercentra  present  in  cervical  and  caudal  regions. 
Premaxillae  euch  with  a  small  pointed  tooth.  A  singl 
series  of  depressed,  triangulär,  acrodont  teeth  present  on 
maxülae,  mandibles,  and  outer  edge  of  the  palatines  ;  vomer 
toothless.  External  nares  separated  ;  inier damde  T-shaped; 
dermal  scales  subrectangular.     Upper  Jura  to  Recent. 

Ho7naeosaurus,  v.  Meyer  (Sapheosaurus,  v.  Meyer), 
(Fig.  241).  Attaining  a  length  of  between  20  and  40 
cm.,  and  difFering  from  the  recent  Sphenodon  in  that 
intercentra  are  absent  between  the  dorsal  vertebrae, 
ribs  without  uncinate  processes,  and  humerus  not 
pierced  by  entepicondylar  foramen.  Mandibular  rami 
united  at  the  Symphysis  by  ligaments ;  second  sacral 
rib  bifid  distally.  Upper  Jura  (Lithographie  Stone) ; 
Bavaria,  and  Cerin,  France.  Kimmeridgian  of  Hanover, 
and  Purbeckian  of  England.      H.  maximiliani,  v.  Meyer. 

Ardeosaurus,  Acrosaurus,  v.  Meyer ;  Euposaurus, 
Jourdan.  Upper  Jura  (Lithographie  Stone) ;  Bavaria, 
and  Cerin,  France. 

Fleurosaurus,  v.  Meyer  (Anguisaurus,  Münst. ;  Sauro- 
pJiidium,  Jourdan).  Body  serpentiform,  upwards  of 
1'5  m.  long,  the  tail  forming  one-third  the  total  length. 
Snout  tapering  in  front.  Presacral  vertebrae  with 
stout  single-headed  ribs  ;  abdominal  ribs  well  developed. 
Fore-limbs  shorter  than  the  hinder  pair.  Upper  Jura 
(Lithographie  Stone) ;  Bavaria,  and  Cerin,  France.  F. 
muensteri,  Wagner. 

Sphenodon,  Gray  {Hatteria,  Gray).  Inferior 
border  of  the  large  orbits  formed  by  maxilla ; 
external  nares  divided ;  a  single  tooth  on  either 
side  of  the  premaxillary  beak ;  intercentra  present 
between  all  the  vertebrae,  humerus  with  both  entepicondylar  and  ectepicondylar 
foramina  or  grooves.     Recent,  inhabiting  certain  Islands  off  New  Zealand. 


Fig.  241. 

Hnimieosaurus  pulchellns 
Zittel.  Upper  Jura  ;  Kel- 
lieim,  Bavaria.  Ventral 
aspect,  I/o. 


VERTICAL  RANGE  OF  THE  RHYNCHOCEPHALIA. 


Divisious. 

Penniaii. 

Trias. 

Jura, 

Cretaceous. 
Eocene. 

1 

c 

I.    P1IUTERO8AUKIA  .... 
II.   Pelycosauhia    .... 

III.    RHYNCHOCEPHALIA    VeUA. 

1.  Rhynehosaitridae     . 

2.  Mesosauridae  .... 

3.  Champsasauridac    . 

4.  Sauranodontidac     . 

5.  Sphenodontidae 

-"~"~ 

? 

■  '^^ 

152 


REPTILIA 


GL  ASS  III 


Order  2.     SQUAMATA.     (Lepidosauria,  Streptostylica.)  ^ 

Body  elongate,  covered  with  corneous,  or  more  rarely  lüith  dermal  scales  or  scutes. 
Quadrate  movably  attached  to  the  skull ;  the  lower  temporal  arcade  always,  and  upper 
temporal  arcade  frequently  wanting.  Palatal  vacuities  large,  pterygoids  not  in  contad 
with  vomer  ;  external  nares  separated  ;  teeth  acrodont  or  pleurodont.  Vertehrae  well 
ossified,  usually  procoelous,  rarely  amphicoelous  ;  sacral  vertehrae  not  more  than  two  in 
number.  Post-cervical  intercentra  and  abdominal  ribs  wanting ;  dorsal  ribs  single- 
headed.  Limbs  adapted  for  ambulation  or  natation,  absent  only  among  Ophidia  arid 
a  few  Lacertilia. 

This  Order  comprises  Lizards,  Snakes,  and  two  extinct  groups  of  aquatic 
reptiles, — Dolichosauria  and  Pythonomorpha, — the  earliest  clearly  recognised 
members  of  which  occur  in  the  Cretaceous.  The  Sguamata  are  evidently  veiy 
closely  allied  to  Rhynchocephalians,  and  in  all  probability  their  origin  is  to  be 
traced  to  that  group. 


Sub-Order  1.     DOLICHOSAURIA. 

Small,  aquatic,  serpentiform  reptiles,  with  well-developed  lizard-like  limbs  and  limb- 
girdles.  Vertebrae  procoelous,  and  articulated  both  by  zygapophyses  and  zygosphene- 
zygantrum  arrangemeut.  Sacral  vertebrae  not  anchylosed.  Mandibles  with  sutural 
Symphysis.     Teeth  pleurodord. 

The  family  Dolichosauridae  comprises  a  few  genera  from  the  English  Chalk 
and  the  Upper  Cretaceous  of  Istria  and  Dalmatia,  the  largest  of  which  attain 
a  length  of  between  two  and  three  metres.  Dolichosaurus,  Owen,  has  no  less 
than  seventeen  cervical  vertebrae  and  large  hollow  ribs.  Acteosaurus,  Adrio- 
saurus,  Aigialosaurus,  Carsosaurus,  Ponfosaurus,  and  Mesoleptos  are  allied  Istrian 
genera.  Most  of  the  detached  vertebrae  of  Cretaceous  age,  commonly  classed 
as  Ophidian,  are  doubtless  Dolichosaurian.  Like  the  Pythonomorphs,  these 
forms  probably  passed  away  without  leaving  any  post-Cretaceous  descendants. 


Sub-Order  2.     PYTHONOMORPHA.     Cope. 


Lai^ge  marine  reptiles  with  elongate  body  and  two  pairs  of  paddle- shaped  appen- 
dages.     Skull  lizard-like,  elongate,  depressed ;  superior  temporal  arcade  and  pineal 


^  Cope,  E.  D.,  Crocodiles,  Lizards,  and  Snakes  of  North  America  (Ann.  Eept.  Smithsonian  lust., 
1898),  1900. 

2  Literature  : 

Baur,  G.,  Morphology  of  the  skull  of  the  Mosasauridae  (Journ.  Morphol.  vol.  XII.,  No.  1),  1892. 
— Cope,  E.  D.,  The  Reptiliau  orders  of  Pythonomorpha  and  Streptosauria  (Proc.  Boston  Soc.  Nat. 
Hist.  vol.  XII.  p,  250),  1869. — The  Vertebrata  of  the  Cretaceous  Formations  of  the  West  (Rept. 
U.S.  Geol.  Surv.  Territ.  vol.  II.),  1875. — Professor  Owen  on  Pythonomorpha  (Bull.  U.S.  Geol.  Surv. 
Territ.  vol.  IV.  p.  299),  1878. — Guvier,  G.,  Sur  le  grand  animal  fossil  de  la  craie  de  Maestricht 
(Ann.  Mus.  d'Hist.  Nat.  vol.  XII.),  1808. — Dollo,  L.,  Note  sur  l'osteologie  des  Mosasauridae  (Bull. 
Mus.  Roy.  d'Hist.  Nat.  Belg.  vol.  L),  \%%2.—Ibid.  vol.  IV.,  1885.— Nouvelle  Note,  etc.  (Bull.  Soc. 
Belg.  de  Geol.  Pal.  et  Hydro!,  vols.  III.-VII.),  l%9,'d-'d'^.—Gibhes,  R.  W.,  A  Memoir  on  Mosasaurus, 
etc.  (Smithson.  Contr.  Knowl.  vol.  IL),  1864. — Goldfuss,  A.,  Der  Schädelbau  des  Mosasaurus  (Nova 
Acta  Acad.  Caes.  Leop.  Gar.  nat.  cur.  vol.  XXL),  1843. — Leidy,  J.,  Cretaceous  Reptiles  of  the 
United  States  (Smithson.  Contrib.  Knowl.),  1864. — Extinct  Vertebrate  Fauna  of  the  Western  Terri- 
tories  (Rept.  U.S.  Geol.  Surv.  Territ.  vol.  L),  1873. — Marsh,  0.  C,  Characters  of  Mosasauroid 
Reptiles  (Amer.  Journ.  Sei.  [3],  vol.  L),  1871.— Ibid.  vol.  III.  (1872)  ;  and  XIX.  (1880).— Merriam, 
J.  C,  Die  Pythonomorpha  der  Kansas  Kreide  (Palaeontogr.  vol.  XLL),  1894. — Osborn,  H.  F.,  A 
complete  Mosasaur  Skeleton  (Mem.  Amev.  Mus.  Nat.  Hist.  vol.  I.  pt.  4),  1899. — Oioen,  R.,  On  the 


ORDER  II 


SQUAMATA 


153 


foramen  present ;  premaxillae  and  nasal s  fused  into  a  simple  rostrum ;  quadrate 
large,  perforate,  and  nwvahly  attached  to  squamosal  and  prosquamosal ;  parietal  un- 
paired  and  joined  to  the  supraoccipitals  and  proötics  hy  decurved  lateral  processes. 
Mandihidar  rami  united  af  the  Symphysis  hy  ligament,  and  with  a  movable  articulaiion 
behind  the  middle  of  each  ramus.  Teeth  large  and  conical,  fixed  hy  tumid  hases  in 
shallow  alveoli  of  the  jaw-bones  and  pterygoids.  Sderotic  ring  present.  Vertebrae 
procoelous,  cervicals  with  hypapophyses.  Sacrum  wanting ;  sternum  prohahly  never 
ossified  ;  interdavicle  (episternum)  sometimes  present,  but  no  clavicular  arch.  Limh- 
bones  short,  but  the  digits  are  lengthened  hy  an  increased  numher  of  phalanges,  the 
ungual  ones  dawless. 

The  vertehral  column  comprises  115-130  or  perhaps  more  procoelous 
vertebrae,  and  is  sometimes  divisible  into  cervical,  dorsal,  lumbar,  and  caudal 
regions.  The  distinction  between  dorsal  and  lumbar  series  is  not  verv  decided, 
however,  except  that  the  latter  bear  shorter  ribs.  The  transverse  processes 
are  short  and  thick  in  the  pi'ecaudal  vertebrae  for  the  attachment  of  single- 
headed  ribs ;  in  the  caudals  they  are  flattened  and  elongated  but  not  costiferous, 
and  become  obsolete  at  about  the  middle  of  the  tail.  The  neural  arches  are 
always,  even  in  young  individuals,  thoroughly  coössified  with  their  centra ;  the 
neural  spines  are  of  moderate  length,  but  sometimes  notably  elongated  in  the 
posterior  region  of  the  tail.  The  zygapophyses  are  strong  in  the  cervical  and 
anterior  thoracic  region,  but  become  weaker  and  finally  disappear  in  the  tail. 
Y-shaped  haemapophyses  or  chevron  bones  are  present  in  all  the  caudals  with 
the  exception  of  the  first  five  or  more,  to  which  the  name  "  pygals  "  has  been 
given ;  each  chevron  articulates 
only  with  its  own  centrum.  The 
atlas  is  composed  of  a  wedge- 
shaped  intercentrum  below,  and 
two  lateral  pieces  or  neuropo- 
physes,  as  in  lizards,  its  centrum 
being  represented  by  the  odontoid 
process  of  the  axis.  A  wedge- 
shaped  intercentrum  occurs  be- 
tween- the  atlantal  intercentrum 
and  the  axis.  The  axis  and  five 
follow^ing  cervicals  bear  each  a 
more  or  less  stout  exogenous 
hypapophysial  process,  to  the  ex- 
tremity  of  which  is  attached  a 
small,  free  epiphysis,  correspond- 
ing  morphologically  to  an  inter- 
centrum    (Fig.     242).       This     is  fig.  242. 

wanting    in    the    last    cervical,  and  CUdastes  stenops,  Cope.     Upper  Cretaceous ;  Kansas.    An- 

,              ^           .        ,^   .            ,.            ,  terior  cervical  vertebrae.     A,  Froin  the  side.     B,  Froiti  m 

the  process  itsell  IS  rudimentary.  front,  i/"-    (<■.  Centnun;  d,  Transverse  process;  h,  Hypapo- 

Thp      ^h/JJ      (V\iT^       243        244)  pliysial  epiphysis  or  intercentrpi;  /r»^  Hypapophysis ;  prc, 

ine     SKllii     V-T  lg»-      -J^o,      ^tt;  Prezygapophysis  ;  sp,  Neural  spine),  (after  Cope). 

resembles   that   of    Varanus  more 

nearly  than  that  of  other  living  reptiles.     The  parietals,  frontals,  and  pre- 

rank  and  affinities  of  the  Mosasauridae  (Quar.  Jouru.  Geol.  Soc.  vol.  XXXIII.  p.  682),  1877.— Ibid. 
vol.  XXXIV.  (1878),  p.  74:8.— WiUiston,  S.  W.,  On  Mosasaurs,  etc.  (Kansas  Univ.  Quar.  vol.  ii.  p. 
83),  1S93.— Ibid.  vol.  Itl.  (1895),  p.  165.— University  Geol.  Surv.  Kansas,  vol.  IV.  Topeka,  1898. 
—  Waiiston,  S.  ir..  and  Oase,  E.  C,  Kansas  Mosasaurs  (Kansas  Univ.  Quar.  vol.  T.  p.  1),  1892. 


154 


REPTILIA 


CLASS  III 


maxillae  are  all  unpaired,  as  are  also  the  nasals,  vvhich  are  fused  with  the 
premaxillae.       The    supratemporal    vacuity    is    bounded    externally    by    the 

prosquamosal  and  postorbital,  which  form  a 
narrow  arcade.  The  squamosal  is  iiitercalated 
between  the  exocciptal  ( =  parocciptal,  Baur) 
and  the  prosquamosal,  and  sends  a  slender 
process  inwards  between  the  exoccipital  and 
proötic,  extending  nearly  as  far  as  the  brain 
cavity.  The  suture  between  the  pqstorbital 
and  postfrontal  is  often  obliterated.  Super- 
ciliary  plates  have  not  been  observed,  and  are 
often  functionally  replaced  by  the  horizontally 
expanded  prefrontals.  The  jugal  unites  with  a 
descending  process  of  the  postfrontal,  and  these 
two  bones  together  with  the  prefrontal  com- 
pletely  enclose  the  orbit.     There  is  a  complete 


Cli(laste!<  prnpythnn,  Cope.  Upper 
Cretuceous ;  Kansas.  Palatal  aspect 
of  skull,  paitly  lestored.  (bo,  Basi- 
occipital ;  niv,  Maxiila;  pl,  Palatine  ; 
pvix,  Premaxilla ;  pt,  Pterygoid  ;  ])t/, 
Ptjstorbito  -  frontal ;  opo,  '  öupiateni- 
poral  ;  i/iij,  Squamosal  ;  sph,  Basi- 
sphenoid  ;  vo,  Vonier.) 


Fig.  244. 


Flatecarpus  coryphaeus,  Cope.  Upper  Cretaceous  ;  Kansas.  Pos- 
terior aspect  of  skull,  1/4.  (bo,  Basioccipital ;  <■<>,  Exoccipital ;  y», 
Parietal;  pe,  Proötic;  pfo,  Postorbito  -  frontal  ;  pt,  Pterygoid;  7, 
Quadrate ;  so,  Supraoccipital  ;  sq,  Squamosal  ;  xt,  Stapes),  (after 
Williston.) 


parietal  arch  formed  by  a  slender  process  of  the  parietal  uniting  with  a 
process  of  the  squamosal. 

The  quadrate  (Figs.  245,  246)  is  relatively  large,  and  movably  articulated 
with  the  squamosal  and  prosquamosal.  Its  antero-superior  margin  is  dilated 
into  a  broad  thin  plate,  and  its  posterior  margin  is  notched  or  perforated  foi' 
the  auditory  meatus.  This  opening  is  either  partially  or  completely  enclosed 
posteriorly  by  the  stout  suprastapedial  process,  which  is  especially  character- 
istic  of  the  Mosasaur  quadrate.  On  the  concave  inner  side  of  the  quadrate, 
near  the  upper  part  of  the  meatal  notch,  is  a  small  pit  for  the  lodgment  of  the 
outer  end  of  the  stapes.  The  quadrate  exhibits  wide  Variation  in  form  and 
size  amongst  the  different  genera. 

The  transverse  bone,  or  ectopterygoid,  is  always  small,  and  joins  the 
pterygoid  and  jugal  only.  A  slender  columella,  or  epipterygoid,  is  present  in 
all  cases.  The  mandibular  rami  were  united  at  the  Symphysis  by  ligaments. 
Somewhat  back  of  the  middle  of  each  ramus,  between  the  angular  and  splenial, 
and  the  dentary  and  surangular,  there  is  a  movable  articulation  permitting  of 
a  wide  distension  of  the  jaws. 


ORDER  II 


SQUAMATA 


155 


A  Single  series  of  large  conical  teeth  occurs  in  both  upper  and  lower  jaws, 
those  of  the  pterygoid  being  inferior  to  the  rest  in  size.  The  crown  often 
exhibits  slight  anterior  and  posterior  carinae,  and  may  be  bevelled  into  several 
longitudinal  facettes  ;    and  the  enamelled    surface  may  be  either  smooth  or 


Fig.  245. 

Mosasaurus  camperi,  v.  Mej'er.  A,  Guter;  and  /.',  Inner 
aspect,  1/4.  (al,  Suprastapedial  process ;  k,  Stapedial  pit ; 
l,  Meatus ;  m,  Suijerior  iiiargin  ;  n,  Inferior  niargin),  (alter 
Owen.) 


CUduates  propython,  Cope. 
Quadrate,  inner  aspect,  %. 
(Lettering  as  in  Fig.  245), 
(after  Cope). 


delicately  striated.  All  the  teeth  are  fixed  by  tumid  osseous  bases  in  shallow 
pits  of  the  supporting  bone.  Successional  teeth  arise  alongside  the  functional 
ones,  and  gradually  displace  them  by  pressure  against  the  crown  on  the  inner 
side. 

The  pectoral  arch  (Fig.  247)  exhibits  a  rather  Jarge  and  flattened  coracoid, 
the  articular   border  of   which    is   thickened   and    divided    into   two   facettes 


Clulastes  ixlox,  Marsh. 


Pectoral  arcli,  dorsal  aspect,  V.3-     (^S  Coracoid  ;  h,  Hunieiu> 
Radius  ;  sc,  Scapula  ;  «,  Ulna  ;  I-V,  Digits),  (after  Marsh). 


uic,  Metacarpus ; 


meeting  at  an  obtuse  angle,  while  the  thin  inner  edge  is  rounded,  and  often 
incised  by  a  deep  notch  or  emargination.  There  is  a  small  coracoid  foramen 
situated  toward  the  articular  border.  Posteriorly  the  coracoids  meet  the 
sternum,  which  was  probably  never  ossified,  but  composed  of  calcified  cartilage, 
quite  like  the  sternal  ribs.  The  coracoids  are  separated  from  each  other  by  a 
broad  epicoracoidal  expanse  of  cartilage.  The  scapula  is  placed  as  in  Rhyn- 
chocephalians ;  a  slender  interclavicle  (episternum)  is  present,  but  clavicles  are 


I» 


156 


EEPTILIA 


CLASS  III 


wanting.  The  humerus  is  short  and  stout,  its  articular  ends  expanded,  and 
the  distal  end  with  two  facettes  for  the  bones  of  the  second  segment.  Of  the 
latter  the  radius  is  distally  expanded.  The  carpals  vary  in  number  from 
seven  (arranged  in  two  rows)  in  CUdastes  and  Mosasaurus,  to  one  or  two 
rudimentary  ossicles  in  Tylosaurus.  There  are  five  metacarpals,  differing  in 
shape  amongst  the  various  genera,  and  supporting  a  variable  number  of 
phalanges ;  these  last  being  comparatively  few  in  CUdastes  and  Mosasaurus, 
and  as  many  as  eleven  or  twelve  in  the  paddles  of  Tylosaurus.  None  of  the 
digits  are  clawed. 

The  pelvic  arch  (Fig.  248)  is  more  weakly  developed  than  the  pectoral. 
The  ilium  is  a  slender  rod-shaped  bone,  its  superior  end  free  or  loosely 
attached  to  the  single  vertebra  which  functions  as  a  sacrum.  The  pubes 
probably  do  not  meet  in  a  ventral  Symphysis,  but  the  ischia  are  joined  along 


Platecarpus  simus,    iarsli  sp 
(/,  Feiuur  ;  /',  Fibula  ;  ü,  Iliuvn  ;  is,  Tscliiu 


Upper  Cretaceous  ;  Kansas.     Pelvic  arch  and  paddles,  i/jo. 

mt,  Metatarsus  ;  ph,  Pubis  ;  t,  Tibia  ;  I-V,  Digits),  (alter  Marsh). 


an  extensive  articular  surface.  The  bones  of  the  bind  limb  resemble  those  of 
the  fore,  but  are  more  slender,  and  somewhat  smaller.  There  are  probably 
never  more  than  three  tarsals,  and  sometimes  only  one.  Four  or  five  digits 
are  developed,  with  a  variable  number  of  phalanges.  As  a  rule  the  posterior 
paddles  are  smaller  than  the  anterior  pair. 

The  limbs  of  Pythonomorphs  and  Cetaceans  furnish  an  excellent  illustra- 
tion  of  the  influenae  of  environment  in  producing  analogous  structures  among 
widely  divergent  groups.  As  a  result  of  their  complete  adaptation  for  an 
aquatic  existence,  Mosasaurs  and  whales  have  developed  a  very  similar  form 
of  body.  Most  of  the  Pythonomorphs  were  of  large  size,  and  enjoyed  a  wide 
distribution,  their  remains  being  known  from  the  Upper  Cretaceous  of  Europe, 
North  and  South  America,  and  New  Zealand. 

The  Pythonomorphs  were  covered  externally  with  scales  very  similar  in 
size  and  structure  to  those  of  Varanus.  These  scales  have  been  found 
impressed  upon  the  bones  of  the  skull,  indicating  the  absence  of  corneous 
plates.  There  were  no  dermal  ossifications  of  any  kind.  Small  or  medium- 
sized  fishes  have  been  observed  in  the  fossilised  stomach  contents  in  several 
instances. 

The  earliest  discovered  cranium,  found  in  the  Maestricht  Chalk  in  1780, 
was  mistaken  for  that  of  a  Cetacean  or  Crocodilian  until  Cuvier  demonstrated 
its  remarkable  similarity  to  the  skull  of  Varanus.  Owen  united  Mosasaurs 
with  lizards  under  the  designation  of  Lacertilia  natantia.  The  name  Ff/fhono- 
morpha  was  proposed  in  1869  by  Cope,  who  regarded  the  group  as  inter- 
mediate  between  snakes  and  lizards.     It  is  argued  by  Dollo  and  Willistoii. 


ORDER  II  SQUAMATA  157 

however,  that  Pythonomorphs  could  not  have  been  ancestral  to  the  modern 
Squamata,  since  it  is  impossible  to  suppose  that  forms  which  became  so  highly 
specialised  and  completely  adapted  to  an  aquatic  existence,  should  have  ever 
again  reverted  to  a  generalised  condition,  and  reassumed  terrestrial  habits. 
Pythonomorphs  arose  undoubtedly  from  land  animals,  and  may  have  sprung 
from  Dolichosaurian  ancestors ;  but  they  appear  to  have  passed  completely 
out  of  existence  near  the  end  of  the  Cretaceous,  without  leaving  any  progeny. 
Their  extreme  differentiation  is  attested  by  the  loss  of  a  sacrum,  multiplica- 
tion  of  phalanges,  degeneration  of  the  hind  paddles,  development  of  a  man- 
dibular Joint,  and  other  characters,  of  which  no  heritage  remains  amongst 
modern  Squamata. 

Family  1.     Mosasauridae. 

This  family,  with  the  characters  of  the  sub-order,  comprises  three  rather 
divergent  groups,  which  are  considered  of  sub-family  value.  Restricted  to  the 
Upper  Cretaceous. 

Siib-Family  A.     Tylosaurinae.     Williston. 

Hind  limb  fundionally  pentadactyle.  Trunk  shmi,  tau  proportionately  long. 
Fremaxillae  produced  into  a  long  rostrum  in  advance  of  the  teeth  ;  quadrate  with 
Short  suprastapedial  process.  Carpus  and  tarsus  almost  wholly  unossified;  phalanges 
numerous.      Vertehrae  without,  or  with  very  rudimentary  zygosphenes. 

Tylosaurus,  Marsh  {Liodon,  Cope  ;  Macrosaurus,  Owen  ;  Rhinosaurus,  Marsh). 
Skull  0*7  to  over  1  m.  long.  Superior  surface  of  parietal  smooth  and  produced 
to  the  posterior  margin  in  the  median  line,  with  nearly  parallel  sides  ;  foramen 
at  its  anterior  margin.  Postfrontal  and  prefrontal  meeting  on  the  superior 
border  of  the  orbit ;  quadrate  stout,  with  very  short  suprastapedial  process ; 
maxilla  with  about  thirteen  large  teeth.  One  or  two  carpal  and  tarsal  bones 
present,  not  articulating  with  adjacent  elements.  Coracoid  not  emarginate ; 
limbs  about  equally  developed ;  phalanges  numerous  ;  fifth  digit  elongate. 
Haemapophyses  loosely  articulated ;  no  zygosphenes.  Niobrara  Group ; 
Kansas,  New  Mexico,  and  Texas.     T.  proriger,  T.  dyspelor,  Cope. 

Hainosaurus,  DoWo.  Skull  upwards  of  1*5  m.  long.  Frontal  broad ;  pre- 
frontal and  postfrontal  meeting  over  the  orbit ;  teeth  of  unequal  size.  Carpals 
reduced  in  number ;  phalanges  fewer  than  in  Tylosaurus,  and  paddles  relatively 
larger.  Haemapophyses  loosely  articulated  ;  cervicals  with  small  zygosphenes. 
Upper  Cretaceous ;  Belgium. 

Sub-Family  B.     Platecarpinae.     Williston. 

Hind  limb  fundionally  pentadactyle.  Trunk  short,  tau  proportionately  lang. 
Premaxillae  short,  very  obtuse,  and  projeding  but  little  in  front  of  the  teeth.  Quadrate 
large,  with  a  long  suprastapedial  process.  Carpus  and  tarsus  imperfedly  ossified. 
Vertebrae  with  rudimentary  {or  fiindional?)  zygosphenes.  Interdavide  probably 
present  in  all  forms. 

Platecarpus,  Cope  {Lestotaurus,  Marsh;  1  Holcodus,  Gibbes),  (Figs.  248-250). 
Total  length  about  5  m.,  of  which  the  skull  forms  one-eighth.  Superior  sur- 
face of  parietal  small,  triangulär,  not  reaching  beyond  the  middle  of  the  bone ; 
large  oval   foramen   at   its   anterior   border.      External   nares   much   dilated 


158 


REPTILIA 


CLASS  III 


S    K 


anteriorly.  Quadrate  large,  with  prominent  supra- 
stapedial  process  extending  below  the  middle  of  the 
bone ;  opening  for  the  auditory  meatus  large,  not 
entirely  enclosed.  Teeth  slender  and  recurved, 
facetted  on  the  outer  side,  striate  on  the  inner; 
maxillae  with  about  twelve,  and  pterygoid  ten  to 
twelve  teeth.  Coracoid  deeply  emarginate  on  inner 
border.  Four  carpals  and  three  tarsals  present, 
closely  articulating.  Fifth  digit  shorter  than  the 
fourth,  and  divergent.  Chevron  bones  large,  loosely 
articulated.     Abundant  and  represented  by  numerous 


Flatecarpus  coryphaeiis,  Cope.    Upper  Cretaceoiis ;  Logan  County, 
Kansas.     Skull,  superior  aud  lateral  aspects,  1/7  (after  Merriaiii). 

species  in  the  Upper  Cretaceous  of  Kansas,  Colorado, 
Texas,  North  Dakota,  and  France. 

Holosaurus,  Marsh.  Very  similar  to  the  preceding, 
except  that  the  coracoids  are  not  emarginate  ;  there 
are  no  zygosphenes  in  the  only  known  specimen. 
Kansas. 

Flioplatecarpiis,  Dollo  (Oterognathus,  Dollo).  Similar 
to  Flatecarpus,  but  with  smaller  chevron  bones.  Quad- 
rate with  large  meatal  opening.  Mandible  slender, 
coronoid  rudimentary.  Teeth  long  and  slender, 
facetted,  and  striate.  Danian  of  Maestricht,  and 
Upper  Senonian  of  Belgium. 

Prognathosaurus,  Dollo.  Skull  about  0-6  m.  long. 
Pterygoids  nearly  as  large  as  the  maxillae,  and  with 
very  powerful  teeth.  The  large  suprastapedial  process 
of  the  quadrate  coössifies  with  the  infrastapedial 
process,  and  encloses  an  oval  foramen.     A  wide  canal 


ORDER  II 


SQUAMATA 


159 


present  in  lower  pait  of  the  basioccipital.  Mandible  strong,  upper  edge 
concave,  coronoid  process  prominent.  Coracoid  non-emarginate ;  chevrons 
loosely  articulated.      Brown  Phosphate  Chalk  ;  Belgium. 

Brachysaurus,  Williston.  Frontal  large  and  broad  ;  no  median  basioccipital 
canal.  Suprastapedial  process  of  quadrate  coössified  with  the  infrastapedial. 
No  zy gosphenes ;  chevrons  fused  with  their  centra.  Possibly  identical  with 
preceding  genus.     Ft.  Pierre  Cretaceous  ;  South  Dakota. 

Phosphorosaurus,  Dollo.  Imperfectly  known.  Frontal  very  narrow,  with 
nearly  parallel  sides,  and  taking  part  in  the  superior  border  of  the  orbit. 
Parietal  small ;  its  exposed  surface  triangulär,  and  with  very  large  foramen 
at  its  front  margin.  Suprastapedial  process  much  elongated  and  united  with 
the  infrastapedial,  enclosing  an  elongated  meatal  opening.  Tympanic  cavity 
extended  and  shallow.      Upper  Cretaceous  ;  Belgium. 

Taniwhasau7-us,  Hector.  Allied  to  Platecarpus.  Cretaceous ;  New 
Zealand. 


Siib-Family  C.     Mosasaurixae.     Willistoii. 

Hind  limh  tetradadyle.  Trunk  elongated,  tau  much  dilated  distally.  Pre- 
maxillae  forming  a  short  and  oUusely  conical  rostrum.  Prefrontals  more  m'  less 
dilated  inta  a  horizontal  plate  posteriorly.  Quadrate  small,  with  moderate-sized 
suprastapedial  process.  Coronoid  large,  articulating  with  the  splenial  on  the  inner 
side.  Humerus  with  strong  radial  process  at  distal  end.  Carpus  and  tarsus  com- 
pletely  ossißed ;  not  more  than  six  phalanges  in  any  of  the  digits.  Zygosphenes  rudi- 
mentary  or  functional,  chevrons  fused  with  their  cerdra. 

ülidastes,  Cope  {E desto saurus,  Marsh),  (Figs.  242,  4,  6,  7,-251).  Skull  0-4 
to  0*7  m.  long  ;  slender, 
tapering,  depressed. 
Frontal  not  emarginate 
posteriorly  in  the 
median  line.  Parietal 
foramen  entirely  within 
the  parietal  plate. 
Teeth  facetted  on  outer 
side,  and  smooth  on  the 
inner  or  on  both  faces. 
Dentary  with  about 
seventeen  teeth,  maxilla 
fifteen,  pterygoid 
twelve  to  fifteen. 
Zygosphenes  func- 
tional ;  chevrons  long. 
Neural  spines  elevated 

in   posterior  half   of   the  tail,  suggesting   presence   of  a   caudal   fin. 
Cretaceous ;  Kansas,  Alabama,  and  New  Jersey. 

Mosasaurus,  Conyb.  (Leiodon,  Owen;  Pterycollasaurus,  Dollo),  (Figs.  243, 
252).  Skull  attaining  a  length  of  1-2  m.,  and  total  length  of  about  12  m. 
Distinguished  from  Clidastes  chiefly  by  absence  of  a  zygosphene-zygantrum 
arrangement.  There  are  more  than  130  vertebrae  in  the  column,  of  which 
46  are  precaudal.     The  massive  upper  jaws  are  armed  with  about  fourteen 


Fig.  -251. 

Clidastes  propython,  Cope.     Upper  Cretaceous  ;  Uniontowii,  Alabama. 
Skull,  superior  and  lateral  aspects,  1/5  (after  Cope). 


Upper 


160  KEPTILIA  CLASSiii 

powerful  teeth  on  either  side,  and  the  pterygoids  support  about  eight  smaller 


Mosasaiiriui  camperi,  v.  Meyer.     Upper  Cretaceous  ;  Maestricht,  Holland. 
Skull,  lateral  aspect,  l/jo  (after  Dollo). 

teeth,  all  with  anterior  and  posterior  carinae.      Upper  Cretaceous 
Belgium,  France,  Northern  Germany,  and  the  United  States. 


Holland, 


[The  text  for  the  preceding  chapter  on  Pythonomorpha  has  been  revised  and  modified  in 
accordance  with  the  latest  researches  by  Dr.  S.  W.  Williston,  Professor  of  Geolog}^  and 
Palaeontology  in  the  University  of  Kansas,  at  Lawrence. — Editor.] 


Sub-Order  3.     LACERTILIA.     Saurii.     Lizards.i 

Scaly,  long-tailed  reptiles,  with  elongated  and  sometimes  serpeiitiform  hody. 
Superior  temporal  arcade  often  wanting,  and  quadrate  loosely  attached  to  the  cranium. 
Golumella  rod-like  or  rudimentary ;  alisphenoid  and  orbitosphenoid  not  ossified. 
Mandibular  rami  suturally  united  at  Symphysis;  teeth  acrodont  or  pleurodont. 
Sternum  usually,  and  limb  girdles  always  present,  but  one  or  both  pairs  of  appendages 
sometimes  wanting.     Limbs  ambulatory,  and  usually  provided  with  five  clawed  digits. 

The  majority  of  lizards  possess  a  dermal  covering  of  corneous  or  in  some 
cases  of  osseous  scales,  scutes,  or  spines,  extending  over  the  head  and  whole  of 
the  body.  The  vertebral  column  consists  of  numerous  procoelous  vertebrae 
(amphicoelous  only  among  the  Geckonidae  and  Uropellidae),  in  which  the  neural 
arches  are  thoroughly  coössified  with  their  centra.  There  are  seldom  more 
than  nine  cervicals,  and  the  atlas  is  composed  of  two  dorsal  pieces,  either 
separate  or  united,  and  one  ventral  piece  in  the  form  of  a  free  hypapophysis 
or  intercentrum.  Both  the  cervical  and  dorsal  series  have  the  transverse  pro- 
cesses  weakly  developed,  so  that  the  ribs  appear  attached  by  a  short  tubercle. 
All  of  the  ribs  are  single-headed.  They  are  wanting  on  the  anterior  cervicals, 
some  of  the  lumbar,  and  all  of  the  caudal  vertebrae.  The  sacrum  is  composed 
of  two  vertebrae.  Stout  transverse  processes  and  chevron  bones  are  borne  by 
the  caudals. 

A  sternum  is  present,  although  sometimes  rudimentary,  in  all  lizards 
except  Amphisbaena ;  it  usually  occurs  as  a  large  rhombic  or  shield-shaped 
bone,  sometimes  pierced  by  two  foramina.     The  ventral  portion  of  the  anterior 

^  Literature  : 

Cope,  E.  D.,  The  Vertebrata  of  the  Tertiary  Formations  of  the  West  (Rept.  N.S.  Geol.  Surv. 
Territ.  vol.  III.),  1883. — Marsh,  0.  C,  On  Glyptosaurus,  Tinosanrus,  etc.  (Amer.  Jonrn.  Sei.  [3], 
vol.  I.  p.  456),  1871  ;  and  iUd.  vol.  IV.  (1872),  p.  298. — Meyer,  H.  ton,  Lacerten  aus  der 
Braunkohle  des  Siebengebirges  (Palaeontogr.  vol.  VII.  p.  74),  1860. — Parker,  W.  K.,  On  the 
structure  and  development  of  the  skull  in  the  Lacertilia  (Phil.  Trans,  vol.  CLXX.),  1880. 


ORDER  II 


SQUAMATA 


161 


dorsal  ribs  which  join  the  sternum  are  sometimes  cartilaginous,  and  in  other 
cases  bony. 

The  skull  (Fig.  253)  is  distinguished  from  that  of  Rhynchocephalians 
chiefly  by  its  large  free  quadrate,  a  delicate  rod-like  columella,  and  the  con- 
stant  absence  of  a  lower  and  occasional  absence  of  an  upper  temporal  arcade. 


Qu.] 


Fig.  253. 

Monitor  nüoticus,  Hassl.  Recent ;  Egypt.  Skull,  lateral  aspect,  i/i-  (eol,  Columella  or  epipterygoid  ;  cm, 
Exoccipital ;  fr,  Frontal ;  ju,  Jugal ;  la,  Lachrymal ;  mx,  Maxilla  ;  N,  Narial  opening  ;  na,  Nasal ;  pa,  Parietal ; 
pl,  Palatine  ;  pmx,  Premaxilla  ;  prf,  Prefrontal ;  pro,  Proötic  ;  pt,  Pterygoid  ;  ptf,  Postfrontal ;  qu,  Quadrate  ; 
(luj,  Quadrato-jugal ;  S,  Supratemporal  vacuity  ;  so,  Supraoccipital ;  sq,  Squamosal ;  t,  Transverse  bone  or  ecto- 
pterygoid  ;  y,  Öuperciliary),  (after  Cuvier). 

The  vomer  is  unpaired,  and  not  in  contact  with  the  pterygoids ;  and  the 
latter,  together  with  the  palatines,  form  a  fiat  thin  palate  pierced  by  large 
vacuities.  A  transverse  bone  (ectopterygoid)  occurs  between  the  maxillae 
and  pterygoids.  The  external  nares  are  separate,  and  commonly  placed  near 
the  Orbits.  The  opisthotic  is  fused  with  the  exoccipital,  forming  the  so-called 
parotic  process  of  the  posterior  temporal  region.  The  distal  end  of  this 
process  serves  with  the  posterior  ends  of  the  squamosal  and  prosquamosal  as 
a  buttress  to  which  the  movable  quadrate  is  attached.     The  squamosal  itself 


Fig.  254. 
Iguana  tuberculata,  Laur.     Recent ;  West  Tndies,     Inner  aspect  of  right  ramus  of  mandible,  showing  pleuro- 
dont  teeth.    (ang,  Angular  ;  art,  Articular ;  d,  Dentary  ;  k,  Coronoid  ;  op,  Splenial ;  s.ang,  Surangular),  (after 
Cuvier). 

is  of  small  size  and  situated  between  the  outer  angle  of  the  parietal  and 
distal  end  of  the  prosquamosal.  The  postorbito- frontal  unites  with  the 
forward  end  of  the  prosquamosal  to  form  the  lower  border  of  the  superior 
temporal  fossa,  and  also  unites  with  the  jugal  to  form  with  this  bone  the 
posterior  border  of  the  orbit.  In  lizards  the  jugal  is  never  in  direct  connec- 
tion  with  the  quadrate.  A  parietal  foramen  occurs,  and  the  parietal  is 
frequently  unpaired. 

The  mandibular  rami  (Fig.  254)  are  suturally  united  at  the  Symphysis ; 
they  exhibit  the  same  structure  as  in  Pythonomorphs,  except  that  there  is  no 
movable  articulation  behind  the  middle  of  each  ramus.      Teeth  are  always 
VOL.  II  M 


162  KEPTILIA  class  iii 

present  in  upper  and  lower  jaws,  and  occur  rarely  on  the  palatines,  pterygoids, 
and  vomer.  They  are  either  acutely  or  obtusely  conical,  chisel-  or  arrowhead- 
shaped,  serrated  or  carinated  on  the  anterior  and  posterior  edges,  or  in  some 
cases  their  form  may  be  hemispherical.  Their  bases  are  completely  fused 
with  the  supporting  bone,  and  their  arrangement  is  either  acrodont  or  pleuro- 
dont.  Successional  teeth  are  developed  on  the  inner  side  of  the  functional 
ones,  and  gradually  displace  them. 

As  a  rule  two  pairs  of  limbs  provided  with  five  clawed  digits  are  present, 
although  the  hinder  pair  may  be  rudimentary,  and  in  some  cases  both  pairs 
are  wanting.  The  limb  girdles  persist,  however,  even  among  apodal  forms, 
but  the  pelvic  arch  may  become  reduced.  The  coracoid  is  relatively  large, 
and  develops  an  anterior  process,  or  precoracoid.  The  scapula  also  consists 
of  two  portions,  of  which  the  distal  (suprascapula)  is  the  larger  and  usually 
remains  cartilaginous.  The  scapula  proper  is  in  some  cases  bifid  at  its  distal 
extremity.  The  rod-shaped  clavicle  connects  the  anterior  border  of  the 
scapula  with  the  T-shaped  or  cruciform  interclavicle,  which  is  situated  in 
front  of  the  sternum.  The  bones  of  the  fore-limb  resemble  those  of  Ehyn- 
chocephalians,  except  that  the  humerus  never  displays  distal  foramina. 
There  are  eight  small  carpals  arranged  in  two  rows,  and  the  usual  phalangeal 
formula  is  2,  3,  4,  5,  3. 

Where  the  bind  limb  is  normally  developed,  the  ilia  are  movably  attached 
to  the  cartilaginous  ends  of  the  sacral  ribs.  Pubes  and  ischia  meet  in  a 
ventral  Symphysis,  and  the  anterior  border  of  the  former  frequently  develops 
a  strongly  curved  process.  The  femur  generally  exceeds  the  humerus  in 
length,  and  the  bones  of  the  crus  remain  separate.  The  proximal  tarsals 
consist  of  a  large  tibiale  (astragalus)  and  fibulare  (calcaneum) ;  there  are 
often  but  two  free  tarsals  present  in  the  distal  row  (Nos.  III.  and  IV.),  the 
remainder  being  fused  with  the  metatarsals.  The  phalangeal  formula  of  the 
pes  is  usually  2,  3,  4,  5,  4. 

Lizards  of  the  present  day  are  restricted  almost  exclusively  to  the  tropical 
afld  temperate  zones,  and  according  to  HofFmann  they  comprise  434  genera 
and  1925  species,'  In  comparison  to  these,  the  number  of  known  fossil  forms 
is  very  insignificant.  The  oldest  remains  commonly  associated  with  lizards 
are  the  fragmentary  jaws  and  procoelous  vertebrae  from  the  English  Pur- 
beckian,  known  as  Macellodus  brodiei,  but  these  are  too  imperfect  for  accurate 
determination.  Most  of  the  detached  vertebrae  and  other  fragments  of 
Cretaceous  age  which  have  been  referred  to  Lacertilians  or  Ophidians  are 
probably  Dolichosaurian. 

Even  the  known  Tertiary  fossils  are  very  fragmentary,  and  belong  for  the 
most  part  to  existing  families.  From  the  Lower  Eocene  of  Wyoming  repre- 
sentatives  are  known  of  the  Varanidae  (Tinosaurus),  Anguidae  {Glyptosauru^, 
Saniva,  Xestops),  Iguanidae  (Iguanavus),  and  Chamaeleonidae.  Iguana  itself, 
now  restricted  to  the  western  heraisphere,  occurs  in  the  European  Tertiary. 
Fragmentary  remains  of  a  number  of  other  recent  genera  are  found  in  the 
Eocene  (or  Oligocene)  Phosphorites  of  Quercy,  and  Gypsum  Beds  of  Apt,  in 
France,  among  which  may  be  mentioned  the  following  : — Proiguana  (Fig.  255), 
Plestiodon  (Fig.  256),  Palaeovaramis  (Fig.  257),  Agama,  Diploglossus,  and 
Lacerta. 

The  Miocene  also  yields  a  number  of  Lacertilian  fragments  identifiable 
with   recent   genera,   the  principal    localities   being   Auvergne,    France ;    the 


ORDER  II 


SQUAMATA 


163 


lignites  of  Eott,  near  Bonn ;  and  the  freshwater  strata  of  Steinheim,  Haslach, 
Günzburg,    Sansan,   and   Colorado.      The    most    gigantic   of   all   lizards  are 


liww*^^ 


P'iG.  255. 

(■?)  Froiguana,  sp.  Plios- 
l>liorite  of  Quercy.  Inner  aiul 
outer  aspect  of  dentary,  i/j. 


Fig.  256. 

Plestiodon  caclurcensis, 
Filhol.  Phosphorite  of 
Quercy.  Inner  aspect  of 
dentary,  i/]. 


Fio.  257. 

Folaeovaranus  cayluxi,  Filhol.     Phos- 
phorite   of    Quercy.      Maxillary    frag- 

inent,  i/j. 


Megalania  and  Notiosaurus,  from  the  Pleistocene  river  deposits  of  Queensland. 
The  form  er  is  estimated  to  have  been  about  10  m.  in  length,  and  belongs  to 
the  Yaranidae. 

Sub-Order4.     OPHIDIA.     Snakes.i 

Body  serpentiform,  without  limhs,  covered  with  corrteous  scales.  Vertehrae 
procoelous,  with  zygosphene-zygantrum  articulation,  and  the  anterior  centra  with 
strong  simple  hypapophyses.  Both  upper  and  lower  temporal  arcades,  columella, 
sacrum,  sternum,  pedoral  arch,  abdominal  ribs  and  haemapophyses  are  wanting. 
Parietal  nnpaired,  without  foramen,  the  sides  extended  downward  and  fxised 
with  the  proötic,  alisphenoid,  and  orbitosphenoid.  Anterior  portion  of  brain  case 
completely  ossified.  Quadrate  and  pterygoid  movably  attached  to  skull  by  ligamenf. 
Maxillae  and  palatines  usually  freely  movable,  always  displaceable.  Premaxillae 
much  reduced  ;  mandibular  Symphysis  ligamentous. 

Snakes  are  chiefl37-  conspicuous  for  the  absence  of  limbs.  The  body  is 
greatly  elongated,  and  the  number  of  vertebrae  very  considerable,  sometimes 
exceeding  400.  The  centra  are  concave  in  front  and 
convex  behind,  the  connection  being  by  free  ball-and- 
socket  joints ;  and  their  articulation  is  further 
strengthened  by  zygapophyses  and  a  zygosphene- 
zygantrum  arrangement.  The  neural  arches  are 
thoroughly  coössified  with  their  centra.  Simple 
hypapophyses  are  developed  by  the  anterior  ver- 
tebrae as  far  as  sometimes  the  thirtieth,  and  the 
transverse  processes  are  short  and  tumid  (Fig.  258). 
Ribs  are  almost  always  present  in  the  trunk  region, 
beginning  with  the  third  vertebra ;  and  being  freely 
articulated,  are  able  to  assist  in  propelling  the  body.   R 

They  are  long,  curved,  and  frequently  hollow ;  in  the  ep^AxiVr^iJ/irHypapophys^s 
caudal  region  they  are   replaced   by  elongate   trans-  jXi.r  ""'""'  '''"^'  ^''''' 
verse  processes.     Haemapophyses  are  wanting  among 

snakes,  and  in  their  stead  occur  stout  descending  branches  of  the  transverse 
processes  (Fig.  259). 

^  Literature  : 

Cope,  E.  D.,  The  Vertebrata  of  the  Tertiary  Formatious  of  the  West  (Rept.  U.  S.  Geol.  Surv. 
Territ.  vol.  III.),  1883.— Filkol,  II.,  Ann.  Sei.  Geol.  vol.  VIII.  (1887),  p.  270.— Fischer,  G.,  De 
ser})entibus  quibiisdam  fossilibus  dissertatio.  Bonn,  I8b7.— Meyer,  IL  von,  Coluber  atavus  aus 
dem  Siebengebirge  (Palaeontogr.  vol.  VII.),  I860.—Rochebrune,  A.  F.  de,  Revision  des  Ophidiens 
fossiles  (Nouv.  Arch.  Musee  d'Hist.  Nat.  Paris  [2],  vol.  III.),  ISSO.—Rvemer,  i^.,  Ueber  Python 
euboeicus  (Zeitschr.  deutsch,  geol.  Ges.  vol.  XXII.),  1870. 


Python    bivittatui 
ecent;    Sumatra, 
cervical  vertebrae,  i/j.    (a,  Atlas ; 


Sehn. 
Anterior 


164 


KEPTILIA 


CLASS  II 


Fig.  259. 


The  serpent  cranium  (Fig.  260)  differs  from  that  of  lizards  in  the  constant 
absence  of  both  temporal  arcades ;  complete  ossification  of  the  anterior  part 
of  the  brain  case  ;  reduction  of  the  premaxillae  ;  absence 
of  a  columella  ;  strong  development  of  the  ectopterygoid, 
which  joins  the  maxillary  and  palato-pterygoid  arches ; 
and  movable  connection  between  not  only  all  of  the  last- 
named  bones,  but  between  the  squamosal  and  occipital 
region,  and  between  the  rami  of  the  lower  jaw.  The 
brain  cavity  is  very  long,  and  its  lateral  walls  as  far  as 
the  middle  portion  are  formed  by  descending  processes 
Python  bivittatus,  Caudai  of  the  parietal  and  frontal.     The  exoccipital  and  opis- 

vertebra,    posterior    aspect.     ,^      ,'  r         ^  i    .-i  ^^^       •         r.  i.        j         j 

c,  ceiitrum ;  d,  d',  Trans-  thotic  are  lused,  and  the  maxilia  IS  oiten  mucn  reduced. 
TnTbrSI'.a^'yylSS^^    ^^1  the  Cranial  bones  are  dense  and  ivory-like,  and  united 
by  smooth  sutures. 

Acicular,  recurved,  acrodont  teeth  are  usually  present  on  the  maxillae, 
premaxillae  pterygoids,  palatines,  and  dentary  bones.  Occasionally  they  are 
wanting  on  the  palatines  (üropel- 

tidae),  and  often  also  on  the  rudi-  p^p    ^    ^f    P     Ocs 

mentary     premaxillae.        In     the  "'' 

venoüious  snakes  some  of  the 
maxillary  teeth  are  hollow  and 
traversed  by  a  canal  or  groove 
ending  in  a  slit-like  opening  at  the 
end  of  the  tooth.  The  canal  is 
connected  with  the  duct  of  a 
poison  gland,  and  through  it  the 
secretion  of  the  latter  is  forced 
when  the  animal  strikes.  Some 
of  the  non-poisonous  snakes  also 
have  grooved  teeth  immovably 
fixed  to  the  maxillae. 

Locomotion  among  snakes  is 
accomplished  by  the  lateral  move- 
ments  of  the  vertebral  column, 
assisted  by  the  ribs,  the  latter 
being  alternately  pushed  forward 
and  the  dermal  sciites  drawn  after 
them. 

The  Ophidia  are  distributed  principally  in  the  warmer  regions,  only  the 
smaller  forms  extending  into  the  northern  temperate  zone.  By  far  the 
greater  number  are  terrestrial,  although  some  are  amphibious,  and  a  few  are 
exclusively  marine.  About  400  recent  genera  and  nearly  1800  species  are 
known,  as  compared  with  only  about  35  fossil  forms,  the  majority  of  which 
are  very  imperfect.  Most  of  the  detached  vertebrae  of  Cretaceous  age 
originally  regarded  as  Ophidian  are  doubtless  Dolichosaurian,  and  the  known 
Tertiary  species  are  scarcely  to  be  distinguished  from  those  now  living. 
Tolerably  complete  skeletons  occur  rarely  in  the  freshwater  Miocene  of 
Oeningen  and  Euboea,  as  well  as  in  the  lignites  near  Bonn,  and  belong  chiefly 
to  the  non-poisonous  varieties. 

Typically   Ophidian  vertebrae   (Palaeophis)   from    the   Lower    Eocene    of 


Fig.  260. 

Crotalus  horridus,  Linn.  Recent ;  South  America,  (art, 
Articular ;  bs,  Basisphenoid  ;  d,  Dentary  ;  et,  Etliiiioid  ;  /, 
Frontal ;  mx,  Maxiila ;  n,  Nasal ;  ocb,  Basioccipital ;  (x-l, 
Exoccipital ;  ocs,  Supraoccipital ;  p,  Parietal ;  pf.  Post- 
frontal ;  pl,  Palatine ;  pmx,  Premaxilla ;  pr,  Proötic ;  prf, 
Prefrontal ;  pt,  Pterygoid  ;  qu,  Quadrate  ;  sq,  Squamosal ; 
tr,  Transverse  or  ectopterygoid),  (after  Claus). 


ORDER  III  ICHTHYOSAURIA  165 

Sheppey  and  Bracklesham,  England,  and  Cuise  la  Mothe  France,  are  ascribed 
to  marine  Pythonidae  which  may  have  attained  a  length  of  6  m.  A  vicarious 
genus,  Titanophis,  occurs  in  the  Eocene  of  New  Jersey,  and  several  genera 
(Helagiis,  Cope ;  Boavus,  Lithophis,  and  Limnophis,  Marsh)  have  been  described 
from  the  Eocene  of  Wyoming  and  New  Mexico.  Among  the  Upper  Eocene 
(or  Oligocene)  forms  of  France,  Switzerland,  and  England  may  be  mentioned 
Palaeopython  (Fig.  261)  and  Scytalophis,  Eochebrune,  and  Paleryx,  Owen.- 


c 

Fig.  2Ö1. 


Palaeopytlwn  cadurceiisis,  Filhol  sp.  Phosphorite  of  Quercy,  France.  A,  Anterior.  B,  Lateral.  C.  Inferior. 
D,  Posterior  aspect  of  vertebra,  i/j.  (c,  Centrum ;  d,  Transverse  process  with  costal  tubercle  ;  sp,  Neural  spine  ; 
z,  Zyapophysis ;  za,  Zygantrum  ;  zsp,  Zygosphene.) 

One  of  the  best  preserved  Miocene  serpents  is  Heteropython  euboeicus, 
Eoemer,  from  Kumi,  on  the  island  of  Euboea.  Eepresentatives  of  the 
Colubridae  (Maphis,  Aldr. ;  Coluher,  Linn.),  and  Erycidae  (Scaphophis,  Eoch.) 
have  been  described  from  the  freshwater  Miocene  of  Oeningen,  Steinheim, 
Günzburg,  Haeder,  Weisenau,  Ulm,  Sansan,  Touraine,  and  other  localities,  as 
well  as  from  the  lignites  of  Eott,  near  Bonn.  A  number  of  Erycidae  and 
Crotalidae  are  also  known  from  the  Miocene  of  Colorado  and  Oregon.  All 
known  Pleistocene  remains  are  identifiable  with  existing  genera. 

Order  3.     ICHTHYOSAURIA.     {Ichthyopterygia}) 

Primitive  marine  reptiles  withfish-like  body,  long  head  and  tail,  and  no  distinct  neck. 
Investi7ig  bones  of  temporal  region  contracting  into  a  single  broad  arcade ;  quadrate 
fixed.  Rostrum  long  and  tapering  ;  orbits  large,  laterally  placed,  with  sclerotic  ring. 
External  nares  separate,  slightly  in  advance  of  orbits.  Parietal  foramen  and  supra- 
temporal vacuities  large.  Teeth  acutely  conical,  inserted  in  a  continuous  groove  on 
the  maxillae  and  elongated  premaxillae  and  mandibles,  but  sometimes  wanting.  Vomer 
edentulous.  Vertebrae  numerous,  very  short,  deeply  amphicoelous.  Ribs  long, 
abdominal  ribs  present,  but  sternum  absent.  Pectoral  arch  consisting  of  coracoids, 
scapulae,  clavicles,  and  a  T-shaped  interclavicle.  Limbs  short,  paddle-shaped, 
sometimes  with  more  than  five  rows  of  phalanges,  and  a  layer  of  cartilage  around 
the  carpals,  tarsals,  and  phalanges.     No  dermal  armour. 

1  Baur,  G.,  On  the  raorpliology  and  origin  of  the  Ichthyopterygia  (Amer.  Nat.  vol.  XXI.  p.  837), 
1887  ;  also  Bericht,  20th  Versammlung  Oberrhein,  geol.  Vereins  (1887),  p.  20  ;  and  Anat.  Anz. 
vol.  X.  (1894),  p.  456. — Gope,  E.  D.,  On  the  cranium  of  Ichthyopterygia  (Proc.  Amer.  Assoc.  Adv. 
Sei.  vol.  XIX.  p.  197),  1870.— i^mös,  E.,  Die  Ichthyosaurier  der  süddeutschen  Trias  und  Jura 
Ablagerungen.  Tübingen,  1891. — Die  Hautbedecknng  von  Ichthyosaurus  (Württ  Jahresh.  p.  493), 
1894. — IIav:kms,  T.,  Memoirs  of  Ichthyosauri  and  Plesiosauri.  London,  1834.— J/orsÄ,  0.  C7.,  On 
Baptanodon,  etc.  (Amer.  Jouni.  Sei.  [3],  vol.  XVII.  p.  86),  1879  ;  also  ibid.  vol.  XIX.  (1880),  p.  491  ; 
and  vol.  L.  (1895),  p.  iQb.—Merriam,  J.  C,  Triassic  Ichthyopterygia  (Bull.  Californ.  Univ.  vol.  III. 
p.  63),  1902. — Owen,  R.,  Monograph  of  the  fossil  Reptilia  of  the  Liassic  Formations,  Part  III. 
(Palaeontogr.  Soc),  1881. — Monograph  of  the  fossil  Reptilia  of  the  Cretaceous  Formatious 
[ibid.),  1851. — Seeley,  H.  G.,  On  Ophthalmosaurus,  etc.  (Quar.  Journ.  Geol.  Soc.  vol.  XXX.  p. 
696),  1874.— On  the  skull  of  an  Ichthyosaurus  {ibid.  vol.  XXXVI.  p.  635),  1880.— Theodori,  C. 
Beschreibung  des  kolossalen  Ichthyosaurus  trigonodon  zu  Banz.     Munich,  1854. 


166 


EEPTILIA 


CLASS  III 


The  members  of  this  order  differ  conspicuously  from  all  living  reptiles, 
and  are  distinguished  chiefly  by  their  fish-like  form  of  body,  paddle-shaped 
limbs  with  numerous  oval  or  polygonal  phalanges,  large  head  with  elongated 
rostrum,  short  amphicoelous  vertebrae,  and  naked  integument.  The  snout 
resembles  that  of  a  dolphin,  the  teeth  are  crocodilian-like,  the  skull  and 
pectoral  girdle  suggest  those  of  lizards,  the  limbs  are  very  similar  to  the 
flippers  of  marine  mammals,  and  the  vertebrae  and  caudal  fin  are  decidedly 
fish-like.  As  regards  external  form,  limb-structure,  and  adaptation  to  a  marine 
existence,  they  depart  as  widely  from  other  reptiles  as  whales  do  from  land 
mammals,.  and  occiipy  as  isolated  a  position. 

The  absence  of  branchial  arches  and  shape  of  the  hyoid  bones  prove  that 
respiration  was  pulmonary  among  Ichthyosaurs ;  and  their  viviparous  habit  is 
demonstrated  by  a  number  of  well-preserved  skeletons  in  the  Lias  of  England 
and  Würtemberg,  which  exhibit  as  many  as  seven  embryonic  individuals  in 
the  abdominal  cavity.  Large  quantities  of  their  coprolites  occur  in  various 
localities,  and  contain  the  scales  and  bones  of  fishes,  and  fragments  of  cephalo- 
pods.  Ichthvosaurian  remains  are  found  exclusively  in  the  marine  deposits  of 
the  Mesozoic,  and  are  most  abundant  in  the  Lias.  Of  their  origin  nothing  is 
known,  although  it  is  certain  that  they  were  derived  from  land  animals.  The 
earlier  (Triassic)  forms  have  less  completely  paddle-shaped  extremities  than 
the  later.  Some  species  attain  a  length  of  9  m.,  and  the  smallest  are  only 
about  1  m.  long. 

The  skull  (Fig.  262)  is  conspicuous  for  its  elongated,  dolphin-like  rostrum 
and  enormous  orbits,  which  are  surrounded  by  a  ring  of  fifteen  to  nineteen  scler- 


Ichthyosaurus  acutirostris,  Owen.  Upper  Lias  ;  Curcy,  Calvados.  Skull,  supcrior  aiul  lateral  aspects,  V-i- 
A,  Orbit ;  ang,  Articular ;  d,  Dentary  ;  fr,  Frontal ;  j,  Jugal ;  Je,  Surangular  ;  md,  Mandible  ;  mx,  Maxilla  ;  A, 
External  narial  opening  ;  na,  Nasal ;  op,  Splenial ;  pa,  Parietal ;  2Wix,  Premaxilla  ;  por,  Postorbital ;  ptf,  Post- 
frontal  ;  Qvj,  Quadrato-jugal  ;  S,  Supratemporal  vacuity  ;  sei,  Sclerotic  plates  ;  si/,  S(iuainosal  ;  st,  Supratcmporal 
or  prosquamosal  (after  E.  Deslongchamps). 

otic  plates.  The  paired  parietals  and  frontals  are  of  small  size,  and  a  large 
parietal  foramen  occurs  at  their  junction  in  the  median  line.  Adjoining  the 
parietals  on  either  side  are  the  large  oval  supratemporal  vacuities  (S),  bounded 


ORDER  TU 


ICHTHYOSAURIA 


167 


externally  by  the  squamosal  and  postfrontal.  The  external  nares  are  triangulär 
and  placed  close  to  the  orbits ;  the  nasals  are  extended  in  front,  and  the 
premaxillae  greatly  produced.  The  superior  border  of  the  orbit  is  formed  by 
the  postfrontal,  and  prefrontal,  the  latter  a  narrow,  triangulär  plate.  In 
front  of  the  orbit,  and  separating  it  from  the  narial  opening,  is  a  triangulär 
lachrymal.  A  long,  slender,  rod-like  jugal  bounds  the  orbit  below,  and  a 
curved  oblique  postorbital  encloses  it  behind.  Joining  the  postorbital  and 
jugal  posteriorly  is  the  quadrato-jugal,  which  forms  the  postero-lateral  angle 
of  the  skull,  and  together  with  the  quadrate  furnishes  the  connection  for  the 
lower  jaw.  An  irregularly  triangulär  or  rectangular  plate,  the  supratemporal 
(or  pr'osquamosal.  St),  is  inserted  between  the  quadrato-jugal  and  squamosal, 
and  behind  the  postorbital  and  postfrontal.  The  maxilla  is  an  elongate 
triangulär  bone,  inserted  between  the  jugal,  lachrymal,  and  premaxilla. 

The  basioccipital  (Fig.  263)  is  very  strongly  developed,  and  bears  a  stout 
articular  condyle.  Above  it  and  on  either  side  of  the  foramen  magnum  are 
the  paired  exoccipitals,  capped  by  the  b  a 

supraoccipital.  Adjoining  the  ex- 
occipitals are  the  opisthotics,  which 
remain  separate  from  the  proötics. 
The    bones    of    the    occipital    and    otic 


Fig.  263. 

Ichthyoscmrus  acutirostris,  Owen.  Upper  I-,ia.s  ; 
England.  Skull,  posterior  aspect,  1/4.  (bo,  Basi- 
occipital condyle  ;  exo,  Exoccipital  on  either  side  of 
foramen  niagnnin  ;  j,  Quadrato-jugal ;  pa,  Parietal ; 
pt,  Pterygoid  ;  '/u,  Quadrate ;  quj,  Supratemporal, 
missing  on  the  right-hand  side  ;  so,  Supraoccipital ; 
sq,  Squamosal  ;  xt,  Opisthotic),  (after  Owen). 


Ichthyosmtrus  acutirostris,  Owen.  Upper  l^ias : 
England.  A,  Palatal  aspect  of  skull,  ß,  Right 
temporal  region,  Vr,-  ich  Internal  nares  ;  pl,  Vomer  ; 
xph,  Basisphenoid,  its  rostrum  dividing  interptery- 
goid  vacuitv ;  t,  Palatine,  not  extending  so  far  in 
either  direction  as  shown.  Lettering  otherwise  as 
in  preceding  figures),  (after  Seeley). 


regions  are  rather  loosely  united,  and  the  base  and  lateral  walls  of  the  brain 
case  appear  to  have  been  cartilaginous ;  there  is  no  ossified  alisphenoid  or 
orbitosphenoid. 

Abutting  against  the  basioccipital  on  the  lower  side  of  the  skull  (Fig.  264) 
is  a  more  or  less  discoidal  basisphenoid,  which  develops  a  long,  splint-like 
anterior  process  (presphenoid),  extending  along  the  middle  of  a  large  inter- 
pterygoid  vacuity.  The  pterygoids  are  long  and  relatively  large-sized  bones 
joining  the  vomer  and  palatines  in  front,  and  the  basisphenoid  and  quadrate 
behind.  There  is  a  well-developed  columella  or  epipterygoid,  but  no  ecto- 
pterygoid  has  been  observed.  The  posterior  nares  occupy  their  primitive 
Position  on  either  side  of  the  narrow  yomers.  A  pair  of  stout,  rib-like  hyoid 
bones  is  known  to  have  been  present. 


168 


REPTILIA 


CLASS  III 


The  sleiider  rami  of  the  lower  jaw  unite  in  an  extensive  Symphysis,  and 
are  without  a  coronoid  process.  Each  ramus  consists  of  five  or  sometimes  six 
pieces.  A  deep  groove  extends  along  the  outer  side  of  the  dentary  on  its 
Upper  border,  but  becomes  interrupted  anteriorly  into  a  series  of  pits  for  the 
blood-vessels. 

The  teetli  (Fig.  265)  are  acutely  conical,  smooth  or  vertically  striate,  some- 
times with  anterior  and  posterior  carinae,  and  with  a  tumid  root  usually 
larger  than  the  crown.  As  many  as  180-200  occur  in  single  series  in  upper 
and  lower  jaws  (Fig.  266),  being  confined  to  the  maxilla,  premaxilla,  and 
dentary.     They  are  placed  in  a  deep  groove,  usually  continuous,   and  were 


Fig.  265. 

Ichthyoscncrus  platyodon,  Coiiyb.  Lower 
Lias ;  Lyme  Regis,  England.  Tooth,  lateral 
and  anterior  aspects,  i/i  (after  Lydekker). 


Fig.  266. 

Ichthyosaurus  quenstedti,  Zittel.  Upper  Jura  ; 
Würtemberg.  Jaw-fragment,  3/^.  (md,  Dentary  ; 
na,  Nasal ;  piiu;  Premaxilla),  (alter  Quenstedt). 


held  in  place  by  the  tissues  and  edges  of  the  groove.  Some  of  the  later 
Mesozoic  forms  are  edentulous.  The  crown  is  composed  of  dentine,  covered 
with  a  layer  of  enamel,  and  over  this  there  may  be  sometimes  still  another 
layer  of  cement.  A  vertical  folding  of  the  walls  similar  to  that  occurring  in 
Labyrinthodonts  is  occasionally  observed.  The  large  root  is  composed  of  an 
osseous  cement  containing  bone  cells  and  vascular  canals,  and  is  enveloped  by 
a  more  or  less  plicated  covering  of  dentine. 

The  vertebral  column  comprises  but  two  regions — caudal  and  precaudal. 
There  is  no  true  neck,  and  no  sacrum.  There  are  between  120  and  150 
vertebrae,  of  which  about  100  are  caudal.  The  centra  are  extremely  short, 
and  deeply  biconcave,  as  among  Selachians  and  Labyrinthodonts.  The  neural 
arches  are  strongly  developed,  never  fused  with  their  centra,  and  articulate 
with  one  another  by  feeble  zygapophyses.  Adult  individuals  almost  invariably 
have  the  atlas  and  axis  fused,  and  before  and  behind  each  of  them  are  sub- 
vertebral  hypocentra  or  intercentra.  The  remaining  precaudal  vertebrae  are 
of  nearly  uniform  character  (Fig.  267),  each  centrum  being  provided  with  two 
pairs  of  tubercles  for  attachment  with  the  double-headed  ribs,  and  exhibiting 
dorsally  a  neural  canal,  with  a  rugose  pit  on  either  side  for  the  pedicles  of 


ORDER  III 


ICHTHYOSAURIA 


169 


the  neural  arch.     The  anterior  caudals  bear  only  a  single  pair  of  tubercles  for 
the  Support  of  the  single-headed  ribs,  and  these  gradually  disappear  posteriorly 


Fig.  267. 

Ichthyosaurns  trigonus,  Owen.  Kimmeridge  Clay ;  Wooton- 
Basset,  England.  Posterior  dorsal  vertebra,  1/3.  a,  b,  Tuber- 
cular  and  capitular  facettes  for  ribs  (after  Lj'dekker). 


Fig.  268. 
Ichthyosaurus,  sp.     Upper  Lias  ;  Banz, 
Franconia.    Caiidal  vertebra,  i/i- 


(Fig.  268).  The  halves  of  the  chevron  bones  usually  remain  separate,  but  the 
neural  arch  of  each  vertebra  except  the  atlas  is  undivided.  A  sharp  down- 
ward  deflection  of  the  column  occurs  in  the  posterior  part  of  the  tail,  where 


Ichthyosaurus  qiiadricissus,  Quenst.     Upper  Lias  ;  Holzinaden,  Würteniberg.     Skeleton  showing 
outline  of  integument  and  dorsal  and  caudal  Ans,  i/jo  (after  E.  Fraas). 

the  vertebrae  enter  the  base  of  the  large,  triangulär  caudal  fin.  The  latter  is 
expanded  in  a  vertical  instead  of  horizontal  plane,  and  must  have  been  a  vefy 
powerful  swimming  organ.  A  median  dorsal  fin  has  also  been  observed  in  a 
specimen  from  the  Lias  of  Würtemberg  (Fig.  269). 

Ribs  are  present  on  all  the  precaudal  vertebrae,  and  reach  their  greatest 
elongation  between  the  tenth  and  thirteenth  centrum,  after  which  they 
gradually  decrease  in  size  toward  the  pelvis.  From  here  on  they  continue 
single-headed,  straight,  and  more  like  lateral  processes  than  ribs,  and  become 
obsolete  toward  the  caudal  fin.  The  long  slender  ribs  of  the  trunk  are 
recurved,  subcylindrical  in  section,  and  in  most  species  longitudinally  grooved. 
A  median  longitudinal  and  one  or  two  paired  lateral  series  of  splint-like 
abdominal  ribs  are  developed. 

The  pedoral  arch  (Fig.  270)  is  unusually  powerful,  and  indicative  of 
excellent  swimming  ability.  There  is  no  ossified  sternum  for  the  attachment 
of  ribs,  but  a  T-shaped  interclavicle  is  present  in  the  median  line,  in  part 
overlapping  the  robust  coracoids,  whose  inner  edges  meet  in  a  long  Symphysis. 


170 


EEPTILIA 


CLASS  III 


The  anterior  border  of  the  coracoids  is  somewhat  deeply  excavated,  the 
posterior  margin  entire  and  rounded.  Its  lateral  margin  is  developed  into  a 
short,  stout,  and  thickened  process  bearing  two  articular  facettes,  the  foremost 
for  receiving  the  proximal  end  of  the  scapula,  and  the  hinder  for  the  head  of 
the  humerus.  The  clavicles  are  slender  curved  bones,  usually  meeting  in  the 
middle  line  at  the  anterior  margin  of  the  interclavicle.  Their  union  may  be 
either  by  suture  or  fusion,  or  sometimes  even  by  a  Joint. 

Humerus,  radius,  and  ulna  are  all  short  stout  bones  (Fig.  271),  and 
relatively  much  reduced.  The  proximal  end  of  the  humerus  is  thickened,  the 
distal  flattened,  and  provided  with  radial  and  ulnar 
articular  facettes,  which  are  remarkable  for  being 
concave.  The  remaining  bones  of  the  paddle,  of 
which  the  first  two  rows  correspond  to  the  carpus,  and 
the  third  to  the  metacarpus,  are  small  and  polygonal, 
and  usually  arranged  in  a  sort  of  mosaic.  There  are 
commonly  from  three   to   five  digits,  but  as   some  of 


—  TT 


Fig.  270. 
Ichthyosaurus  communis,   Conyb.     JiOvver  Lias ;    England.     Pectoral 
ai'ch  and  right  fore  limb,  ventral  aspect,  1/4.     cl,  Clavicle  ;  cor,  Coracoid  ; 
h,   Humerus ;    i,   Intermedium ;    icl,   Interclavicle  (partly  covered    by 
clavicles);  K,  Radius;  r,  Radiale;  sc,  Scapula;  U,  Ulna;  «,  Ulnare. 


Fig.  271. 

Ichthyosaurus  tricissus,  Quenst. 
Upper  Lias  ;  Boll,  Würtemberg. 
Left  fore  paddle,  dorsal  aspect. 
c'.  Distal  carpals  ;  mc,  Equiva- 
lents  of  metacarpals.  Other 
letters  as  in  Fig.  270. 


the  phalangeal  rows  subdivide,  the  number  of  the  latter  is  occasionally 
increased  to  eight  or  iiine.  As  many  as  100  phalanges  are  sometimes  present. 
A  deep  incision  is  often  observable  on  the  radius  and  three  succeeding  bones 
of  the  paddle,  the  significance  of  which  is  not  understood. 

The  pelvic  arch  is  weakly  developed,  and  freely  suspended  in  the  abdominal 
muscles.  Ilium,  pubis,  and  ischium  are  all  long  and  slender  bones,  and 
apparently  meet  at  the  acetabulum.  The  femur  is  short  and  stout,  but 
relatively  longer  than  the  humerus,  and  the  rest  of  the  bind  paddle  practically 
duplicates  the  structure  of  the  anterior  limb.  The  femur  and  humerus  of  this 
Order  are  unique  in  that,  instead  of  having  convex  condyles  for  the  articulation 
of  the  epipodial  bones,  they  present  pre-  and  post-axial  concavities  for  their 
reception  (Fig.  271).  Impressions  of  the  leathery  integument  are  retained  by 
some  specimens,  as  well  as  of  the  cartilaginous  layer  which  surrounded  the 
phalanges  andcompleted  the  outline  of  the  paddles.  Dermal  armour  was  not 
developed. 


ORDER  IV  SAUROPTEEYGIA  171 

Family  1.     Ichthyosauridae. 
J'Fith  fhe  charaders  of  the  order.     Trias  to  Cretaceous. 

Mixosauras,  Baur.  Most  of  the  smaller-sized  Triassic  remains  are  placed 
in  this  genus  as  distinct  from  Ichthyosaurus,  the  teeth  being  in  less  uniform 
series,  and  the  limbs  less  completely  paddle-shaped.  The  radius  and  ulna  are 
elongated,  and  separated  by  an  interstice  throughout  their  length.  M. 
cornalianus,  Bassani,  the  typical  species,  varies  from  0*5  to  1  m.  in  length, 
and  occurs  in  the  Upper  Trias  of  Besano,  Lombardy.  31.  ataviis,  Quenstedt, 
is  known  by  fragments  from  the  Muschelkalk  of  Würtemberg. 

Ichthyosaurus,  König  (Figs.  262-271).  Teeth  conical  and  in  uniform  series. 
Kadius  and  ulna  shorter  than  broad,  proximally  in  contact.  Humerus  and 
femur  with  two  concave  distal  facettes.  Total  length  of  largest  forms  upwards 
of  10  m.  • 

This  genus  is  most  abimdant  in  the  Lias,  J.  communis  and  I.  intermedius  being 
familiär  English  species.  Localities  noted  for  the  excellence  of  their  fossil  remains  are 
Dorsetshire  (Lyme  Regis)  and  Somersetshire  in  the  Lower  Lias,  and  Yorkshire,  Cal- 
vados, Würtemberg  (Boll,  Holzmaden),  and  Franconia  (Banz,  Altdorf)  in  the  Upper 
Lias ;  and  the  species  of  the  one  division  are  for  the  most  part  distinct  from  those  of 
the  other.  /.  communis,  intermedius,  latimanus,  platyodon,  and  tenuirostris  are 
especially  characteristic  of  the  Lower  Lias,  and  /.  acutirostris,  ingens,  quadricissus, 
and  trigonodon  of  the  upper  membe?.  Remains  of  Ichthyosaurus  are  spai-se  in  the 
Middle  Jura,  but  a  number  of  species  occur  in  the  Upper  Jura  of  Solenhofen  and 
Kelheim,  Bavaria,  Northern  France,  and  England.  Cretaceous  forms  are  known  from 
England,  France,  the  East  Indies,  Australia,  New  Zealand,  and  Chili. 

Ophthalmosaurus,  Seeley.  Edentulous  or  with  minute  teeth  confined  to 
front  of  the  jaw.  Humerus  and  femur  with  prominent  trochanteric  ridge 
and  with  three  concave  distal  facettes ;  all  remaining  limb  bones  more  or  less 
rounded  and  separated.  Clavicles  separated.  Upper  Jura  and  Lower  Creta- 
ceous ;  England. 

Baptanodon,  Marsh  (Sauranodon,  Marsh  non  Jourdan).  Similar  to  the 
preceding,  but  completely  edentulous.  Interclavicle  not  observed ;  digit 
arising  from  the  intermedium  consisting  of  two  longitudinal  rows  of  ossicles. 
Coracoids  unite  in  the  median  line  in  large  elliptical  facettes.  Upper  Jura ; 
Wyoming. 

Shastasaurus,  Merriam.  Includes  several  large  species  from  the  Upper 
Trias  of  northern  California.  Pelvis  very  robust ;  all  but  first  ten  ribs  single- 
headed.  Cymbospondylus,  Leidy,  from  Middle  Trias  of  Nevada,  is  imperfectly 
known. 

Order  4.     SAUROPTERYGIA.     Owen.i 

■Primitive  aquatic  reptiles  with  long  neck,  lizard-like  body,  and  moderately  shorf 
tail.      Cranium  small,  with  parietal  foramen  and  large  supratemporal  vacuities. 

^  Andrews,  ö.  W.,  On  Plesiosaurus,  Pliosaurus,  etc.  (Quar.  Journ.  Geol.  Soc.  vol.  XXXVII.  p.  440), 
1881.— Also  ibid.  vol.  LIII.  (1897),  p.  177,  and  vaiious  articies  in  Geol.  Mag.  [4],  vol.  II.  (1895),  p.  241  ; 
ibid.  vol.  III.  (1896),  p.  145  ;  Ann.  Mag.  Nat.  Hist.  [6],  vol.  XV.  (1895),  p.  333  ;  ibid.  vol.  XVI. 
(1895),  p.  429. — Bassani,  F.,  Sui  fossili  degli  schisti  bituminosi  triassici  di  Besano  (Atti  Ist.  Veneto 
Sei.),  l8SQ.~Beneden,  P.  J.  van,  Deux  Plesiosaures  du  Lias  inf^rieure  du  Luxembourg  (Mem.  Aead. 
Roy.  Belg.  vol.  XLIII.  p.  1),  \8%().—Boulenger,  O.  A.,  On  a  Nothosaurian  Reptile  referable  to 
Lariosaurus  (Trans.  Zool.  Soc.  vol.  XIV.  p.  1),  1896.— Cope,  E.  />.,  On  the  structure  of  the  skull  in 


172 


KEPTILIA 


CLASS  III 


Imesting  hones  of  temporal  region  forming  a  single  h'oad  arcade  ;  quadrate  fixed. 

Fremaxillae  not  elongated ;  pterygoids   extensive,  meeting  along  the  middle  line  ; 

narial  openings  divided.  Teeth  conical,-  thecodont, 
in  Single  series  along  margin  of  jaws.  Vertebrae 
amphiplatyan ;  sacrum  composed  of  two  to  foiir 
vertebrae.  Cervical  ribs  articulating  only  with 
centra,  never  with  their  arches ;  dorsal  ribs  single- 
headed ;  abdominal  ribs  present  between  the  robust 
limb  girdles ;  no  ossified  sternum.  Limbs  more 
or  less  completely  paddle- shaped,  pentadactylate. 
Humerus  with  entepicondylar  foramen,  and  large 
conical  epiphyses ;  digits  sometimes  with  super- 
numerary  phalanges.  Dermal  armour  and  sclerotic 
ring  not  developed. 

This  reptilian  order  ranges  from  the  Trias 
to  the  end  of  the  Mesozoic  era.  The  earlier 
forms  are  mostly  small  amphibious  animals 
with  slender,  elongated  limbs,  and  the  later 
ones  large-sized  and  completely  adapted  for 
a  marine  existence. 

Family  1.     Nothosauridae. 


Fig.  272. 

Lariosaurus  halsami,  Curioni.  Muschel 
kalk ;  Perledo  on  Lake  Como,  Lombardy 
Skeleton,  dorsal  aspect,  i/iq. 


Limbs  comparatively  slender  and  elongated, 
with  five  digits  and  normal  number  of  phalanges. 
Coracoids  not  much  extended  along  their  median 
Symphysis,  and  not  in  contact  with  interclavicle  : 
scapulae  well  separated  by  a  clavicular  arch. 
Trias. 

Lariosaurus,  Curioni  {Macromirosaiirns, 
Cur.),  (Fig.  272).  Body  lizard-like,  20-90  cm. 
long,  tail  forming  about  one-third  the  total 
length.  There  are  about  twenty  cervicals, 
twenty-four  to  twenty-six  dorsals,  four  sacrals, 
and  over  forty  caudals.  Cervical  ribs  small 
and  double-headed  ;  dorsal  ribs  very  robust, 
and  borne  directly  by  the  neural   arches.     A  median   longitudinal  and  two 

the  Plesiosaurian  Reptilia  (Pi-oc.  Amer.  Phil.  Soc.  vol.  XXXIII.  p.  110),  1894.  — />«?«<?«,  W., 
(Abhaudl.  preuss.  Akad.  Wiss.  p.  1),  1895. — Deecke,  W.,  Ueber  Lariosaurus,  etc.  (Zeitschr.  deutsch, 
geol.  Ges.  vol.  XXXVIII.  p.  170),  \^%Q.—HawMns,  T.,  Memoirs  on  Jchthyosauri  and  Plesiosaiiri. 
London,  \%M.—Hulke,  J.  W.,  Anniversary  Address  (Quar.  Journ.  Geol.  Soc.  vol.  XXIX.),  1893. 
Also  Proc.  Roy.  Soc.  vol.  LI.  (1892). — Hiixley,  T.  //.,  On  Plesiosaurus,  etc.  (Quar.  Journ.  Geol.  Soc. 
vol.  XIV.  p.  281),  1858. — Knight,  W.  C,  Some  new  Jiirassic  Vertebrates  from  Wyoming  (Amer. 
Journ.  Sei.  [4],  vol.  V.  p.  378),  1898.  Also  ibid.  vol.  X.  (1900),  p.  Wh.— Meyer.  H.  von,  Zur  Fauna 
der  Vorwelt,  pt.  II.  Frankfort,  184:7 .—Owen ,  jR.,  Monograph  of  the  fossil  Reptilia  of  the  Liassic 
Formations,  pt.  III.  (Palaeontogr.  Soc),  1865.  Also  Geol.  Mag.  vol.  VII.  (1870),  p.  49  ;  and  Quar. 
Journ.  Geol.  Soc.  vol.  XXXIX.  (1883),  p.  ISS.Seeley,  H.  G.,  The  nature  of  the  Shoulder  girdle  and 
clavicular  arch  in  Sauropterygia  (Proc,  Roy.  Soc.  vols.  LI.  p.  119,  and  LIV.  p.  160),  1892-93.  Also 
various  articles  in  Ann.  Mag.  Nat.  Hist.  [3],  vol.  XV.  (1865),  pp.  49,  232  ;  vol.  XVI.  (1865),  p.  352  ; 
[4],  vol.  VIII.  (1871)  ;  Quar.  Journ.  Geol.  Soc.  vol.  XXX.  (1874),  pp.  197,  436  ;  vol.  XXXIII. 
(1877),  p.  541  ;  vol.  XXXVIII.  (1882).  p.  350  ;  Ann.  Rep.  Yorks.  Phil.  Soc.  (1895),  p.  2Q.—SoUas, 
W.  F.,  On  Plesiosaurus  conybearei  (Quar.  Journ.  Geol.  Soc.  vol.  XXXVII.  p.  440),  1881.— 
Williston,  S.  W.,  A  new  Plesiosaur,  etc.  (Trans.  Kansas  Acad.  Sei.),  1890. 


ORDER  IV 


SAUEOPTEEYGIA 


173 


paired  lateral  series  of  abdominal  ribs  present.  Proximal  tarsals  consisting  of 
two  large  elements,  the  distal  five  each  supporting  a  digit ;  phalangeal  formula, 
2,  3,  4,  4,  3.  Hind  limb  longer  and  stouter  than  the  anterior,  but  otherwise 
very  similar ;  phalangeal  formula  2,  3,  4,  5,  4.  Pakte  with  suborbital  and 
infratemporal  vacuities,  but  no  interpterygoidal.  Middle  Trias ;  Lake  Como, 
Italy. 

Pachypleura,  Cornalia  (Neusticosaurus,  Seeley).     Similar  to  the  preceding 
but  smaller  (25-30  cm.  long),  with  much  shorter  neck;  about  sixteen  cervicals 


Fig.  27; 

Nothosauriis  mirabilis,  Münst.  Muschelkalk  ;  Bayreuth,  Gennany.  Skull,  slightly 
restored,  1/4.  A,  Dorsal  aspect  (after  Quenstedt).  B,  Lateral  aspect.  C,  Palatal  aspect 
(after  v.  Meyer).  A,  Orbit;  ang,  Angular ;  art,  Surangular;  bo,  Basioccipital  condyle ; 
ch,  Internal  nares ;  d,  Dentary ;  fr,  Frontal;  G,  Infratemporal  vacuity ;  j,  Jugal;  k, 
Articular ;  md,  Mandible  ;  onx,  Maxilla ;  N,  External  narial  openiug ;  na,  Nasal ;  pa. 
Parietal ;  pl,  Palatine ;  pmx,  Preniaxilla ;  prf,  Prefrontal ;  pt,  Pterygoid,  bounded  in 
iront  by  voiner  (suture  not  shown) ;  ptf,  Postfrontal ;  qri,  Quadrate  ;  qvj,  Quadrato-jugal 
fused  with  squamosal  and  suprateniporal ;  S,  Supratemporal  vacuity. 


Fig.  274. 

Tooth,  1/1.  of 
species  shown  in 
Fig.  273. 


Fio,  275. 

Cervical  vertebra, 
1/1,  of  species 
shown  in  Fig.  273. 
A,  B,  Dorsal  and 
lateral  aspects. 


and  forty  caudals.  Upper  Trias  (Raibl  Beds) ;  Besano,  Lombardy,  also  Letten- 
kohle of  Hoheneck,  near  Ludwigsburg. 

Dadylosaurus^GüTich;  Jnarosaurus,  Bannes;  CymatosauruSy  J)a.mGS.  Muschel- 
kalk ;  Silesia  and  Thuringia. 

Nothosaurus,  Münst.  (Figs.  273-277).  Distinguished  from  Lariosaurus  by 
its  larger  size,  closure  of  suborbital  vacuity  in  the  palate,  and  presence  of  short 
and  stout  transverse  processes  on  neural  arches  of  dorsal  vertebrae. 

The  skull  is  elongated  and  somewhat  contracted  anteriorly,  attaining  a  lengtli  of 
35  cm.  in  the  typical  species.  The  supratemporal  vacuities  are  very  large,  th£  uu- 
paired  parietal    being  reduced   to  a  narrow  bar,  pierced  posteriorly  by  a  parietal 


174 


EEPTILIA 


CLASS  III 


foramen.  The  orbits  are  oval,  relatively  small,  and  placed  sliglitly  in  front  of  tlie 
middle ;  not  far  removed  from  them  are  the  external  nares.  The  unpaired  frontal  is 
much  elongated,  the  premaxillae  only  moderately  so,  and  the  prefrontals  are  small  and 
triangnlar,     The  long  and  narrow  maxillae  nnite  posteriorly  with  a  slender  jugal, 


FiG   270. 

Nothosaurus  imrahüis,  Münst.     Muschelkalk  ;  Bayreuth,  Germany.    A,  The  five  anterior  cervicals. 
B,  Tvvo  dorsals.     C,  Three  caudal  vertebrae,  1/2  (after  von  Meyer). 

which  entei-s  into  the  temporal  arcade.  Pterygoids  and  palatines  are  strongly 
developed  ;  the  internal  nares  are  placed  far  forwards,  on  either  side  of  the  paired 
vomer.     A  Single  series  of  conical,  slightly  curved,  and  striated  teeth  (Fig.  272)  is 

borne  by  the  maxillae,  pre- 
maxillae, and  dentary.  All  of 
the  rostral  and  one  or  two  of 
the  anterior  maxillary  teeth  are 
considerably  enlarged. 

O'sving  to  the  sutural  union 
between  the  vertebral  centra  and 
their  neural  arches,  the  former 
are  usnally  found  detached  in 
the  fossil  State,  and  exhibit  a 
crnciform  Impression  on  the 
dorsal  surface  (Fig.  275).  There 
are  about  twenty  cervicals  (Fig. 
276),  all  of  which  excepting  atlas 
and  axis  bear  short,  curved, 
double-headed  ribs.  The  ribs  of 
the  trank  region  are  stout,  single- 
headed,  and  attached  to  the  trans- 
verse  processes  of  the  neural 
arches.  In  tliis  region  the 
neural  spines  are  more  strongly 
developed,  and  the  zygapophyses 
more  weakly,  than  elsewhere  in 
the  vertebral  column.  The  caudal  vertebrae  have  single-headed  ribs  attached  to  their 
centra,  and  also  small  chevron  bones.  The  abdominal  ribs  comprise  a  median  longi- 
tudinal  series  sharply  bent  in  the  middle  line,  and  a  paired  lateral  series. 

In  the  pectoral  arch  (Fig.  277)  the  cla vieles  are  well  developed,  and  form  a  regulär 
arch  into  which  a  small,  oval  interclavicle  entere.     The  ends  of  the  clavicular  arch  are 


Fig.  277. 

Nothosaurus  mirabilis,  Münst.  Muschelkalk ;  Bayreuth,  Ger 
many.  Dorsal  aspect  of  pectoral  arch,  1/5.  d,  Clavicle  ;  cor,  Cora 
coid  ;  icl,  Interclavicle  ;  sc,  Scapula. 


ORDER  IV  SAUROPTERYGIA  175 

siiturally  united  Avitli  a  pair  of  stout  scapulae,  wliicli  develop  oblique  dorsal  processes. 
The  coracoids  are  not  much  extended  in  the  median  line,  and  tlieir  antero-internal 
niargin  is  notched  and  incomplete ;  apparently  the  space  between  them  and  the 
clavicular  arch  was  filled  during  life  by  cartilage.  The  humerus  is  moderately  long, 
curved,  and  very  robust ;  it  is  pierced  distally  by  an  entepicondylar  foramen.  Radius, 
ulna,  and  metacarpals  are  likewise  rather  long  and  slender,  the  paddle-shaped  form  of 
limb  being  not  yet  fully  acquired. 

The  bones  of  the  pelvic  arch  are  robust,  and  owing  to  tlieir  loose  articulation, 
usually  occur  detached  in  the  fossil  state.  The  ilium  is  very  short  and  stout,  some- 
what  expanded  distally,  and  provided  with  two  articular  facettes.  Pubis  and  ischium 
are  both  of  large  size,  narrowed  and  thickened  at  the  acetabulum,  and  distally  ex- 
panded ;  a  small  obturator  foramen  persists  in  the  pelvis.  The  femur  is  longer  and 
more  slender  tlian  the  humerus,  nearly  rectilinear,  moderately  thickened  at  the 
extremities,  and  with  rounded  articular  faces.  The  remaining  bones  of  the  bind  liml) 
are  imperfectly  known. 

Nothosaurus  is  an  exclusively  Triassic  genus,  and  occurs  most  abundantly  in  the 
Muschelkalk  of  Southern  Germany.  N.  miraUlis,  Münster,  is  the  typical  and  best- 
known  species,  attaining  a  length  of  fully  3  m.  Smaller  species  are  known  from  the 
Buntsandstein  and  Lettenkohle.  The  so-called  Parthanosaurus,  Skuphos,  from  the 
Raibl  Beds  of  Vorarlberg,  is  doubtfully  distinct. 

Coiichiosaurus,  v.  Meyer.     Muschelkalk;  Esperstädt,  Brunswick. 

Swiosaurus,  v.  Meyer.  Skull  broad  and  depressed,  with  obtuse  snout. 
Teeth  short,  obtusely  conical  or  clavate,  the  crown  strongly  striated.  Muschel- 
kalk and  Lettenkohle. 

Pistosaurus,  v.  Meyer.  Known  only  by  the  skull,  w^hich  tapers  anteriorly, 
and  attaihs  a  length  of  35  cm.  Premaxillae  elongate  and  slender,  the  small 
narial  openings  placed  between  them  and  the  maxillae.  Nasals  greatly 
reduced  and  displaced  posteriorly.  Palate  with  an  unpaired  vacuity  between 
the  premaxillae.  Muschelkalk ;  Franconia  and  Silesia.  This  genus  is  made 
by  Baur  the  type  of  an  independent  family. 

Family  2.     Plesiosauridae. 

Limhs  paddle-shaped,  bones  of  second  segment  much  shortened,  and  the  five  digits 
elongated  by  supernumerary  phalanges.  Clavicular  arch  tending  to  diminish  in  size 
as  the  scapidae  increase,  the  latter  sometimes  becoming  fused  with  each  other  and  the 
coracoids  in  the  median  line.  Coracoids  much  extended  along  median  Symphysis, 
and  uniting  with  either  the  scapular  or  clavicular  arch  anteriorly.  Sclerotic  plafes 
present.     Trias  to  Cretaceous. 

Plesiosaurus,  Conyb.  (Figs.  278-280).  Head  small,  neck  very  long,  tail  of 
moderate  length.  Snout  not  elongated,  orbits  elliptical  and  placed  near  the 
middle  of  the  skull,  supratemporal  vacuities  large,  irregulär.  External  nares 
small  and  close  to  the  orbits.  Postero- lateral  angles  prominent.  Inter- 
pterygoidal  and  posterior  palatine  vacuities  small.  Mandibular  Symphysis 
short.  Teeth  acutely  conical,  longitudinally  grooved ;  anterior  ones  some- 
what  enlarged.  Coracoids  meeting  in  a  long  Symphysis,  scapulae  separated 
by  a  well-developed  clavicular  arch. 

The  iiumber  of  cervical  vertebrae  varies  among  the  ditferent  species  between  thirty 
and  forty.  The  centra  are  but  slightly  biconcave,  and  united  to  the  neural  arches 
by  suture  ;  the  marks  of  their  attachment  form  with  the  neural  canal  a  cruciform 


176 


EEPTILIA 


CLASS  III 


impressioii  on  the  dorsal  side  of  the  centra.  With  the  exception  of  atlas  and  axis,  all 
the  cervicals  bear  short,  double-headed  ribs,  attached  directly  to  tlie  centra.  Tkere 
are  about  twenty  dorsal  vertebrae  with  well-developed  transverse  processes  and  single- 
headed  ribs.  The  two  sacral  vertebrae  are  cliaracterised  by  baving  somewhat  sborter 
transverse  processes  and  broader  ribs  than  tbe  rest.  There  are  between  tbirty  and 
forty  candals,  most  of  which  bear  short,  single-beaded  ribs  articulated  with  their  centra, 

and    chevron    bones    whose 

f^''Xf'^^^--<^f;%!\scr+s.t^<lj.  right  and  left  halves  do  not 

P^f      Jv-^  \.0  \  /  fuse  below.     The  abdominal 

ribs  are  very  robust,  and 
consist  of  a  median  and  three 
paired  lateral  series. 

In  the  pectoral  arch  (Fig. 
279)  the  coracoids  are  char- 
acterised  by  their  large  size, 
being  considerably  longer 
than  broad,  and  joined  in 
a  long  median  Symphysis. 
There  is  no  sternum,  and  as  a 
rule  no  separate  interclavicle, 
but    the    clavicular   arch    is 


Fig.  278. 

Plesiosaurus  macrocephalus,  Owen.  Lower  Lias ;  Lyme  Regis, 
Dorsetshire.  A,  Lateral ;  J5,  Superior  ;  C,  Palatal  aspects  of  skull,  Vß- 
ag,  Angular ;  art,  Articular ;  bocc,  Basioccipital ;  bs,  Basisphenoid  ; 
d,  dentary ;  eept,  Transversa  or  ectopterygoid ;  fr,  Frontal ;  ipt,  Inter- 
pterygoid  vacuity ;  j,  Jugal ;  mx,  Maxilla ;  nar,  External  narial  openiug ; 
orb,  Orbit ;,  pa,  Parietal ;  pas,  Parasphenoid  ;  pin,  Pineal  foranien  ;  pl, 
Palatine  ;  pinx,  Premaxilla  ;  prf,  Prefrontal ;  pt,  Pterygoid  ;  ptnar,  Pos- 
terior nares  ;  ptf,  Postfrontal ;  pto,  Postorbital ;  qj,  Quadrato-jugal ; 
qu,  Quadrate  ;  s,  Supratemporal  vacuity ;  sag,  Surangular ;  so,  Sub- 
orbital vacuity  ;  st,  Supratemporal  or  prosquamosal ;  sq,  Squamosal ; 
V,  vomer  (from  Woodward,  after  Andrews). 


Fig.  279. 

Plesiosaurus  laticeps,  Owen. 
Lower  Lias  ;  Dorsetshire.  Pectoral 
arch,  ventral  aspect,  ^/lo-  c?, 
Clavicle  ;  cor,  Coracoid  ;  icl,  Inter- 
clavicle ;  sc,  Scapula. 


represented  by  a  single,  broad,  bilaterally  symmetrical  bone  to  which  the  coracoids  and 
scapulae  are  firmly  united.  The  latter  are  somewhat  extended  ventrally  underneath 
the  clavicular  arch,  but  do  not  meet  in  the  median  line. 

The  humerus  is  robust  and  distally  much  expanded,  but  without  epicondylar 
foramen  or  groove.  This  bone  and  the  femur  are  noteworthy  as  exhibiting  large, 
conical  epiphyses,  similar  to  those  of  frogs  and  certain  Chelonians.  The  radius  and 
ulna  are  both  a  little  longer  than  broad.  Four  elements  are  usually  present  in  the 
proximal,  and  three  in  the  distal  row  of  the  carpus ;  the  five  constricted  metacarpals 
are  similar  in  form  to  the  phalanges.  The  phalangeal  formula  is  inconstant,  but  the 
third  and  fourth  digits  are  always  the  longest,  sometimes  comprising  as  many  as  nine 
phalanges.     The  bind  limb  differs  in  no  respect  from  the  fore,  except  that  it  is  slightly 


ORDER  IV 


SAUROPTERYGIA 


177 


stouter.  Probably  both  were  invested  witli  a  cartilaginous  membraiie,  as  in  Ichthyo- 
saiirs.  Tlie  piibes  are  relatively  large,  with  convex  anterior  and  notched  posterior 
margin,  but  not  pierced  by  a  foramen.  They  meet,  as  do  also  the  much  smaller  ischia, 
in  a  long  median  Symphysis.  The 
ilium  is  slender,  and  articulated  only 
with  the  ischium. 

Several  nearly  perfect  skeletons  of 
Plesiosaurus  are  known  from  the 
Lower  and  Upper  Lias  of  England 
and  Germany,  and  supposed  fragments 
are  known  from  the  Rhaetic.  The 
typical  species,  P.  dolichodeirus,  Cony- 
beare,  from  the  Lower  Lias  of  Lyme 
Regis,  England,  attains  a  total  length 
of  3  m.  Other  species  from  the  same 
locality  are  P.  hawkinsi,  P.  rostratus, 
and  P.  macrocephalus,  Owen  ;  and  P. 
conybearei,  Sollas,  the  latter  sometimes 
attaining  a  length  of  5  m.  Beautiful 
skeletons  are  preserved  in  the  British 
and  Berlin  Museums.  Several  North 
American  species  have  been  referred 
to  this  genus. 


Eretmosaurus,  Seeley.  Cora- 
coids  truncated  anteriorly,  and  not 
extending  in  front  of  the  glenoid 
cavity  for  the  humerus.  Scapulae 
extending  downward  and  inward 
so  as  to  become  fused  with  each 
other  and  also  with  coracoids  in 
the  median  line.  Clavicular  arch 
degenerate.  Lower  Lias ;  Eng- 
land. 

Ehomaleosaurus,  Seeley.  K 
cramptoni,  Carte  sp.  Colpnbosaurus, 
Muraenosaurus,  Seeley.  Upper 
Jura ;  England. 

Cnjptoclidus,  Seeley.  Resembles 
Plesiosaurus,  except  that  the  ribs 
are  all  single-headed,  and  pectoral 
arch  is  like  that  of  Eretmosaurus, 
Elasmosaunis,    etc.      Upper    Jura ;  ^^^  28o 

ILIlgiana.  PleMosauruf!  dol-khodeirns,  Conyb.     Lower   Lias  ;   Lyme 

CimoliasaurUS,  OligOsimUS,  Brimo-    j^^gi« !   WorsetsUire.     Skeleton,  ventral  aspect,  Vi3  (after 

saurus,  Leidy  ;  Fiptomerus,   Orophor 

saurus,  Emhaphias,  Polycotylus,  Üronautes,  Cope ;  Trinacroinerum,  Cragin ;  Maui- 
saurus,  Hector.  These  genera  from  the  Upper  Cretaceous  of  North  and  South 
America  and  New  Zealand  are  for  the  most  part  yet  insuflBciently  characterised, 
and  include  very  diverse  forms.     The  first-named  is  also  European. 

Pliosaurus,  Owen  (Ischyrodon,  Thaumatosaurus,  v.  Meyer ;  Pelomustes,  Lydd. ; 
Liopleurodon,  Sauv.),  (Fig.  281).     Gigantic  Plesiosaurs  with  relatively  large 

VOL.  II  N 


178 


EEPTILIA 


CLASS  m 


head  and  short   neck.      Skull  depressed  and   narrow,  attaining   a   length  of 

1"3  m.  Internal  nares  remotely  situated,  mandibular  Symphysis  considerably 
extended.  Margin  of  upper  jaw  on  either  side  with  a  series 
of  about  thirty  powerful  carinated  teeth,  sometimes  25  cm. 
long ;  the  crown  traversed  for  a  portion  of  its  height  by 
strong  elevated  ridges.  About  twenty  very,  short  cervicals 
with  double-headed  ribs.  Limb  girdles  similar  to  those  of 
Plesiosaurus.  Lias  to  Upper  Jura  ;  England,  Northern  France, 
Switzerland,  Bavaria,  Russia,  and  India. 

3Iegalneusmirus,  Knight.  Largest  known  Plesiosaur,  the 
humerus  attaining  a  length  of  1  m.,  or  about  one-half  the 
length  of  the  entire  fore-limb,  and  articulating  only  with 
the  radius  and  ulna.  The  latter  bones  are  polygonal  and 
closely  applied  against  each  other  and  the  three  proximal 
carpals.  Coracoids  produced  in  front  of  the  glenoid  cavity  ; 
vertebrae  elongated.  Upper  Jura ;  Wyoming.  M.  rex, 
Knight. 

Elasmosaurus,  Cope  (Fig.  282).  A  skeleton  in  Philadelphia 
lacking  the  head  exceeds  13  m.  in  length.  The  seventy-two 
cervicals  are  longer  than  deep,  and  bear  short,  single-headed 
ribs.  The  neural  arches  are  all  fused  with  their  centra,  but 
the  chevron  bones  are  articulated  with  the  caudals.  Pectoral 
arch  similar  to  that  of  Cryptodidus.  Limbs  and  greater  part 
of  the  skull  unknown.     Upper  Cretaceous  ;  Kansas. 

Dolichorhynchus,  Willist.     Head  long,  snout  very  slender ; 
mandibular  Symphysis  much  elongated;  teeth  small,  numerous; 
vomers  very   long ;    posterior  nares  small,  included  between 
vomer    and    pala- 
no  posterior  palatine  fora-  .«m^-t— ™^  ® 

pterygoids  contiguous  only 

at  extremities.     Neck  shorter  than 

head  ;  cervical  ribs  single-headed  ; 

axis  with  ribs ;  nineteen  cervicals 

and  about  thirty  dorsals  are  pre- 

sent ;     tail    very     short,     conical. 

Clavicular     arch      complete,     the 

clavicles  articulating  with  the  long 

precoracoidal     process.        Ischium 

elongate.       Humerus    and    femur 

moderately   expanded ;   three  pro- 

podials.     Known  by  a  nearly  com- 
plete skeleton  about  3  m.  in  length   Upper   Cretaceous- 

e  ii         -NT«    1  ri      i  j?     Pectoral    arch,     sha 

irom    the    JNlObrara    Cretaceous    OI    restored;  greatlyreduced 

Kansas. 

Polyptychodon,  Owen  (Fig.  283). 
Imperfectly  known,  teeth  resembling  those  of  Fliosaurus,  but  with  more 
prominent  coronal  ridges,  some  of  which  extend  to  the  apex.  Middle  and 
Upper  Cretaceous ;  England,  Germany,  and  Russia. 


Fig.  281. 
PliosuurtLS  grandis, 
Owen.  Kimmerid- 
gian ;  Dorsetshire. 
Tooth,  1/4  (after 
Owen). 

tines 
mina 


Fig.  282. 

Elasmosaurus  platyurus,  Cope. 
Kansas. 


Coracoid 
Cope). 


cor, 
sc,    Scapula    (after 


inter- 
rupttis,  Owen.  Ceno- 
m  a  n  i  a  n  ;  K  e  1  h  e  i  ni 
Bavaria.     Tooth,  l/j. 


OKDKH  V  THEROMORPHA  179 


Order  5.      THEROMORPHA.      Cope.     {Anomodontia,  Seeley,  non  Owen.)  ^ 

rrimitive  land  reptiles  with  more  or  less  hiconcave  vertebrae  and  limbs  adapted  for 
habitiial  support  of  the  body.  Investing  bones  of  temporal  region  either  forming  a 
continuous  shield  or  contracting  into  a  single  broad  arcade,  sometimes  irregularly 
perforated.  Quadrate  fixed,  often  reduced  in  size.  Pineal  foramen  preserä.  Teeih 
thecodont,  occasionally  wanting.  Pectoral  arch  with  well-developed  epicoracoids 
(precoracoids),  clavicles,  and  J-shaped  interclavicle,  besides  scapulae  and  coracoids. 
All  the  elements  in  both  limb  girdles  either  fused  or  immovably  united  by  suture. 
Humer  US  with  entepicondylar  foramen  and  prominent  delto-pectoral  er  est.  Extremities 
pentadactylate.  Sacrum  consisting  of  two  to  six  vertebrae  ;  anterior  ribs  completely  or 
imperfectly  double-headed,  abdominal  ribs  wanting. 

Many  widely  dissimilar  characters  are  exhibited  by  the  various  groups  of 
ancient  reptiles,  which  have  received  the  general  designation  of  Tkeromarpha, 
in  allusion  to  their  resemblance  in  certain  skeletal  peculiarities  to  the  lowest 
mammals  (Monotremata).  They  are  also  often  called  Anomodonts,  on  account 
of  their  remarkable  dentition.  There  can  be  no  doubt  that  these  creatures 
occupy  an  intermediate  position  between  the  high  est  Labyrinthodonts,  such  as 
Mastodonsaurus,  and  monotreme  mammals ;  and  it  is  altogether  probable  that 
from  amongst  some  of  their  number  with  one  robust  zygomatic  arch  and 
triconodont  teeth,  the  Mamm,alia  arose. 

Theromorphous  reptiles  represent  not  only  a  transitional  stage  between 
mammals  and  amphibians,  but  they  form  a  collective  group,  uniting  in  them- 
selves  characters  that  are  elsewhere  found  distributed  amongst  various 
subdivisions  of  both  reptiles  and  mammals.  No  other  reptilian  order  has 
the  three  elements  of  the  pelvic  arch  on  each  side  fused  into  an  innominate 
bone,  as  in  mammals.  The  intimate  union  of  the  bones  of  the  pectoral  arch  is 
paralleled  among  the  Salamandridae  and  Sauropterygia  ;  and  the  sacrum,  formed 
sometimes  of  a  number  of  vertebrae,  resembles  that  of  Dinosaurs  and  mammals. 
The  dißerentiation  of  the  marginal  teeth  into  incisors,  canines,  and  molars,  and 
the  occasional  development  of  a  strikingly  mammalian  form  of  limb  (Therio- 
desnius)  and  a  tripartite  or  even  dicondylic  basiocciput  {Cynognathus),  are 
significant  characters.  A  distinguishing  feature  between  this  order  and 
Squamata  is  the  fixation  of  the  quadrate ;  and  the  absence  of  a  lateral 
temporal  vacuity,  with  an  arcade  above  and  below,  distinguishes  it  from  all 
other  Archosauria  (Rhynchocephalians,  Dinosaurs,  Crocodiles,  and  Pterosaurs). 

The  term  Anomodontia,  although  restricted  by  Owen  to  the  group  of 
Dicynodonts,  is  made  synonymous  by  some  authors  with  Theromm'pha,  or 
Theromora,  as  they  are  sometimes  called. 

^  Literature  : 

Cope,  E.  Z).,  The  Reptilian  order  Cotylosauria  (R'oc.  Amer.  Phil.  Soc.  vol.  XXXIV.  p.  436),  1896. 
—Ibid.  vol.  XXXV.  (1896),  p.  \2%— Newton,  E.  T.,  Some  new  Reptiles  from  the  Elgin  Sandstone 
(Phil.  Trans,  vol.  CLXXXIV.  p.  436),  1893.— 0?<;e??,  R.,  On  Dieynodon  (Trans.  Geol.  Soc.  vol.  VII. 
p.  59),  1845.— On  some  Reptilian  fossils  from  South  Africa  (Quar.  Journ.  Geol.  Soc.  vol.  XVI.  p.  49), 
imO.—Ibid.  vols.  XXXII.  (1876),  p.  95  ;  XXXVI.  (1880),  p.  414  ;  XXXVII.  (1881),  p.  261  ;  and 
XL.  (1884),  p.  146.— On  Dicynodont  Reptiles  (Phil.  Trans,  vol.  CLII.  p.  442),  1862.— Catalogue  of  the 
fossil  Reptilia  of  South  Africa  in  the  British  Museum.  London,  l%1Q.— Seeley,  H.  G.,  Researches 
on  the  Anomodont  Reptiles  and  their  allies  (Phil.  Trans,  vol.  CLXXIX.  p.  59),  1888.— /6?"c?.  vols. 
CLXXX.  (1889),  p.  215  ;  CLXXXIII.  (1892),  p.  311  ;  CLXXXIV.  (1893),  p.  488  ;  CLXXXV.  (1894), 
p.  987  ;  and  CLXXXVI.  (1895),  p.  59.  Also  Ann.  Mag.  Nat.  Hist.  [7],  vol.  i.  (1898),  p.  164,  and 
Quar.  Journ.  Geol.  Soc.  vol.  LVI.  (1900). 


180 


EEPTILIA 


CLASS  III 


Sub-Order  I.     PAREIASAURIA.     Seeley.     (Cotylosauria,  Cope.) 

Head  completely  covered  hy  a  hony  roof ;  parietal  foramen  large  ;  narial  openings 
separate.  Marginal  teeth  arranged  in  a  more  or  less  uniform  series.  Vertebral 
centra  pierced  for  the  persistent  notochord. 

The  skeletal  characters  of  this  group  proclaim  a  very  close  relationship 
with  the  higher  Labyrinthodont  Amphibians.  In  the  typical  genus,  Pareia- 
saurus,  the  external  bones  of  the  skull  are  sculptured,  but  no  true  mucous 
canals  have  been  observed. 


Family  1.    Pareiasauridae.     Cope. 


Teeth  conical,  or  with  compressed,  cuspidate  crown,  those  on  the  margin  of  the  jaws 
arranged  in  close  regulär  series.  Smaller  teeth  usually  present  on  palatines,  pterygoids, 
and  vomers.  Pelvic  bones  fused  in.  the  adult.  Limbs  short  and  stout.  Permian 
and  Trias. 

Fareiasaurus,  Owen  (Fig.  284).  Known  by  tolerably  complete  skeletons 
over  2 '5  m.  long  from  South  Africa  and  Northern  Eussia.  Skull  broad, 
depressed,  and  triangulär  in  form,  the  external  bones  coarsely  sculptured,  but 
their  sutures  not  clearly  distinguishable.     Orbits  relatively  small,  laterally 


Fig.  284. 

Fareiasaurus  haini,  Seeley.     Karoo  Formation  (Permian  or  Trias) ;  Tambor  Fontein,  Cape  Colony. 

Skeleton  ;  1/20  (after  Seeley). 

placed.  Occipital  condyle  slightly  indented.  Bones  of  the  palate  fused,  and 
bearing  several  series  of  small  teeth.  There  are  aboiit  eighteen  presacral 
vertebrae,  each  with  a  deepened  articulation  for  the  single-headed  ribs. 
Small  intercentra  occur  between  all  the  dorsal  vertebrae;  the  four  sacrals 
are  not  fused.  About  thirty  caudal  vertebrae,  the  anterior  ones  with  short 
ribs,  and  nearly  all  with  neural  arches  and  chevron  bones.  Scapula  very 
long,  like  that  of  Dinosaurs.  Coracoid  small  and  subrectangular,  epicoracoid 
narrow  and  triangulär ;  clavicles  robust,  meeting  in  the  middle  line  and  resting 
on  the  front  border  of  the  large  T-shaped  interclavicle.  A  supraclavicle  also 
Said  to  be  present  on  each  side.     Humerus  short,  massive,  expanded  at  the 


ORDER  V 


THEROMORPHA 


181 


ends  ;  epicondylar  forameii  not  observed.  Ulna  very  stout,  with  prominent 
olecranon  process.  Pelvic  bones  massive,  coössified ;  acetabulum  closed. 
Hind  limb  slightly  shorter  than  the  fore,  and  digits  rather  smaller ;  the  five 
ungual  phalanges  clawed.      P.  bombifrons,  F.  serridens,  Owen ;  F.  baini,  Seeley. 

?  Tapinocephalus,  Anthodon,  Owen.     Karoo  Formation  ;  South  Africa. 

Elginia,  Newton.  Known  only  by  the  skull,  which  is  about  15  cm.  long, 
triangulär,  coarsely  sculptured,  and  provided  with  a  number  of  paired  bosses 
and  spinous  or  horn-like  defences.  These  occur  along  the  posterior  and  lateral 
margins,  and  on  the  parietal,  frontal,  and  nasal  Clements.  Teeth  with  slightly 
constricted  base  and  serrated  crowns.     Supposed  Trias  of  Elgin,  Scotland. 

Frocolophon,  Owen  (Fig.  285).  Skull  about  5  cm.  long,  short  and  tri- 
angulär, not   externally  sculptured.      Orbits  greatly  enlarged,  and    temporal 


9^^      P 


Fig.  285. 


Frocolophon  trigoniceps,  Owen.  Karoo  Formation  (Permian  or  Trias) ;  South  Africa.  Restoration  of  skull 
from  suijerior  (A),  inferior  (J5),  and  lateral  (C)  aspect^,  also  part  of  the  pectoral  arch,  slightly  reduced.  ac, 
Glenoid  cavity  for  humerus  ;  bs,  Basisphenoid ;  co,  Coracoid  ;  ecpt,  Ectopterygoid ;  epco,-  Epicoracoid ;  /, 
Frontal ;  icl,  Interclavicle  ;  ipt,  Interpterygoid  vacuity  ;  j,  Jugal ;  l,  Lachrynial ;  Itf,  Lateral  temporal  vacuity  ; 
md,  Mandible  ;  mx,  Maxilla  ;  na,  Nasal ;  nar,  Anterior  nares  ;  orb,  Orbit ;  p,  Down  ward  ectopterygoid  process  ; 
pa,  Parietal ;  pin,  Pineal  foranien  ;  pl,  Palatine  ;  pmx,  Premaxilla  ;  prf,  Prefrontal ;  pt,  Pterygoid  ;  ptna.  Pos- 
terior nares  ;  ptf,  Postfrontal ;  pto,  Postorbital ;  (jj,  Quadrato-jugal ;  qu,  Quadrate  ;  st,  Suprat«niporal  or  pro- 
sqnamosal ;  sq,  Squamosal ;  v,  Vomer  (from  A.  S.  Woodward). 

arcade  pierced  by  a  slight  vacuity.  Teeth  conical ;  a  series  of  minute  teeth 
present  on  vomer  and  pterygoids.  Interclavicle  T-shaped,  with  elongated 
arms  ;  epicoracoid  notched.     Karoo  Formation ;  South  Africa. 

Aristodesmus,  Seeley.  Lower  Trias;  Switzerland.  ? Fhanerosmirus,v.  Meyer. 
Permian ;  Saxony. 

Family  2.     Pariotichidae.     Cope. 

Teeth  in  more  than  one  series  in  one  or  both  jaws,  and  with  cylindric  roots ; 
vertebrae  ossified.     Permian. 

Ofocoelus,  Cope.  Skull  about  12  cm.  long,  externally  sculptured,  but 
without  bosses.      Dorsal  carapace  consisting  of  a  series  of  twelve  or  more 


182 


REPTILIA 


CLASS  III 


transversely  elongated  bands  of  bone  alternating  with  the  ribs.     Permian  ; 
Texas.     0.  testudineus,  Cope. 

Pariotichus  (Edoci/nodori),  Isodecfes,  Pantylus,  Hi/popnous,  Cope.     Texas. 


Family  3.     Diadectidae.     Cope. 

Anterior  teeth  oUusely  conical,  the  other  marginal  teeth  laterally  expanded,  with 
tumid  bases  and  inner  and  outer  cusps  of  unequal  height.  Vomer  with  minufe  teeth. 
Basioccipital  loosely  articulated.     Permian. 

PJmpedias,  Cope  {Empedocles,  Cope).  Skull  triangulär,  50  cm.  long.  Sacrum 
of  two  vertebrae  ;  pelvic  bones  fused.     Permian  ;  Texas. 

Diadedes,  Chilonyx,  Bolboden,  Cope.     Permian ;  Texas. 


Sub-Order  2.     THERIODONTA.     Owen.     {Cynodontia,  Owen.) 

Investing  bones  of  temporal  region  contracting  into  a  Single  broad  arcade,  sometimes 
irregularly  perforated  ;  supratemporal  vacuity  large,  quadrate  small.  External  bones 
not  sculptured.  Occipital  condyle  bilobate ;  premaxillae  separate;  marginal  teeth 
differentiated  into  incisors,  canines,  and  molars.  External  nares  terminal,  separate, 
or  undivided;  internal  openings  displaced  backwards,  owing  to  development  of  secondary 


The  skull  of  Theriodonts   is  remarkably  similar  in   form  to  that  of  car- 

nivorous  mammals,  and  the 
dentition  exhibits  modifica- 
tions  unusual  among  reptiles. 
The  mandible  bites  within  the 
Upper  jaw,  and  the  lower 
canines  cross  in  front  of  the 
Upper  as  in  mammals.  Owing 
to  the  development  of  a 
secondary  or  false  palate  by 
plates  from  the  maxillae  and 
palatines,  the  opening  of  the 
internal  nares  on  the  roof  of 
the  mouth  is  displaced  back- 
ward, as  in  crocodiles  and 
mammals.  An  approach  to 
the  dicondylic  condition  of 
the  mammalian  skull  is  also 
frequently  observed.  The 
skeleton  of  the  trunk  and 
limbs  is  imperfectly  known. 


c,^^ 


Bo  Pa 


Fig.  28(3. 


Galesaunis  planiceps,  Owen.  Karoo  Forniatioii ;  Basiitolaiid. 
South  Africa.  Skull,  slightly  restored,  from  lateral  (A),  palatal 
(B),  and  superior  (C)  aspects,  i/o.  1),  Posterior  tooth,  enlarged. 
a,  Orbit ;  bo,  basioccipital ;  ch,  Posterior  nares  ;  Jr,  Frontal ;  md, 
Mandible  ;  mx,  Maxilla  ;  N,  Anterior  narial  opening  ;  na,  Nasal ; 
JM,  Parietal ;  prf,  Prefrontal ;  pt,  Pterygoid  (after  Owen). 

openings  confluent  or  separated  ;  limb  bones  slender. 

Galesaurus,  Owen  (Nythosaurus,  Owen),  (Fig.  286) 


Family  1.     Galesauridae. 

Lydekker. 

Palatal    teeth    insignificant 
or    wanting ;     external     narial 
Trias. 

Know^n  only  by   the 


ORDER  V 


THEROMORPHA 


183 


skull,  which  is  less  than  10  cm.  long,  and  has  the  nares  divided  by  a  median 
septum.  Four  incisors  above  and  three  below,  with  one  canine  and  a  number 
of  tricuspidate  molars  in  each  jaw.      Karoo  Formation ;  South  Africa. 

Djcosaurus,  Owen  (Fig.  287).  Like  the  preceding,  except  that  the  molari- 
form  teeth  are  all  simple  cones,  though  more  or  less  compressed  and  with  finely 
serrated  edges.  There  are  about 
five  of  them  on  each  side  above 
and  below.  Karoo  Formation  ; 
South  Africa. 

Aelurosaurus,  Owen.  Difters 
from  Lycosaurus  in  having  small, 
pointed  teeth  irregulär ly  grouped 
on  anterior  half  of  the  palate. 
Same  horizon. 

Cynognathus,  Seeley.  Skull 
remarkably  mammalian  -  like, 
about  40  cm.  long,  with  divided 
nares  and  two  prominent  convex 
condyles  below  the  foramen 
magnum,  composed  chiefly  of 
the  exoccipitals.  There 
four  serrated  incisors  in  the 
Upper  and  three  in  the  lower  jaw  ;  and  one  canine  and  nine  molars  above 
and  below  on  each  side.  Six  cervicals,  eighteen  dorsals,  five  lumbars,  and 
three  or  four  sacrals.     Accompanies  the  preceding.     C.  crateronoius,  Seeley. 

Cipiochampsa,  Cynodraco,  Cynosuchus,  Gorgonops,  Tigrisuchus,  Owen.     Founded 
on  more  or  less  imperfect  remains  from  the  Karoo  Formation  of  South  Africa. 


Fig.  287. 
Lycosaunis  curvimola,  Owen.     Karoo  Formation ;  Kugaberg, 
„„^    Cape  Colony.     Skull,  lateral  aspect,  i/s-     «>  Orbit;  b,  Mandible 
"^^^    (after  Owen). 


Family  2.     Deuterosauridae.     Seeley. 

Canines  large,  with  serrated  anterior  and  posterkrr  margins ;  no  palatal  teeth. 
Sacrum  of  two  anchylo^ed  vertehrae.  Rihs  double-headed.  Scapula  flat ;  ilium  not 
produced  anteriorly  ;  acetabulum  dosed.     Permian  ;  Kussia. 

Deuterosaurtis,  Eichw.  Skull  with  a  median  crest ;  incisors  large  and 
transversely  compressed.  Lachrymals  greatly  developed ;  quadrate  large; 
scapula  distally  expanded. 

Rhopalodon,  Fischer.  Like  the  preceding,  but  with  serrated  incisors,  and 
lanceolate  molars  behind  the  canines.  Supratemporal  vacuity  very  small; 
sclerotic  ring  present. 

The  fragmentary  remains  described  as  Brithopus,  Orthopus,  and  Syodoii  by 
Kutorga,  and  Dinosaurus  by  Fischer,  are  probably  identifiable  with  the  above 
genera,  which  they  accompany.  Cliorhizodou,  Twelvetrees,  is  of  uneertain 
Position. 

Family  3.     Tritylodontidae.     Cope. 

Snout  hroad  and  ohtuse.  Ä  fair  of  large  incisors  or  canine-like  teeth  in  front, 
apparently  growing  from  a  persistent  pulp.  Molariform  teeth  bearing  two  or  three 
longitudinai  series  of  tuberdes.  Posterior  nares  remote,  and  roofed  over  by  secondary 
palate.     Quadrate  reduced.     Trias. 


184 


REPTILIA 


CLASS  III 


This  family  is  regarded  by  Seeley  as  typical  of  a  distinct  order  of  reptiles, 
Gomphodontia,  and  ancestral  to  mammals. 

Tritylodon,  Owen  (Fig.  288).     Known  by  small,  decidedly  mammalian-like 

crania.  Karoo 
Formation;  South 
Africa. 

Gomphognathus, 
Diademodon,  Mi- 
crogomj)hodon,  Tri- 
rachodon,  Seeley. 
The  first-named 
has  a  double 
occipital  condyle, 


Fig.  288. 

Tritylodon  longaevus,  Owen.     Trias  ;  Taba-chow,  Basutoland,  South  Africa. 
Skull  from  superior  and  palatal  aspects,  '-2/3  (after  Owen). 


Fig.  289. 

Triglyplius  fraasi, 
Lyd.  Upper  Trias ; 
Hohenheim,  Würteni- 
berg.  Upper  molar. 
1/1  and  2/1  (after  Fraas). 


and  its  single  zygomatic  arch  resembles  that  of  mammals.  Theriodesmus, 
Seeley,  is  known  by  a  remarkably  mammalian-like  fore-limb  and  manus. 
Karoo  Formation  ;  South  Africa. 

Triglyphus,  Fraas  (Fig.  289).     Known  only  by  minute  teeth  from  the  Upper 
Triassic  Bone-bed  of  Hohenheim,  near  Stuttgart. 


Sub-Order  3.     ANOMÖDONTIA.     Owen.     (Dicynodontia ,  Owen.) 

Investing  hones  of  temporal  region  contracting  into  a  single  broad  arcade,  formed 
principally  by  the  enormously  developed  squamosal.  External  bones  not  sculptured ; 
supratempoi^al  vacuity  large ;  quadrate  small;  premaxillae  fused;  external  nares 
separated.  Jaws  edentulous,  or  with  a  single  pair  of  tusk-like  teeth  in  the  maxillae 
set  in  deep  alveoli  and  growing  from  persistent  pulps.  Cervical  ribs  double-headed, 
dorsal  single-headed,     Sacrum  of  five  or  six  vertebrae. 

The  Anomodonts  or  Dicynodonts  are  mostly  large  terrestrial  reptiles  of 
Triassic  age,  of  which  no  complete  skeletons  have  yet  been  discovered,  but 
numerous  crania,  vertebrae,  and  other  fragments  are  known  from  South  Africa, 
East  India,  Ural,  and  Scotland. 

The  vertebral  column  consists  of  seven  or  eight  cervical,  twelve  or  thirteen 
dorsal,  five  or  six  sacral,  and  about  twenty  caudal  vertebrae.  The  centra  are 
short  and  slightly  amphicoelous.  Double-headed  ribs  are  borne  by  the  cervical, 
and  single-headed  ribs  by  the  dorsal  vertebrae.  The  cranial  sutures  (Fig.  290) 
are  frequently  obscure  and  difficult  to  determine.  The  brain  cavity  is  very 
small  and  the  surfaces  for  attachment  of  the  muscles  of  the  jaw  unusually 
large.  On  either  side  of  the  upright  occiput  is  an  enormously  developed 
squamosal,  which  forms  the  greater  part  of  the  single  temporal  arcade,  and  is 


ORDER  V 


THEKOMORPHA 


185 


fused  with  the  small  quadrate  below.  A  foramen  is  enclosed  by  the  parietals, 
which  are  small,  and  sometimes  much  reduced.  The  frontal  and  prefrontal 
form  the  superior  border  of  the  orbit,  and  the  maxilla,  lachrymal,  and  pre- 
frontal the  anterior.  The  orbits  are  laterally  placed  in  about  the  middle  of 
the  skull,  and  in  one  genus  (Ptychognathus)  traces  of  a  sclerotic  ring  have  been 
observed.  A  narrow,  curved  bar,  the 
postorbital,  separates  the  orbit  from 
the  supratemporal  vacuity,  and  the 
lower  orbital  boundary  is  formed  by 
the  maxilla  together  with  a  very 
massive  jugal. 

The  nasals  are  steeply  inclined 
toward  the  front,  and  form  with  the 
unpaired  premaxilla  a  sometimes  elon- 
gated  rostrum.  Small  internasals  are 
occasionally  present  below  the  anterior 
nares,  which  are  placed  laterally  at  the 
junction  of  the  nasals,  lachrymals,  and 
premaxillae.     The  oral  border  of  the 


Fig.  290. 
Ptvchognathn.<<  dedims,  Owen.     Karoo  Formation;  Rhenosterberge,  Cape  Colony.     Skull  from  lateral  {A) 
superior  (B),  and  posterior  (C)  aspects,  1/3.     A,  Orbit;  ang,  Angular ;  bo,  Basioccipital ;  e,  MaxUlary  tusk ;  a 
Dentary ;  exo,  Exoccipital ;  fr,  Frontal;  j«,  Jugal;  mx,  Maxilla;  N,  External  narial  opemng-    -'- 
Parietal ;  jw/ia;,  Premaxilla  ;  prf,  Prefrontal ;  pf/,  Postfrontal ;  qu,  Quadrate 
(after  Owen).  | 


na,  Nasal ;  pa, 
Supraoccipital ;  sq,  Squamosal 


latter  forms  a  sharp,  cutting  edge,  and  was  probably  sheathed  during  life  of 
the  animal  by  a  corneous  layer,  as  in  Chelonians  and  Aves.  A  pair  of 
powerful,  decurved,  tusk-like  teeth,  one  on  each  side,  is  deyeloped  by  the 
maxillae,  and  the  deep  alveoli  in  which  they  are  seated  are  indicated  by  an 
external  folding  of  the  plate.  Even  among  toothless  forms  alveoli  are  present, 
but  are  occupied  by  osseous  substance. 

The  basioccipital  is  short  and  takes  part  in  the  occipital  condyle.  In  front 
of  it  on  the  lower  side  (Fig.  291)  is  placed  a  subrectangular  basisphenoid  which 
joins  the  very  large  pterygoids.  The  latter  meet  in  the  middle  line,  but  leave 
a  small  interpterygoidal  vacuity  behind  the  narrow  vomer.     The  backwardly 


186 


EEPTILTA 


CLASS  III 


directed  internal  nares  are  scarcely  if  at  all  covered  by  a  secondary  develop- 
raent  of  the  palatine  plates.  The  mandible  is  without  a  coronoid  process,  and 
the  rami  are  fused  at  the  Symphysis.  Their  oral 
borders  are  sharp,  and  were  probably  once  encased 
in  hörn. 


Pmx 


Fig.  291. 

Dieytiodon  pardic&ps,  Owen.  Karoo  Formation  ;  Fort  Beaufort,  Cape 
Colony.  Palatal  aspect  of  skull,  1/4.  ho,  Basioccipital ;  c,  Maxillary  tusk 
(fractured) ;  ju,  Jugal ;  mx,  Maxiila ;  'pmx,  Preraaxilla ;  pl,  Palatine ;  pf, 
Pterygoid  ;  (ju,  Quadrate  (after  Owen). 


Fig.  292. 

Dicynodon  pardiceps,  Owen. 
Anterior  aspect  of  hnmerus,  1/4- 
b,  Delto-pectoralridge  ;  c,  Entepi- 
condylar  foranien  (after  Owen). 


The  scapula  is  a  very  long  bone,  similar  to  that  of  Monotreme  mammals. 
It  bears  an  acromial  process  and  is  attached  by  its  proximal  end  to  the  cora- 
coid  and  epicoracoid.  The  humerus 
is  short  and  excessively  stout,  with 
an    entepicondylar    foramen ;    ulna 


Etirycnrpus  oivcni,  Seeley.  Karoo 
Formation  ;  Schneebergkette,  Cape 
Colony.  Left  fore-limb  with  Impression 
of  dermal  covering,  1/3  (after  Owen). 


Fig.  294. 
Flatupodosaurus  robnstus,  Owen.  Karoo  Forma- 
tion ;  Cape  Colony.  Ventral  aspect  of  sacrum  and 
right  half  of  pelvis.  ü,  Ilium ;  isch,  Ischium  ; 
0,  Obturator  foramen;  pu,  Pubis ;  .  si— §5,  Sacral 
vertebrae.  ^.J 


and  radius  are  separated.     In  the  pelvic  arch  the  three  elements  of  each  side 
are   fused    into   an    innominate    bone    which    joins    its    fellow    in   a   median 


THEROMORPHA  187 

Symphysis.  The  femur  and  crus  are  somewhat  longer  than  the  corresponding 
bones  of  the  fore-limb. 

Dicißiodon,  Owen  (Figs.  291,  292).  Skull  attaining  a  length  of  0*5  m. 
Transition  from  parieto-frontal  to  nasal  region  gradual ;  maxillae  with  a  pair 
of  tusk-like  teeth.  Abundant  and  represented  by  over  a  dozen  species  in  the 
Karoo  Formation  of  South  Africa. 

Oudenodon,  Owen.  Like  the  preceding,  but  toothless;  possibly  referable 
to  females  of  Dicynodon. 

Ptycliognatlms,  Owen  {Lystrosaurus,  Cope),  (Fig.  290).  Frontal  and  nasal 
regions  sloping  at  a  sharp  angle  from  top  of  the  skull.  Smaller  than 
Dicynodon,  which  it  accompanies. 

Gordonia,  Newton.  Form  of  skull  similar  to  Dicynodon,  but  much  smaller, 
with  more  delicate  bones  and  diminutive  teeth;  premaxilla  nearly  vertical. 
Supposed  Trias  of  Elgin,  Scotland. 

Geikia,  Newton.     Resembling  Ftychognathus,  but  toothless.     Elgin  Trias. 

Eurycarpus,  Seeley  (Fig.  293);  Keirognathus,  Seeley  ;  Theriognathiis,  Tifano- 
suchus,  Platypodosaurus  (Fig.  294),  Owen.  All  founded  on  fragmentary  remains 
from  the  Karoo  Formation  of  South  Africa. 


Sub-Order  4.     PLACODONTIA.     von  Meyer.i 

Bones  of  temporal  region  forming  a  Single  hroad  arcade  ;  sup'atemporal  vacuity 
large,  opening  superiorly ;  orbits  and  external  .nares  laterally  placed ;  the  latter 
separate  and  remote.  Palate  with  a  paired  longitvdinal  series  of  pavement  teeth,  and 
similar  ones  present  in  single  series  on  the  dentary.  Anterior  teeth  ahove  and  helow 
cylindro-conical ;  maxillae  with  a  series  of  depressed,  conical,  or  molarifmin  teeth. 

Placodonts  are  remarkable  for  their  peculiarly  modified  dentition,  which  is 
unparalleled  among  reptiles.  The  pavement-like  crushing  teeth  of  the  palate 
and  lower  jaw  attain  considerable  size,  and  exhibit  flat  or  slightly  arched 
crowns,  usually  dark-coloured,  and  smooth  or  finely  wrinkled.  They  are 
replaced  by  successional  teeth  developed  beneath  them. 

The  skull  is  similar  in  form  to  that  of  Dicynodonts  and  certain  Therio 
donts ;  and  as  in  these  groups  the  temporal  and  jugal  arches  unite  to  form  a 
Single,  broad,  bony  arch  across  the  postero-lateral  region  of  the  cranium.  The 
quadrate  is  fused  with  the  squamosal  and  jugal,  and  exposes  a  prominent 
transverse  condyle.  On  the  under  side  the  palatines  and  pterygoids  unite  to 
form  an  extensive  bony  palate  for  the  support  of  the  pavement  teeth.  The 
internal  nares  are  placed  far  forwards,  but  the  external  openings  and  orbits 
occupy  similar  positions  to  those  in  Dicynodon.  Of  the  rest  of  the  skeleton 
nothing  is  known.  The  detached  teeth  were  for  a  long  time  confounded  with 
iishes,  until  their  reptilian  nature  was  demonstrated  by  Owen.  All  the 
remains  are  from  the  marine  Trias  of  central  Europe. 

Placodus,  Agassiz  (Figs.  295,  296).  Skull  not  much  longer  than  broad, 
superiorly  arched,  the  snout  somewhat  produced.  Premaxillae  and  Symphysis 
of  lower  jaw  with  cylindro-conical  incisors.     On  either  side  of  the  palate  and 

^  Literature :  ri-  j       i 

Mei/er,  H.  von,  Unterkiefer  von  Placodus  andriani  (Palaeoutogr.  vol.  X.  p.  59),  1862.— IökL  vol. 
XI.  1863. — Mänster,  O.  von,  Ueber  einige  ausgezeichnete  fossile  Fischzähne  aus  dem  Muschelkalk 
bei  Bayreuth.  1830.— Ueber  Placodus  rostratus  (Beiträge  zur  Petrefaktenkunde,  pt.  4),  1843.— 
ihren,  R.,  Description  of  the  skull  and  teeth  of  Placodus  laticeps  (Phil.  Trans,  vol.  XLIX.),  1858. 


188 


KEPTILIA 


CLASS  III 


011  the  dentary  are  three  large  rectangular  pavement  teeth ;  maxillae  with  a 
Single  series  of  depressed,  conical  teeth.  Detached  teeth  are  abundant  in  the 
Muschelkalk  of  Southern  Germany  and  France,  rare  in  the  Wellendolomite 
and  Alpine  Keupei 

Cyamodus,  v.  Meyer.     Skull  triangulär,  snout  much  compressed.     Supra- 
temporal vacuity  elongated  oval,  nearly  three  times  as   large  as   the  orbits, 


Placodus  gigo^,  Ag.  Muschelkalk ;  Bayreuth, 
Germany.  A,  Palatal,  and  B,  superior  aspects  of 
skull,  1/3.  C,  Oral,  and  7),  lateral  aspects  of  man- 
dible,  1/3- 


Fig.  296. 

Placodus  hypsiceps,  v.  Meyer.  Muschelkalk  ;  Bayreuth,  Germany. 
Lateral  aspect  of  skull,  1/3.  A,  Orbit ;  N,  Externa]  narial  opening 
(after  von  Meyer). 


which  are  placed  in  anterior  third  of  the  skull.  Anterior  nares  small, 
separate,  nearly  terminal.  On  either  side  of  the  palate  are  placed  two  or 
three  rounded  or  elliptical-crushing  teeth,  the  hindmost  at  least  twice  the  size 
of  the  anterior.     Muschelkalk  ;  Bavaria.      C.  rostratus,  Münster  sp. 


ORDER  VI 


CHELONIA 
Range  and  Distribution  of  the  Theromorpha. 


189 


Divisions. 

Permian. 

Trias. 

Europe. 

N.  America. 

Europe.    ' 

S.  Africa. 

I.  Pareiasaijkia. 

1.  Pareiasauridae   . 

2.  Pariotichidae 

3.  Diadectidae          .         .         . 

IL  Theriodontia. 

1.  Galesauridae 

2.  Deuterosauridae 

3.  Tritylodontidae  . 

III.  Anomodontia 
lY.  Placodontia 

(Ural  ?) 

1 

1 


Order  6.     CHELONIA.     {Testudinata.) 


Beptiles  of  stout  and  wide  form  of  hody,  encased  in  a  more  or  less  compleU 
hony  shell.  Quadrate  immovahly  united  to  the  cranial  arches.  Jaws  toothless,  but 
covered  with  horny  sheaths  ;  premaxillae  very  small,  jpalate  completely  closed  by  jiinction 

^  Literature  : 

Banr,  G.,  Osteologische  Notizen  über  Keptilien  (Zool.  Anz.  vol.  IX,  No.  238),  1886. — Ibid. 
vol.  XI.  (1888),  pp.  417,  592  ;  and  vol.  XII.  (1889),  p.  40.— Notes  on  some  little  knovvn  American 
fossil  Tortoises  (Proc.  Acad.  Nat.  Sei.  Philadelphia,  p.  411),  1891. — ^Bemerkungen  über  die  Phylo- 
genie  der  Schildkröten  (Anat.  Anz.  vol.  XII.  p.  561),  ]896. — Bovlenger,  G.  A.,  Catalogue  of 
Chelonians  in  the  British  Museum.  London,  1889. — Gase,  E.  C,  On  the  osteology  and  relationships 
of  Protostega  (Journ.  Morph,  vol.  XIV.  No.  1),  1897.— Cojjß,  E.  D.,  The  Reptiles  of  the  American 
Eocene  (Amer.  Nat.  vol.  XVI.  p.  979),  l%%2.—IUd.  vol.  XXX.  p.  398,  \%^Q.—Dames,  ir.,  Die 
Chelonier  der  norddeutschen  Tertiärformation  (Palaeont.  Abhandl.  Dames  und  Kayser,  vol.  VI.), 
1894. — Dollo,  L.,  Note  sur  les  Cheloniens  de  Bernissart  (Bull.  Mus.  Roy.  d'Hist.  Nat.  Belg.  vol.  III. 
p.  63),  1884  ;  ibid.  vol.  IV.  (1886),  pp.  69,  129  ;  and  ibid.  vol.  V.  (1888),  p.  59.— On  the  humerus 
of  Euclastes  (Geol.  Mag.  [3],  vol.  V.  No.  6),  1888. — Fraas,  E.,  Proganochelys  Quenstedtii  Baur 
(Jahresh.  Vereins  Naturk.  Würtb.),  1899.  —  Gray,  J.  E.,  Notes  on  the  families  and  genera  of 
Tortoises  (Pi'oc.  Zool.  Soc.  vol.  XII.  p.  165),  1869. — Hoffmann,  G.  K.,  Chelouia,  in  Bronn's  Classeu 
und  Ordnungen  des  Thierreichs,  vol.  VI,  1879. — Lydekker,  R.,  Siwalik  and  Narbada  Chelonia 
(Palaeont.  Indica,  ser.  X.  vol.  IIL),  1886. — Catalogue  of  the  fossil  Reptilia  and  Amphibia  in  the 
British  Museum,  Part  III.  London,  1889. — Maack,  G.  A.,  Die  bis  jetzt  bekannten  fossilen  Schild- 
kröten, etc.  (Palaeontogr.  vol.  XVIIL),  1869. — Meyer,  H.  von.  Zur  Fauna  der  Vorwelt,  Parts  I.  and 
IV.  Frankfort,  1845-60. — Owen,  R.,  and  Bell,  R.,  Monograph  of  the  fossil  Reptilia  of  the  London 
Clay,  Part  I.  (Palaeont,  Soc),  1851. — Owen,  R.,  Monograph  of  the  fossil  Cheloniau  Reptilia,  etc., 
ibid.  1852-53. — Pictet,  F.  J.,  and  Humbert,  A.,  Monographie  des  Cheloniens  de  la  Molasse  Suisse. 
Geneva,  1856, — Portis,  A.,  Ueber  fossile  Schildkröten  aus  dem  Kimmeridge  von  Hauover  (Palaeontogr. 
vol,  XXV,),  1878. — Les  Cheloniens  de  la  Molasse  Vaudoise  (Mem,  Soc.  Palaeont.  Suisse,  vol.  IX.), 
1882.  —  Reinach,  A.  v.,  Schildkrötenreste  im  Mainzer  Tertiärbecken,  etc.  (Abhandl.  Senckenb. 
naturf.  Ges.  vol.  XXVIII. ),  1900. — Rütimeyer,  L.,  Die  fossilen  Schildkröten  von  Soluthurn  (Denkschr. 
Schweiz,  naturf.  Gesellsch.  vol.  XXII.),  1867;  and  ibid.  vol.  XXV.  (1873).— Ueber  den  Bau  von 
Schale  und  Schädel  bei  lebenden  und  fossilen  Schildkröten  (Verhandl.  naturf.  Gesellsch.  Basel,  vol. 
III.  p.  255),  1872. — Sacco,  F.,  Cheloni  Astiani  del  Piemonte  (Mem.  Acad.  Torino,  vol.  XXXIX.), 
1889, —  Wagner,  J.  A.,  Schildkröten  und  Saurier  aus  den  lithographischen  Schiefer  (Abhandl.  bayer. 
Akad,  Wissensch.  IL  Classe,  vol,  VII.  p,  291),  1853  ;  and  ibid.  vol,  IX,  (1861),  p,  68.—  Wiehmd, 
G.  R.,  On  Archeion  ischyros,  Protostega,  etc.  (Amer.  Journ,  Sei,  [4],  vol,  IL  p.  399),  1896  ;  and 
ibid.  vol.  V,  (1898),  p.  15.— Williston,  S.  W.,  A  new  turtle  froni  the  Kansas  Cretaeeous  (lYans, 
Kans,  Acad.  Sei.  vol.  XVII,  p,  195),  1901. 


190  REPTILIA  CLASSiii 

of  the  pterygoids  with  the  basisphenoid,  and  frequenÜy  also  with  one  another.  Narial 
openiiig  single  and  terminal.  No  sternum  ;  ribs  single-headed  ;  two  sacral  vertebrae. 
Pubes  and  ischia  forming  symphyses.  Humerus  without  entepicondylar  foramoi. 
Pentadactyle  Walking  limbs  or  paddles. 

Chelonians  form  an  extremely  homogeneous  and  narrowly  circumscribed 
group,  their  peculiar  Organisation  separating  them  widely  from  all  other 
reptiles,  and  their  origin  and  phylogeny  being  very  obscure.  A  relationship 
with  the  Triassic  Dicynodonts  is  perhaps  indicated  by  the  skull,  which  is 
strikingly  similar ;  and  certain  features  of  the  palate  and  pectoral  girdle  are 
suggestive  of  the  Sauropterygia,  Khynchocephalia,  and  Labyrinthodont  Stego- 
cephaliang.  Chelonians  first  make  their  appearance  in  the  Upper  Keuper  of 
Southern  Germany  (Proganochelys)  and  exhibit  all  the  typical  characters  of  the 
Order ;  nor  do  they  undergo  any  noteworthy  modifications  in  structure  during 
all  their  subsequent  history. 

Shell. — The  most  distinctive  character  of  the  group  is  the  investment  of 
the  body  in  a  more  or  less  rigid  shell  or  box,  which  is  composed  partly  of  the 
modified  neural  spines  of  the  dorsal  vertebrae,  and  partly  of  dermal  ossifica- 
tions  more  or  less  intimately  united  with  the  former.  Into  this  capsule  the 
limbs,  tail,  and  usually  also  the  neck  and  head  are  capable  of  being  retracted. 

In  most  forms  both  the  dorsal  shell  or  carapace,  and  the  ventral  or  plastron, 
are  superficially  covered  with  a  leathery  or  corneous  epidermal  layer,  which  is 
divided  by  indented  sutures  into  a  few  large  scutes  or  shields.  These  epi- 
dermal shields  are  arranged  quite  independently  of  the  subjacent  osseous  plates, 
and  are  wanting  only  in  Trionychoidea  and  Bermochelys.  They  afford  valuable 
diagnostic  characters  amongst  recent  forms,  but  as  a  rule  are  completely 
destroyed  by  the  fossilisation  process,  their  sutures  being  merely  indicated  by 
shallow  sulci.  On  the  carapace  they  form  a  median  dorsal  and  a  paired  lateral 
series,  there  being  usually  five  unpaired  or  vertebral  shields,  and  four  or  five 
pairs  of  costal  shields  (Figs.  305,  306).  Eound  the  periphery  there  is  also  a 
series  of  about  twenty-four  marginals  (marginalia),  the  anterior  of  which 
is  called  the  nuchal,  and  the  posterior,  sometimes  double,  the  caudal  or  "  supra- 
caudal "  shield.  Five  or  six  pairs  of  epidermal  shields  are  present  in  the 
plastron,  but  there  is  no  median  series.  The  anterior  pair  is  designated  as 
gulars,  following  which  in  the  order  named  are  the  humerals,  pectorals, 
abdominals,  femorals,  and  anals.  Occasionally  the  gulars  are  separated  in 
front  by  a  single  or  double  intergular  shield. 

The  osseous  plates  of  the  carapace  (Fig.  297)  are  formed  partly  by  lateral 
expansions  of  the  spinous  processes  of  eight  dorsal  vertebrae  (second  to  ninth), 
and  of  the  ribs  belonging  to  these  vertebrae ;  and  in  still  greater  part  by 
dermal  ossifications  overlying  the  ribs  and  joining  the  expanded  spinous 
processes  on  either  side  of  the  median  line.  The  plates  of  the  carapace  thus 
differ  in  number  and  arrangement  from  the  epidermal  shields,  inasmuch  as 
they  coincide  with  the  vertebrae  and  ribs.  The  latter  retain  their  individuality 
more  or  less  distinctly  on  the  visceral  side  of  the  costal  bones,  and  extend 
across  the  vacuities  when  the  carapace  is  incomplete. 

The  median  series  of  eight  bony  plates  in  the  carapace  are  called  neurals  or 
"  vertebrals  " ;  and  the  lateral  pieces  lying  superjacent  to  the  ribs,  which  are 
firmly  united  to  one  another  and  to  the  neurals  by  suture,  are  termed  pleurals 
(or  "  costals  ").  Sometimes  not  all  of  the  neural  bones  are  developed,  and  among 
the  recent  Pleurodira  of  Australia  they  are  wanting  altogether.     In  front  of 


R  VI 


CHELONIA 


191 


the  series  of  neural  plates  is  a  large  hexagonal  plate,  the  iiuchal,  which  is 
broader  than  long,  and  situated  above  the  first  dorsal  vertebra.  This  plate, 
which  is  present  in  all  Chelonians,  is  a  cartilage  bone,  develcped  simultaneously 
with  the  neurals,  and  has  been  supposed  to  represent  the  modified  ribs  of  the 
last  cervical.  Continuing  the  series  of  neurals  behind  are  two  to  four  un- 
paired  membrane  bones  termed  the  pygal  plates  or  "  postneurals,"  the  last  of 
which,  in  shape  and  position,  forms  part  of  the  peripheral  series.  In  addition 
to  the  posterior  azygous  peripheral  or  pygal,  there  are  eleven  (exceptionally 
twelve)  peripheral  plates  on  each  side,  except  in  Staurotypus  and  Cinosternum, 


Fig.  29 

CheloHc  midas,  Latr.  Receut ; 
Dorsal  aspect  of  carapace.  B, 
Ventral  asjiect  of  plastron.  ci— 
Entoplastron  ;  ep,  Ei^iplastron  ; 
kpp,  Hypoplastron ;  m,  Marginals 
spiiie  ;  iiti,  Nuchal ;  p,  Plastron ; 
r,  Ribs  ;  w,  Vertebral  centrum 
1 — 8,  Neural  plates,  followed  by 

pygal. 


Atlantic  Ocean.  A, 
Section  of  shell.  C, 
-c8,  Costal  plates  ;  e, 
hyp,  Hyoplastron  ; 
;  n,  Expanded  neural 
py,  First  suprapygal ; 
;  xp,  Xiphi  plastron  ; 
two  sui)rapygals  an( 


which  have  but  ten.  The  peripherals  and  pygals  owe  their  origin  entirely  to 
dermal  ossification. 

There  are  normally  eight  pairs  of  neural  plates,  but  some  fossil  marine 
forms  have  nine  or  ten.  The  first  neural  is  constantly  the  broadest,  the  last 
the  smallest ;  in  a  few  forms  these  plates  are  of  unequal  width,  alternately 
widening  proximally  and  narrowing  distally.  The  distal  extremity  of  the  rib 
persists  as  a  free  point  fitting  into  a  corresponding  socket  of  the  peripheral 
plate.  In  a  number  of  forms  there  are  persistent  fontanelles  or  vacuities 
between  the  neural  and  peripheral  plates,  and  also  in  the  plastron. 

The  plastron  arises  exclusively  from  dermal  ossification,  and  is  entirely 
independent  of  the  pectoral  arch,  with  which  it  has  sometimes  been  homo- 
logised.  It  consists  usually  of  nine  bones,  a  median  anterior  entoplastron  (or 
'' interclavicular "),  and  on  each  side  following  this  in  the  order  named,  an 
epiplastron,  a  hyoplastron,  a  hypoplastron,  and  a  xiphiplastron.  Some 
authors  have  regarded  the  epiplastra  as  equivalent  to  the  clavicles,  the 
entoplastron  to  the  interclavicle,  and  the  other  elements  as  modifications  of 


192  REPTILIA  class  in 

the  Stegocephalian  and  Rhynchocephalian  abdominal  ribs.  An  entoplastron 
is  wanting  among  the  Cinosternidae,  and  in  Baena  and  the  Pelomedusidae  the 
usual  number  of  nine  bones  is  increased  to  eleven,  the  additional  elements 
being  the  mesoplastra,  situated  between  the  hyo-  and  hypo-plastra.  The 
mesoplastra  may  have  served  in  the  primitive  condition  to  close  the  lateral 
vacuities.  Until  late  in  life  in  the  Chelydridae,  and  throughout  in  the  Chelo- 
nidae,  the  paired  abdominal  bones  are  separated  by  wide  fontanelles  (Fig. 
297,  C),  whilst  in  all  other  recent  Cryptodires  the  plastron  forms  in  the  adult 
a  solid  shell,  which  may  be  divided  into  two  or  three  portions  by  the  presence 
of  one  or  two  transverse  ligamentous  hinges,  as  in  Cistudo,  Emys,  etc. 

"  In  the  adult  of  most  genera  the  hyo-  and  hypo-plastra  are  united  with 
the  marginal  plates  by  suture ;  in  a  f ew  they  are  narrowly  separated  from  the 
latter  by  ligament,  or  the  outer  border  of  these  bones  form  digitate  dentations, 
which  may  either  articulate  by  gomphosis  with  the  marginals  or  be  entirely  free. 
The  Space  between  the  body  of  the  plastron  and  the  marginals  is  called  the 
bridge ;  it  is  particularly  short  or  absent  in  those  Testudinidae  in  which  the 
plastron  is  movable,  and  long  and  narrow  in  those  forms  (Chelydridae)  in  which 
the  plastron  is  particularly  small,  the  whole  shield  being  cruciform.  In  such 
Testudinidae  as  have  the  plastron  suturally  united  with  the  carapace,  the  hyo- 
and  hypo-plastron  each  sends  up  a  process,  respectively  termed  the  axillary  and 
inguinal  buttress,  which  anchylose  either  with  the  inner  surface  of  the  marginals 
or  with  the  costals ;  these  buttresses  are  least  developed  in  the  land  tortoises 
and  most  of  the  Testudinidae  frequenting  deep  water,  in  which  genera  they 
form  very  large  septa,  nearly  reaching  the  vertebral  region  and  forming  two 
lateral  Chambers  occupied  by  the  lungs  "  (Boulenger). 

Vertebral  column. — The  cervical  region  is  extremely  flexible,  and  comprises 
eight  non-costiferous  vertebrae,  the  first  of  which  is  biconcave,  and  the  last 
biconvex.  Transverse  processes  are  absent  or  extremely  rudimentary  in  this 
region.  The  ten  rib-bearing  dorsal  vertebrae  are  immovably  united  wüth  one 
another  and  with  the  carapace,  following  which  are  two  amphiplatyan  sacral 
vertebrae.  The  sacral  ribs  are,  as  on  the  last  dorsal  vertebra,  suturally 
united  w^ith  both  centrum  and  neural  arch ;  the  first  is  the  most  developed, 
and  considerably  expanded  distally.  The  caudal  vertebrae  ränge  in  number 
between  sixteen  and  thirty-five,  the  more  usual  number  being  from  twenty  to 
twenty-five.  The  centra  are  in  most  cases  procoelous,  but  sometimes  opistho- 
coelous.  Transverse  processes  or  costoids  are  present  on  most  of  the  vertebrae, 
and  connected  with  the  centrum  and  the  arch.  Neural  spines  are  not  developed, 
and  chevron  bones  are  absent  or  vestigial. 

Skull. — The  bones  of  the  skull  form  a  broad,  often  very  convex  roof,  which 
is  prolonged  posteriorly  in  a  strongly  developed  supraoccipital  crest.  The 
Orbits  are  large  and  placed  laterally  in  advance  of  the  middle  of  the  skull ;  the 
deeper  the  skull,  the  larger  the  orbits.  The  latter  are  completely  encircled  by 
four  or  five  bones — the  maxilla,  prefrontal,  sometimes  the  frontal,  the  post- 
frontal, and  the  jugal.  The  external  nostril  is  single  and  terminal,  bounded 
by  the  premaxillae,  maxillae,  and  prefrontals  or  nasals.  The  parietals  are  of 
large  size  and  distinct,  being  connected  with  the  palate  (except  in  the  Dermo- 
chelyidae)  by  descending  processes.  An  independent  lachrymal  bone  is  never 
present,  and  nasals  occur  only  rarely  among  the  Pleurodira  and  some  Cryptodira. 
The  anterior  margin  of  the  snout  is  formed  by  the  small,  usually  distinct 
premaxillae. 


ORDER  VI 


CHELONIA 


193 


The  postfrontals  are  large  in  most  Ciyptodires,  forming  a  postorbital 
arch ;  in  the  marine  turtles  the  postfrontal  unites  in  a  long  suture  with  the 
parietal,  the  whole  or  greater  part  of  the  temporal  region  being  roofed  over  by 
bone.  The  temporal  roof  attains  its  greatest  development  in  the  Chelonidae, 
where  three  cranial  arches  are  present — the  postfronto-squamosal,  the  jugo- 
quadratojugal,  and  the  parieto-squamosal.  In  all  other  Cryptodires  the 
parietal  is  widely  separated  from  the  squamosal,  and  as  a  rule  the  squamosal 
is  separated  from  the  postfrontal.  In  a  few  genera  there  is  no  bony  temporal 
arch,  and  the  quadrato-jugal  is  rudimentary  or  absent.  The  }ugal,  when 
present,  takes  part  with  the  maxilla  in  the  lower  border  of  the  orbit,  being 
excluded  from  it  only  in  the  genus  Platysternum.     The  proötic  and  opisthotic 


CluJ 


aiiJ 


Fig.  298. 

Trionyx  ganqeticus,  Cuvier.  Recent ;  India.  Superior  {A),  and  palatal  {B)  aspects  of  skull,  reduced, 
ho,  Basioccipital ;  hsph,  Basisphenoid  ;  ch.  Internal  nares  ;  exo,  Exoccipital ;  fr.  Frontal ;  j,  Jugal ;  inx,  Maxilla  ; 
JV,  External  nostril ;  op,  Opisthotic  ;  pa,  Parietal ;  pl,  Palatine  ;  pmx,  Premaxilla  ;  prf,  Prefrontal  +  nasal ;  pro, 
Proötic  ;  ptf,  Postfrontal ;  q,  Quadrate  ;  quj,  Quadrato-jugal ;  .S",  Supratemporal  fossa  ;  so,  Supraoccipital ;  sq, 
Squamosal ;  vo,  Vomer. 

are  both  stout  plates,  situated  in  their  usual  positions.  The  exoccipital 
sometimes  fuses  with  the  supraoccipital,  which  is  produced  beyond  a  line 
drawn  between  the  posterior  extremities  of  the  squamosal.  The  foramen 
magnum  is  deeper  than  broad,  and  boiinded  by  the  supraoccipital  and  the 
exoccipitals,  and  occasionally  also  by  the  basioccipital. 

The  squamosal  joins  both  the  proötic  and  opisthotic,  and  is  buttressed  by 
the  quadrate,  which  penetrates  the  otic  region  by  means  of  a  superiorly  or 
inwardly  directed  process,  and  is  suturally  united  with  the  quadrato-jugal. 
The  quadrate  sometimes  joins  both  the  basisphenoid  and  basioccipital,  but  in 
all  Cryptodires  it  is  separated  from  the  basisphenoid  by  the  pterygoids,  which 
form  a  suture  with  the  basioccipital,  or  very  nearly  reach  the  latter  bone,  and 
are  in  contact  with  the  maxillae  (except  in  the  Chelonidae).  In  none  of  the 
Pleurodires  do  the  pterygoids  extend  posteriorly  beyond  the  quadrate. 
VOL.  II  •    O 


194 


EEPTILIA 


The  mandibular  elemeiits,  which  are  six  in  number,  are  so  intimately 
united  in  the  adult  as  to  appear  like  a  single  piece.  A  symphysial  suture  is 
present  in  the  Chelydridae,  however,  at  least  in  young  individuals.  Teeth  are 
entirely  wanting,  both  on  the  palate  and  jaw-bones,  but  the  edges  of  the  latter 
are  covered  with  sharp,  horny  sheaths  like  the  beak  of  a  bird. 

Limh-girdles. — The  limb-girdles  (Fig.  299)  are  remarkable  for  being  enclosed 
within  the  external  shell,  but  as  they  precede  the  development  of  the  anterior 

and  posterior  dorsal  ribs 
in  the  embryonic  State, 
their  apparently  abnormal 
Position  is  seen  to  be  a 
secondary  modification.  Of 
the  three  branches  which 
constitute  the  pectoral 
arch,  namely,  the  scapula, 
precoracoid,  and  coracoid, 
the  latter  is  longest  in  the 
Chelonidae,  the  former  in 
all  other  Cryptodires.  The 
coracoids  are  long,  distally 
expanded  bones,  directed 
backwards  and  inwards, 
but  not  meeting  in  the 
median  line.  The  scapula 
is  slender,  rod-like,  and 
upwardly  directed.  Its 
distal  extremity  is  attached 
by  ligaments  or  cartilage 
to  the  anterior  costal  bone, 
and  its  proximal  end  is 
f  used  with  the  precoracoid, 
which  corresponds  to  an 
elongated  acromial  process 
("  proscapula,"  Baur  ; 
"  clavicle,"  Cuvier,  Owen). 
The  latter  is  directed  for- 
wards  and  downwards,  and 
its  expanded  distal  end  is  attached  by  ligaments  to  the  entoplastron.  The 
humerus  exhibits  a  large  spherical  head,  and  a  more  or  less  strongly  curved 
shaft.  The  radius  and  ulna  are  of  about  equal  length,  except  in  the  Chelonidae, 
where  the  former  is  much  longer  and  situated  below  the  ulna.  The  proximal 
carpals  are  commonly  four  in  number,  and  the  distal  five ;  numerous  varia- 
tions,  however,  are  exhibited  by  the  bones  of  the  manus  amongst  the  different 
families  and  genera.  Five  digits  are  always  present,  but  sometimes  not  more 
than  three  are  clawed. 

In  the  pelvic  arch  the  long  ilium  is  loosely  attached  to  the  sacrum  and 
eighth  costal  plate  in  the  Cnjptodira,  to  the  sacral  ribs  in  the  Trionychoidea  ; 
but  in  all  existing  Pleurodira  the  pelvis  is  solidly  united  with  the  carapace  and 
plastron,  and  bears  no  trace  of  sacral  attachment  (Fig.  307).  The  pubis  and 
ischium  of  Cryptodires  form  a  ventral  Symphysis,  and  their  symphysial  branches 


Fig.  299. 

Cistudo  lutaritt,  Marsili.  [C.  {Emys)  europaea,  Schneid.]  Recent ; 
Europe.  Ventral  aspect,  the  plastron  reinoved  to  one  side.  c,  Costal 
plates  ;  co,  Coracoid  ;  e,  Entoplastron  ;  ep,  Epiplastron  ;  /,  Fibula  ;  fc, 
Femur  ;  h,  Humerus  ;  hpp,  Hypoplastron  ;  hyp,  Hyoplastron  ;  jl,  Ilium  ; 
js,  Ischium  ;  m,  Marginals  ;  nii,  Nuchal ;  pb,  Pubis  ;  psc,  Precoracoid  ; 
p.V,  Suprapygal ;  r,  Radius  ;  sc,  Scapula  ;  f,  Tibia  ;  u,  Ulna  ;  xp,  Xiphi- 
plastron. 


ORDER  VI  CHELONIA  195 

are  either  widely  separated  from  eacli  other,  or  in  coiitact  and  limiting  two 
obturator  foramina  {Testudinidae).  The  pubis  sends  off  a  more  or  less  developed 
process,  directed  forwards  and  outwards,  which  may  be  subcylindrical,  rod-like, 
or  flat  and  expanded  distally  ;  a  lateral  process  is  also  present,  but  usually  less 
developed  than  that  of  the  pubis,  on  the  ischium  of  all  Cryptodires  except  in 
the  Chelonidae  (Boulenger).  The  femur  is  a  curved  cylindrical  bone,  and  the 
tibia  and  fibula  are  subequal  in  length.  An  astragalus  (formed  of  the  tibiale  + 
intermedium)  which  is  in  contact  with  both  tibia  and  fibula,  and  a  small  outer 
calcaneum  (fibulare)  constitute  the  proximal  tarsals ;  or  among  the  Emyds, 
these  may  coalesce  in  a  single  piece.  A  centrale  is  distinct  in  the  Clielydridae 
and  most  Pleurodires  ;  and  except  in  the  Chelonidae,  which  have  four,  the 
distal  row  of  tarsals  contains  five  bones. 

Hahitat  and  Geologkai  History. — Many  of  the  Chelonia  are  terrestrial  in  habit, 
a  greater  number  are  aquatic,  and  a  few  are  exclusively  marine.  About  200 
recent  species  are  regarded  as  well  established,  most  of  which  are  limited  to 
the  tropics  or  warm  temperate  zones.  The  earliest  known  fossil  remains  are 
from  the  Upper  Keuper  of  Würtemberg  (Pivganochelys,  Chelytherium),  and  are 
fortunately  tolerably  well  preserved.  None  have  been  discovered  in  Lower 
Jurassic  rocks,  but  from  the  Upper  Jura  of  Solothurn,  Northern  France, 
Germany,  England,  and  the  United  States,  a  number  of  fornis  are  known,  all 
of  whick  are  closely  similar  to  existing  genera.  Numerous  Chelonian  remains 
occur  in  the  Cretaceous  and  Tertiary,  but  complete  skeletons  in  association 
with  the  skull  are  extremely  rare.  The  only  noteworthy  marks  of  evolution 
affecting  the  order  since  early  Cretaceous  time  are  degeneration  of  the  carapace 
and  plastron  in  certain  types,  and  elongation  of  the  phalanges  in  truly  marine 
forms. 

Baur  supposes  ancestral  Chelonians  to  have  had  a  habitat  similar  to  that 
of  modern  Crocodiles,  namely  in  shallow  water  or  in  swamps.  A  branch  then 
arose  which  inhabited  rivers,  and  whose  most  specialised  members  are  the 
three-clawed  mud-turtles  (Trionyehoidea).  That  these  forms  with  soft  marginal 
plates  are  descended  from  a  group  having  completely  ossified  marginals  there 
can  be  little  doubt.  From  a  fluviatile  habitat,  according  to  Baur,  these  early 
Chelonians  passed  on  to  a  marine,  prior  certainly  to  the  Cretaceous  period, 
since  we  find  here  such  specialised  genera  as  Protosfega,  Protosphargis,  Allo- 
/deuron,  etc. ;  and  the  most  specialised  of  all  is  the  recent  DermocMys.  Still 
another  branch  acquired  amphibian  habits,  like  many  of  the  Emydidae,  and  in 
time  some  of  these  {Terrapene,  Nicoria,  etc.)  became  truly  terrestrial.  The  land 
tortoises  (Tesfudinidae),  a  highly  specialised  group,  are  initiated  in  the  Eocene 
(Iladnanus),  and  are  completely  adapted  for  a  terrestrial  existence. 

Sub-Order  A.     TRIONYCHOIDEA.     Bonaparte. 

Dorsal  vertehme  and  ribs  fased  with  the  dermal  plates  to  form  an  incompletely 
ossified  carapace  ornamented  with  coarse  vermicidating  scidpture ;  no  epidermal 
shields.  Neck  bending  by  a  sigmoül  curve  in  a  vertical  plane.  Skull  with  descend- 
ing  parieto-pterygoidal  processes.  Pterygoids  hroad  throughout,  separated  from  each 
other,  the  basisphenoid  joining  the  palathies.  Cervical  vertebrae  without  transrerse 
processes.  Sacral  and  caadal  ribs  generally  attached  to  well-developed  transrerse 
processes  of  the  neural  arches.  Pelvis  free  from  the  carapace  and  plastron.  Limbs 
modified  into  paddles,  the  fourth  digit  with  at  hast  four  phalanges,  and  only  the  fhree 


196 


EEPTILIA 


CLASS  III 


inner  digits  clawed.  Marginal  hones  absent  or  forming  an  incomplete  series,  not 
connected  wüh  the  ribs.  Nim  ylastral  Clements;  epiplastra  separated  from  the 
hyoplastra  by  the  y-shaped  entoplastron. 

The  group  of  three-clawed  inud-turtles,  which  appears  first  in  the  Upper 
Cretaceous  of  the  United  States,  and  next  in  the  lowest  Tertiary  strata  of 
both  Europe  and  North  America,  exhibits  the  most  generalised  structure  of 
all  Chelonians.  The  shell  is  incompletely  ossified,  and  the  plastral  elements 
remain  separate  throughout  life.  Yacuities  persist  in  the  carapace,  and  various 
portions  of  the  skeleton  afFord  evidence  of  imperfect  ossification.  There  are 
no  free  nasals,  and  no  parieto-squamosal  arch ;  the  descending  processes  of 
the  prefrontal  may  or  may  not  be  connected  with  the  vomer,  the  epipterygoids 
are  free,  and  the  dentaries  distinct.  The  stapes  is  entirely  surrounded  by 
the  quadrate.  The  pterygoid  is  broad,  without  lateral  expansions,  separating 
the  quadrate  and  basisphenoid.     Only  one  family  is  recognised. 


Family  1.     Trionychidae.     Gray 


Skull  depressed,  the  small  orbits  directed 


more  or  less  upwards  and  appvximated 
towards  the  nares  ;  temporal  fossae 
completely  open,  and  squamosal  and 
supra-occipital  with  very  long  pos- 
terior processes.  Plastron  totally 
distinct  from  the  carapace,  with 
large  vacuities.  Humerus  much 
cnrved.     Eocene  to  Eecent. 

The  existing  members  of 
this  family,  numbering  in  all 
about  twenty-five  species,  are  of 
fluviatile  habit,  and  distributed 
in  the  tropical  and  temperate 
zones  of  all  the  continents 
except  South  America.  Most 
of  the  fossil  forms  belong  to 
the  genus  Trionyx,  Gray  (Fig. 
300),  which  survived  in  Europe 
throughout  the  Eocene  and 
Fig.  300.  Miocene,  and  still  inhabits  the 

rivers  of  Asia,  Africa,  and 
North    America.      Axestus  and 

Plasiomenus,  Cope,  from  the  Eocene  of  Wyoming  and  New  Mexico,  are  closely 

related  genera.     Chitra,  G-ray,  is  Pliocene  and  Recent. 


Trionyx  styriactis,  Peters.     Miocene  lignites  ;  Ebiswald,  Styria. 
Imperfect  carapace  and  cast  of  ribs.     1/4  (after  Peters). 


Sub-Order  B.     CRYPTODIRA.     Dumeril. 

Dorsal  vertebrae  and  ribs  fused  and  expanded  into  bony  plates  forming  a  carapace. 
Neck  bending  by  a  sigmoid  ciirve  in  a  vertical  plane.  Gervical  vertebrae  without  or  with 
mere  indications  of  transverse  processes.  Posterior  cervicals  with  two  articular  faces. 
Skull  with  descending  parieto-pterygoidal  processes  {except  in  the  Dermochelyidae). 
No  free  nasals  ;  parieto-squamosal  arch  present  01^  absent ;  descending  process  of  the 
prefronfals  connected  with  the  vomer  ;  stapes  in  an  open  groove,  entirely  covered  by  the 


ORDER  VI  CHELONIA  I97 

quadrate  behind.  Pterygoids  narrow  in  the  middle,  in  contad  only  along  the  median 
line,  without  wing-like  lateral  expansions,  separating  the  quadrate  and  basisphenoid. 
Pelvis  not  anchylosed  with  carapaee  or  plastron.  Digits  with  not  mme  than  three 
phalanges.  Epiplastra  in  contad  with  hyoplastra  ;  entoplastron  oval,  rhomboidal,  or 
T-shaped.     A  complete  series  of  marginal  bones,  conneded  with  the  ribs. 

This  sub-order  comprises  the  majority  of  existing  and  fossil  Chelonians. 
As  distinguished  from  Pleurodires,  the  head  is  retracted  by  curvature  of  the 
neck  in  a  vertical  plane,  and  the  pelvis  is  unconnected  with  the  plastron. 
The  different  families  are  conveniently  grouped  by  Baur  in  four  superfamilies, 
as  recognised  in  the  sequel. 

Superfamily  1.     CHELONOIDEA.     Baur. 

A  parieto-squamosal  arch  ;  no  foramen  palatinum  between  palatines  and  maxillae; 
articular  faces  between  the  sixth  and  seventh  cervical  vertebrae  plane ;  nuchal  with  a 
distind  process  on  the  lower  side  for  articulation  with  the  neural  arch  of  the  eighth 
cervical  verfebra,  o.nd  without  lateral  processes,     One,  biconvex  cervical  vertebra. 

Family  1.     Dermochelyidae.     Gray.     {Athecae,  Cope.) 

Carapaee  broken  up  into  numerous  mosaic-like  pieces  of  dermal  ossification,  wholly 
unconnected  with  the  vertebrae  and  ribs.  Epidermal  shields  absent.  Skull  without 
descending  parietal  processes;  temporal  region  completely  roofed,  the  squamosal 
joining  the  parietal.  Humerus  flattened  ;  limbs  paddle-shaped,  clawless, .  the  digits 
of  the  manus  much  elongated  ;  phalanges  without  condyles.     Tertiary  and  Recent. 

Eosphargis,  Lyd.  Carapaee  represented  by  a  single  median  row  of  broad 
carinated  seutes  and  a  series  of  marginals  on  either  side.  Plastron  probably 
devoid  of  tesserae.     Skull  broad  and  flat.     Eocene  ;  England. 

Psephophorus,  v.  Meyer  {Macrochelys,  van  Beneden  non  Gray).  Skull 
shorter,  thicker,  and  relatively  larger  than  in  Dermochelys ;  shell  completely 
tessellated,  sculptured ;  seutes  of  the  larger  longitudinal  row  of  the  carapaee 
devoid  of  carinae.     Eocene  and  Oligocene ;  Europe. 

Dermochelys,  Blv.  (Sphargis,  Merrem).  Carapaee  completely,  plastron  in- 
completely  bony  in  the  adult,  the  former  with  seven,  the  latter  with  five 
keels  ;  plastral  elements  eight.  Recent ;  Atlantic,  Pacific,  and  Indian  Oceans. 
In  this,  the  largest  and  sole  surviving  member  of  the  family,  the  Separation 
of  the  vertebral  column  from  the  carapaee  was  deemed  by  Cope,  Dollo,  and 
others  a  character  of  sufficient  importance  to  Warrant  the  establishment  of  a 
group  (Athecae)  equal  in  value  to  the  rest  of  the  Chelonia.  Baur  has 
endeavoured  to  prove  that  the  mosaic-like  carapaee  was  an  acquired  character, 
and  that  this  and  the  following  family  are  directly  related  to  the  Chelonidae. 

Family  2.     Protostegidae.     Cope. 

Carapaee  represented  merely  by  a  row  of  marginals,  but  the  plastron  very  strongly 
developed  and  composed  of  thick  ossifications.  Skull  with  descending  parietal  plates. 
Humerus  with  the  radial  process  short,  Munt,  and  approximated  to  the  head.  Creta- 
ceous  and  Tertiary. 

Profostega,  Cope.  Descending  parietal  plates  well  developed.  Carapaee 
intermediate  between  Dermochelyidae  and  Chelonidae,  with  several  primitive 


198  EEPTILIA  class  m 

characters  regarded  as  ancestral  to  both.  Plastron  with  larger  bones  and  a 
much  smaller  fontanelle  than  in  Dermochelys.  Body  elongate,  the  posterior 
end  truncated ;  limbs  paddle-shaped.  Post-axial  border  of  humerus  more  or 
less  deeply  emarginate.     Upper  Cretaceous  ;  North  America. 

Archeion,  Wieland.  Larger  than  the  preceding,  but  similar  in  most 
respects.     Ft.  Pierre  Cretaceous  ;  South  Dakota. 

Protosphargis,^  Cap.  Skull  unknown.  Body  skeleton  similar  to  that  of 
Protostega,  but  bones  of  plastron  more  slender,  and  median  fontanelle  larger. 
Uppermost  Cretaceous ;  Italy. 

Pseudosphargis,  Dames.  Skull  flat  and  wide,  like  that  of  the  Dermo- 
chelyidae,  but  with  descending  parietal  processes.     Oligocene  ;  Germany. 

Family  3.     Ohelonidae.      Gray.     (Marine  Turtles.) 

Shell  more  or  less  incompletely  ossified,  covered  loith  epidermal  shields.  Carapace 
frequenfly  cordiform. ;  plastral  bones  nine,  distinä  from  the  carapace,  and  with  vacuities 
and  digitale  lateral  extremities  ;  nuchal  without  costiform  process.  Temporal  region 
of  skull  completely  roofed  over  ;  squamosal  joining  the  parietal,  and  the  latter  articn- 
lating  with  the  postfrontal.  Limbs  paddle-shaped,  phalanges  without  condyles,  terminal 
claws  reduced  to  one  or  two.  Supramarginal  shields  present,  and  sometimes  an  inter- 
gular.     Upper  Cretaceous  to  Recent. 

Osteopygis,  Cope  (Catapleura,  Cope).  Carapace  practically  closed;  marginals 
eleven.     Upper  Cretaceous. 

Allopleuron,  Baur.  Carapace  long  and  narrow,  nuchal  deeply  emarginate, 
neurals  short  and  wide  with  a  long  keel ;  marginals  long  and  slender.  Upper 
Cretaceous. 

Lytoloma,  Cope  {Euclastes,  Puppigerus,  p.p.,  Cope ;  Glossochelys,  Seeley ; 
Erquelinnesia,  Pachyrhynchus,  Dollo).  Skull  resembling  that  of  Thalassochelys. 
Carapace  rounded  posteriorly,  vacuities  of  shell  more  obliterated  than  in 
Thalassochelys ;  epiplastrals  narrow ;  exposed  portion  of  entoplastron  very 
short ,  xiphiplastrals  uniting  extensively  in  the  median  line.  Upper  Creta- 
ceous and  Eocene. 

Argillochelys,  Lyd.  Skull  short  and  wide.  Shell  and  bones  of  the  pectoral 
arch  similar  to  those  of  Thalassochelys,  except  that  the  carapace  has  but  four 
costal  shields,  and  the  xiphiplastrals  unite  extensively  along  the  median  line. 
Eocene ;  England. 

Thalassochelys,  Fitz.  (Fig.  301).  Carapace  completely  ossified  in  the  adult, 
with  at  least  five  pairs  of  costal  shields,  and  vacuities  more  or  less  obliterated. 
A  series  of  inframarginal  plastral  shields  present.     Eocene  to  Eecent. 

Chelone,  Brong.  (Mydas,  Gray  ;  Cimochelys,  Owen),  (Figs.  297,  302).  Skull 
comparatively  long,  narrow,  with  the  orbits  lateral.  Shell  cordiform  or 
pointed  at  both  ends,  with  four  costal  shields,  the  plastral  vacuities  persisting 
for  a  long  period.  An  intergular  and  a  series  of  inframarginal  shields  present. 
Upper  Cretaceous  to  Recent. 

Lembonax,  Cope.  Eocene ;  North  America.  Chelyopsis,  van  Beneden. 
Oligocene  ;  Belgium  and  Northern  Germany. 

During  the  Cretaceous  and  Tertiary  numerous  marine  turtles  existed  which 
are  perhaps  most  nearly  related  to  the  Ohelonidae,  but  owing  to  their  diversity 
have  been  placed  by  some  authors  in  independent  families.     Most  of  them. 


ORDER  VI 


CHELONIA 


199 


however,  are  too  imperfectly  known  to  admit  of  a  precise  account  of  their 
structure  or  taxonomy. 

Propleura  and  Peritresius,  Cope,  from  the  Upper  Cretaceous  of  the  United 
States,  are  represented  by  a  few  species,  all  under  1  m.  in  length.     Desmato- 


FiG.  301. 

Thalassochelys  carctta,  Liun.  sp.  Recent ;  Mediterraiiean.  Ventral  aspect 
of  skeleton,  the  plastron  renioved.  cor,  Coracoid  ;  h,  Hmnerus ;  psc,  Pre- 
coracoid  ("prescapula,"  Baur);  r,  Radius;  sc,  Scapula ;  u,  Ulna. 


Fig.  302. 

Chelone  hofmanni,  Gray. 
Upper  Cretaceous ;  Maestricht, 
Holland.    Portion  ofcarapace,  i/g. 


cheli/s,  Williston,  from  the  Fort  Benton  Cretaceous  of  Kansas  and  Nebraska,  is 
a  peculiar  form  with  some  aberrant  characters,  such  as  free  nasals,  stout 
transverse  processes  on  the  cervical  vertebrae,  and  a  single  articular  face'on 
the  posterior  cervicals.     Puppigerus,  Cope,  occurs  in  the  Miocene  of  New  Jersey. 

Superfamily  2.     CHELYDEOIDEA.     Baur. 

No  pariefo-squamusal  arch  ;  a  foramen  palatmum  hetween  palatine  and  maxilla  ; 
articular  faces  hetween  the  sixth  and  sevenfh  cervical  veiiehrae  not  plane;  niichal 
without  lower  process,  hut  with  more  or  less  strong  lateral  process  underlying  the 
peripherals  ;  one  hiconvex  cervical ;  a  complete  series  of  inframarginals. 


Family  1.     Thalasseraydidae.     Rütimeyer.     (Acichelyidae,  Lydekker.) 

Temporal  fossae  of  skull  partially  roofed.     Shell  cm'difm'm,  mare  (yr  less  in- 
completely  ossified,  the  fontaneUe  in  plastron  persisting  for  a  long  period  w  thronghout 


200 


REPTILIA 


CLASS  III 


life.  Nuchal  without  costifonn  process.  Plastron  connected  with  carapace  hy  axillar  1/ 
and  inguinal  buttresses.  Humerus  with  imperfectly  developed  liead  and  nearly  straight 
shaft.  Phalanges  with  articular  condyles,  all  the  terminal  ones  clawed.  Upper  Jura 
and  Cretaceous. 

This  family  includes  a  number  of  Mesozoic  genera  which  combine  the 
characters    of    both   marine    and   marsh    turtles,    and    are    probably   directly 

ancestral  to  the  Chelonidae.  They 
appear  to  have  been  mainly  of  marine 
habits.  The  very  incomplete  ossification 
of  the  carapace  and  persistent  fontanelle 
of  the  plastron  present  the  same  conditions 
as  in  sea-turtles,  while  the  form  of  the 
plastral  elements  and  the  outwardly  bent 
extremities  of  the  hyo-  and  hypo-plastrals 
are  suggestive  of  marsh  forms.  The  five 
functional  toes  with  articulating  phalanges 
were  all  clawed  and  probably  webbed  in 
life,  having  been  adapted  for  both  pro- 
gression  on  land  and  for  swimming. 

Thalassemys,  Eüt.  (Enaliochelys,  Seeley). 
Carapace  moderately  thick,  flattened,  with 
well-ossified  pleurals,  the  posterior  neurals 
not  forming  a  tectiform  ridge.  Vertebral 
shields  narrow.  Very  large  persistent 
vacuities  in  the  plastron.  Upper  Jura ; 
Switzerland  and  England. 

Eurysternum,  Wagler  (Achelonia, 
Acichelys,  Aplax,  Palaeomedusa,  v.  Meyer; 
Euryaspis,  Wagner),  (Fig.  303).  Carapace 
fiattened,  distinctly  emarginate  anteriorly, 
with  the  pleurals  well  ossified  and  pos- 
terior neurals  not  forming  a  tectiform 
ridge.  Vertebral  shields  very  wide,  mar- 
ginale long  and  narrow.  Plastron  with  large  persistent  vacuities.  Upper 
Jura  (Lithographie  Stone) ;  Bavaria  and  Cerin,  Ain. 

Tropidemys,  Rütimeyer  ;  Pelobatochelys,  Seeley.  Upper  Jura  and  Wealden  ; 
Europe. 

Chitracephalus,  Dollo.  Cranium  much  elongated  and  depressed,  with  an 
extremely  short  facial  region,  and  temporal  fossae  not  roofed.  Cervical 
vertebrae  without  transverse  processes.  Pleurals  narrowed  at  their  outer 
ends,  with  vacuities  within  the  well-developed  border  of  the  peripherals. 
Plastral  elements  similar  to  those  of  Chelone.  Digits  clawed,  not  greatly 
elongated.     Wealden  ;  Belgium.     C.  dumoni,  Dollo. 


Fig.  303. 

Eiirysternuvi  wagleri,  v.  Meyer.     Upper  Jura 
Zandt,  near  Eichstädt,  Bavaria.     1/3. 


Family  2.     Ohelydridae.     Agassiz. 

Temporal  region  of  skull  incompletely  roofed  over ;  no  parieto-squamosal  arch. 
Frontals  excluded  from  orbit ;  maxilla  separated  from  the  quadratojngal ;  squamosal 
in  connection  with  postorbitofrontal.  Epidermal  shields  absent  in  some  cases  ;  number 
of  neurals  complete  ;  posterior  pleurals  meeting  in  the  median  line.     Shell  usually  not 


ORDER  VI  CHELONIA  201 

fulhj  ossißed  until  late  in  life.  Plastron  frequently  small,  cruciform,  articulating  with 
the  carapace  hy  gomphosis  ;  an  entoplastron  present.  Nuchal  cmargimife,  with  a  long 
costiform  process  underlying  the  anterior  marginals.  Numher  of  marginals  eleven ; 
a  series  of  inframargirials.  Limhs  not  modified  into  paddles ;  digits  moderat ely 
elongate,  webhed  ;  claws  four  or  five.     Upper  Jura  to  Recent. 

Tretosternum,  Owen  {Pelfochelys,  Dollo).  Carapace  with  pustulate  sculpture, 
the  anterior  border  deeply  emarginate ;  plastron  with  an  intergular  and  five 
pairs  of  plastral  shields.  Epidermal  shields  present.  Purbeck  and  Wealden ; 
England  and  Belgium. 

Platychelys,  Wagner,  from  the  Upper  Jura,  is  sometimes  referred  to  this 
family. 

Toxochelys,  Cope.  Skull  with  tympanic  ring  open.  Caudal  vertebrae 
procoelous,  with  well-developed  chevron  bones.  Upper  Cretaceous ;  United 
States. 

PortJwchelys,  Will.  Skull  broad,  alveolar  margin  very  deep.  Carapace 
completely  ossified,  smooth,  the  arrangement  of  bones  and  shields  nearly  as 
in  Chelydra.  Plastron  with  very  small  fontanelies  and  no  sternal  bridge. 
Upper  Cretaceous  ;  United  States. 

Anostira,  Leidy.  Shell  with  vermiculated  sculpture  and  without  (or  with 
very  thin)  epidermal  shields.  Plastron  articulated  with  the  carapace  by 
suture,  and  bridge  without  distinct  inguinal  notch.  Skull  unknown.  Upper 
Eocene ;  United  States. 

Pseudotrionyx,  Dollo.  Eocene  ;  Belgium  and  England.  Acherontemys,  Hay. 
Miocene ;  Washington. 

Chelydra,  Schweig.  Shell  with  the  emargination  of  the  nuchal  not  very 
deep;  neural  bones  mostly  hexagonal;  supramarginal  shields  absent ;  posterior 
border  of  carapace  serrated.  Miocene  to  Recent.  C.  murchisoni,  Bell.  Upper 
Miocene ;  Switzerland. 

Macrodemmys,  Gray  (Macrochelys,  Gray ;  Gypochelys,  Agassiz).     Recent. 

Family  3.     Dermatemydidae.     Gray. 

Skull  with  open  temporal  fossae  ;  frontals  not  excluded  from  orbit ;  maxilla  un- 
conneded  with  quadratojugal,  and  squamosal  separated  from  postorhito-frontal.  Shell 
covered  with  epidermal  shields  ;  plastral  bones  nine ;  plastral  shields  separated  from 
the  marginals  by  a  series  of  inframarginals.  Plastron  united  with  the  carapace  by 
suture  or  ligaments.  Nuchal  bone  produced  into  costiform  processes,  underlying  the 
marginals.  Number  of  neurals  incomplete ;  posterior  pleurals  not  meeting  in  the 
median  line.  Pubic  and  ischiadic  symphyses  widely  separated.  Digits  moderately 
elongate,  claws  four  or  five.     Cretaceous  to  Recent. 

This  family  comprises  three  existing  genera  restricted  to  Central  America, 
and  a  number  of  fossil  forms,  such  as  Adocus,  Agomphus  {Amphiemys),  and  Poly- 
thorax,  Cope  ;  Baptemijs,  Leidy ;  and  Trachyaspis,  von  Meyer.  The  family  is 
intermediate  in  position  between  the  Chelydridae  and  recent  Cinosternidae, 
and  in  some  respects  suggestive  of  Pleurodires.  Adocus,  from  the  American 
Cretaceous,  was  made  by  Cope  the  type  of  an  independent  family,  character- 
ised  by  the  abortion  of  the  heads  of  the  ribs. 

The  Cinosternidae,  including  Cinosternum  {Kinosternon),  Aromochelys,  and 
Goniochelys;  and  the  Staurotypidae,  including  Staurotypus  and  Claudius,  are 


202 


REPTILIA 


CLASS  III 


without  representatives  in  the  fossil  state.  The  same  is  true  of  the  third 
superfamily  r.ecognised  by  Baur,  the  Platysternoidea,  comprising  the  family 
Platysternidae  with  the  solitary  genus  Flatysternum,  Gray. 

Superfamily  4.     TESTUDINOIDEA.     Baur. 

Skull  without  parieto-squamosal  arch,  and  squamosal  separaied  from  iiostorhito- 
frontal,  with  a  foramen  palatinum  hetween  the  palatine  and  maxilla.  Articulm 
faces  hetween  the  sixth  and  seventh  cervical  vertebrae  not  plane,  and  two  of  the  cervicals 
biconvex.  Nuchal  without  well-developed  costiform  processes  ;  series  of  inframo/rginals 
incom 


Family  1.     Emydidae.     Gray.     (Marsh  Turtles.) 

Shell  completely  ossified  in  the  adult,  covered  with  epidermal  shields.  Carapace 
onhj  moderately  convex.  Plastron  sometimes  hinged,  with  long  sternal  bridge  and 
large  sternal  Chambers,  the  marginals  of  bridge  without  median  processes  interlocking 
with  the  rib-ends.  Plastral  bones  nine,  mesoplastron  and  intergulars  wanting.  Lateral 
temporal  arch  usually  present,  quadrate  open  behind.  Digits  short  and  st  out,  the 
second  and  third  ivith  more  than  two  phalanges  ;  claws  four  or  five.  Tertiary  and 
Recent. 

The  Emyds  or  Marsh  Turtles  are  very  closely  related  to  the  Land  Tortoises, 
and  are  sometimes  included  with  them  in  the  same  family.     The  shell,  how- 


Stylemys  nebrascensis,  Jjeidy. 


Fig.  304. 

White  River  Oligocene  ;  South  Dakota. 
1/3  (after  Leidy). 


riastrou  and  carapace, 


ever,  in  the  Emyds  is  less  convex,  the  sternal  Chambers  are  larger,  and  their 
limbs  are  without  dermal  ossifications.  Their  distribution  at  the  present  day 
is  World -wide  with  the  exception  of  the  Australian  region.  Fossil  marsh 
turtles  make  their  first  appearance  in  the  Eocene,  and  belong  for  the  most 
part  to  existing  genera. 

Emys,  Dumeril  (Lutremys,  Gray).  Neural  bones  short,  hexagonal  ;  nuchal 
not  distinctly  emarginate.  Plastron  united  to  the  carapace  by  ligament,  and 
more  or  less  hinged  in  the  adult.     Eocene  to  Recent. 


ORDER  VI  CHELONIA  203 

Ptijcliogaster,  Pomel.  Neural  bones  short ;  pleurals  alternately  long  and 
short  at  their  inner  and  outer  extremities  ;  nuchal  emarginate.  Hyoplastrals 
united  to  the  carapace  by  suture,  the  hypoplastrals  joining  it  by  a  straight 
ligamentous  union,  and  movable  upon  a  transverse  hinge.  Oligocene  or  Lower 
Miocene ;  France. 

Stylemys,  Leidy.  Skull  unknown.  Shell  with  the  general  characters  of 
Testudo,  but  with  all  or  nearly  all  of  the  neural  bones  hexagonal,  with  short 
antero- lateral  surfaces ;  the  nuchal  not  emarginate;  posterior  caudals  not 
alternating  in  length ;  caudal  shield  undivided.  Oligocene  to  Pliocene ; 
Western  United  States.  S.  nehmsccnsis,  Leidy,  the  type  species,  is  very 
abundant. 

CisfiidOj  Fleming  (Fig.  299)  ;  Cycle7nys,  Bell.  Recent.  Damonia,  Bellia, 
Nicoria,  Gray.  Pliocene  and  Recent,  Ocadia,  Gray ;  Clemmys,  Wagler. 
Miocene  to  Recent. 

Family  2.     Testudinidae.     Gray.     (Chersidae.)     Land  Tortoises. 

Skidl  with  open  temporal  fossae ;  quadrate  dosed  hehiiul.  Shell  compleiely 
ossified  even  in  the  young,  more  or  less  ovoid,  and  covered  with  epidermal  shields. 
Plastron  suturally  united  with  the  marginals ;  an  entoplastron  present.  Sternal 
hridge  long,  sternal  Chambers  very  slightly  developed  ;  anterior  and  posterior  extremities 
of  hyo-  and  hypo-plastron  little  extended  inwards ;  marginals  of  hridge  with  median 
processes  interlocking  with  rib  ends.  Shdl  with  open  temporal  fossae  ;  quadrate  closed 
behind.  Pubic  and  ischiadic  symphyses  firmly  connected  with  each  other.  Limbs  with 
free  digits,  which  are  short  and  moderat ely  elongate ;  terminal  claws  four  or  five. 
Second  and  third  digit  of  pes  never  with  more  than  two  phalanges.  Tertiary  and 
Recent. 

Cinixys,  Bell  {Kinixys,  Bell ;  Cinothorax,  Fitz.).  Posterior  portion  of  cara- 
pace movable  in  the  adult,  hinged  between  the  seventh  and  eighth  marginals 
and  the  fourth  and  fifth  pleurals.     Gulars  distinct.     Recent ;  Africa. 

Pyxis,  Bell.  Carapace  without  hinge ;  front  lobe  of  plastron  mobile. 
Recent. 

Homopus,  Dum.  and  Bibr.  Carapace  and  plastron  without  hinge.  Palate 
without  oral  ridge.     Eocene  to  Recent. 

Hadrianus,  Cope.  Distinguished  from  Testudo  by  the  narrow  vertebral 
shields,  usually  hexagonal  neural  bones,  undivided  caudal  shield,  and  more 
uniform  length  of  extremities  of  the  pleural  bones.     Eocene  ;  North  America. 

Testudo,  Linn.  {Colossochelys,  Falc.  and  Caut. ;  Manouria,  Gray  ;  Xerobates, 
Ag.).  Neural  bones  short ;  pleurals  alternately  short  and  long  at  their  inner 
and  outer  extremities  ;  nuchal  deeply  emarginate.  Plastron  extensively  united 
with  the  carapace  by  suture ;  buttresses  short,  never  extending  beyond  the 
edge  of  the  costals.  Vertebral  shields  broad,  costals  very  short.  Miocene  to 
Recent.  Some  Pliocene  species  attain  gigantic  size,  the  shell  of  T  perpiniana, 
Deperet,  from  the  Pliocene  of  France,  having  a  length  of  1-2  m.,  and  that  of 
T.  atlas,  Falconer  and  Cautley,  from  the  Pliocene  of  the  Siwalik  Hills,  India, 
upwards  of  2  m. 

Sub-Order  C.     PLEURODIRA.     Dumöril. 

Skull  with  outer  border  of  tympanic  cavity  completely  encircled  by  the  quadrate  ; 
Ijterygoids  very  broad  throughout,  forming  wing-like   lateral   expansions,  and  not 


204  REPTILIA  class  iii 

separating  the  qitadrate  and  hasisphenoid ;  nasals  free  or  united  with  prefronfals  ;  the 
latter  without  desceiiding  processes.  Neck  bending  laterally;  cervical  vertebrae  with 
strong  transverse  processes  and  Single  articular  faces.  Shell  usually  covered  with 
epidermal  shields ;  a  complete  series  of  marginal  hones  connected  with  the  ribs  ; 
epiplastra  in  contact  with  hyoplastra;  mesoplastrals  present  in  some  forms,  and  an 
intergular  in  all  cases  where  epidermal  shields  occur.  Pelvis  anchylosed  to  carapace 
and  plastron.     Digits  with  not  more  than  three  phalanges. 

In  this  group,  as  indicated  by  the  name,  the  neck  bends  laterally,  and  the 
pelvis  is  anchylosed  to  the  carapace  and  plastron.  A  number  of  fossil  forms 
are  known  which  exhibit  characters  intermediate  between  Pleurodires  and 
Cryptodires,  and  are  here  considered  (following  Baur  and  Lydekker)  as  an 
independent  sub-order,  the  Amphichelydia.  Existing  Pleurodires  are  re- 
stricted  to  the  southern  hemisphere,  and  distributed  in  South  America, 
Southern  India,  Africa,  and  Australia. 

Family  1.     Proganochelyidae. 

Containing  only  the  primitive  Proganochelys,  with  the  characters  of  that 
gen  US. 

Froganochelys,  Baur  (Psammochelys,  Quenst. ;  ?  Chelytherium,  von  Meyer). 
The  following  description  of  this,  the  most  ancient  of  all  Chelonians,  is 
Condensed  from  Fraas ;  known  only  by  the  carapace  and  plastron,  in  one 
specimen  about  0'65  m.  long  and  nearly  as  wide.  Carapace  moderately  convex, 
with  five  vertebral  shields  greatly  enlarged  and  the  costals  correspondingly 
reduced  ;  a  series  of  supramarginal  epidermal  scutes  at  the  antero-  and  postero- 
lateral  angles,  elevated  into  prominences ;  posterior  marginals  large  and  freely 
projecting.  Neural  bones  small,  costals  large  and  extending  with  the  rib  ends 
as  far  as  the  plastron.  Sternal  bridge  long,  mesoplastrals  very  large,  laterally 
expanded,  and  meeting  in  the  middle  line ;  epi-  and  ento-plastron  very  small. 
Pelvis  supported  by  two  sacral  vertebrae ;  ribs  and  pelvis  connected  with  the 
carapace  and  plastron.  Upper  Trias  (Stuben  Sandstone) ;  Würtemberg ; 
P.  quenstedtii,  Baur  ( =  Psammochelys  keuperiana,  Quenst.). 

Family  2.     Miolaniidae.     Owen. 

Shell  known  only  by  fragments.  Skull  with  completely  roofed  temporal  fossae,  and 
furnished  with  horn-like  bony  protuberances ;  no  distinct  nasals;  vomer  dividing 
palatines.  Caudal  vertebrae  opisthocoelous,  with  chevrons  ;  tail  long  and  encased  in  a 
nodose  hony  sheath.     Pleistocene. 

Miolania,  Owen  (Ceratochelys,  Huxley).  Cranium  with  three  pairs  of 
peripheral  prominences  in  the  fronto-parietal  region,  the  head  measuring  in 
one  species  0*6  m.  in  width  to  the  tip  of  the  "horns."  Habits  probably 
herbivorous  and  terrestrial.  Kelated  to  the  Testudinidae,  according  to  Baur. 
Pleistocene;  Queensland  and  Lord  Howe's  Island.  M.  plafyceps,  Owen;  31. 
oweni,  Sm.  Woodw. 

Family  3.     Ohelyidae.     Gray. 

A  strong  parieto-squamosal  arch  ;  posterior  narial  openings  bounded  by  maxillae, 
palatines,  and  vomer ;  frontal  unpaired ;  nasals  free  ;  premaxillae  distinct.     Shell 


ORDER  VI 


CHELONIA 


205 


Cover ed  with  epidermal  shields ;  plastral   hones  nine ;   no   inframarginal   shields. 
Tertiary  and  Recent. 

The  recent  genus  Ghelys,  Dum^ril,  is  made  by  Baur  the  exclusive  repre- 
sentative  of  this  family,  and  separate  families  are  established  for  each  of  the 
following  : — Hydromedusa,  Wagler  (Recent) ;  Chelodina,  Fitz.  (Pleistocene  and 
Recent) ;  and  Bhinemys,  Wagler  (Eocene  to  Recent).  In  Chelodina  neural 
bones  are  absent,  and  the  external  surface  is  more  or  less  vermiculated. 


Family  4.     Rhineraydidae.     Baur. 

A  slender  or  hroad  parieto-squamosal  arch  present ;  posterior  narial  openings 
bowided  by  maxillae,  palatines,  andvomer  ;  frontal  paired ;  nasals  free  ;  premaxillae 
distincf.     Tertiary  and  Recent. 

Ilhinemys,  Wagler  (Phrynops,  Wagler;  Hydraspis,  Bell).  Eocene;  India ; 
and  Recent ;  South  America.  Emydura,  Bonap.  Pleistocene  and  Recent. 
Flatemys,  Wagler;  Elseya,  Gray.     Recent. 

Family  5.     Pelomedusidae.     Cope. 

Qaadratojugal  not  in  conneäion  with  parietal ;  vomer  rudimentary  or  absent.  No 
parieto-squamosal  arch .  and  no  free  nasals  ;  frefrontals  in  contact.  Second  cervical 
biconvex.     Plastral  bones  eleven  ;  mesoplastra  present.     Tertiary  and  Recent. 

This   family,  as   limited  by  Baur,  includes   only   the  recent  Pelomedusa, 
Wagler,  and  Sternothaerus,  Bell.     Cope  regards  the  latter  as   the  type  of  an 
independent  family,  on  account  of  the  complete 
mesoplastrals.     The  Podocnemididae   difFer  from 
the  preceding  genera  in  having  the  quadratojugal 
connected  with  the  parietals.     Under  this  head  are 
included    the    follow- 
ing :  —  Podocnemis, 
Wagler     (Fig.     305). 
Eocene    to    Recent. 
Peltocephalus,  Dum. 
and    Bibr.  ;     Erymno- 
chelys,  Baur.     Recent. 
Daccochelys,  Lyd.     Eo- 
cene ;      and     perhaps 
Taphrosphys,    Cope, 

from    the    Upper    Cre-  Podocnemis    expansa,   Wagler. 

tappnn«  of  T^pw   Tpr^Pv  Recent;   Brazil.     Visceral  aspect  of 

taceOUS  OI  in  ew  J  ersey  posterior  eud    of   plastron,   showing 

and  New  Zealand.  places  for  attachment  of  pubes  and 

„,                            „-  .  ischia,  a-,  2/ (after  Rütimeyer). 

ihe   genus   Ehmo- 

chelys,   Seeley   (Fig.    306),   from  the   Cambridge  Greensand,   known  by   well- 
preserved  skulls  and  various  fragments,  is  of  uncertain  family  position. 

Family  6.     Plesiochelyidae. 

Skull  with  temporal  fossae  roofed.  Shell  usually  thick,  without  mesoplastrals,  and 
with  either  a  reduced  or  the  füll  number  of  neurals  and  suprapygals  ;  only  tJie  pubis 
uniting  with  the  xiphiplastral ;  entoplastral  small ;  inframarginal  shields  at  least 
usually  present.     Sometimes  a  plastral  vacuity.     Phalangeals  reduced.     Upper  Jura. 


Fig.  305. 


Rhinochelys  cantubrhjieiisix,  Lyd. 
Cambridge  Greensand.  Skull,  i/i. 
A,  Orbit;  //•,  Frontal;  N,  Nostril  ; 
na,  Nasal ;  pa,  Parietal ;  jmix,  Pre- 
maxilla  ;  prf,  Prefrontal ;  j)//,  Post- 
frontal (after  Lydekker). 


206 


REPTILIA 


C'LASS  III 


Idioehehjs,  v.  Meyer  {CheJonemys,  Jourdan).  Shell  with  deeply  emarginate 
nuchal ;  neurals  frequently  short  and  interrupted,  never  exceeding  seven  in 
number,  and  not  connected  with  the  one  suprapygal.  Vertebral  shields  very 
broad.     Lithographie  Stone ;  Bavaria  and  Cerin,  Ain.     /.  fitzingeri,  v.  Meyer. 

Flesiochelf/s,  Rut.  {Stylemys,  Maack,  non  Leidy),  (Fig.  307).  Shell  attaining 
a  length  of  0*5  m.,  circular  or  cordiform,  relatively  thick,  considerably  vaulted 


Flesiochclys  solodiirensis,  Rütimeyer.     Upper  Jura  (Kiimueriügiaii) ;  Solothurn,  Hwitzerlaml. 
Vs  (after  Rütimeyer). 

in  the  adult,  and  with  or  without  a  persistent  plastral  vacuity.  Nuchal  niore 
or  less  emarginate ;  neurals  generally  long  and  narrow,  eight  in  number,  and 
connected  with  the  first  of  the  three  suprapygals.  Plastral  bridge  long ; 
sulcus  between  abdominal  and  femoral  shields  ascending  towards  the  hypo- 
plastral  suture,  and  terminating  in  the  middle  of  the  inguinal  notch.  Upper 
Jura  ;  Germany,  Switzerland,  and  France. 

Hf/dropelta,  Parachehjs,  v.  Meyer.     Upper  Jura  ;  Europe.     Ht/laeocheh/s,  Lyd. 
Upper  Jura  and  Wealden  ;  Europe. 


Sub-Order  D.     AMPHICHELYDIA.     Lydekker. 

Nasals  free;  a  squamoso- parietal  arch ;  descerding  processes  of  prefruiäals 
joining  vomer ;  stapes  in  an  open  groove  of  the  quadrate  ;  pterygoids  narrow  in  the 
middle j  without  wing-like  lateral  expansions,  separating  quadrate  aiul  basisphenoid  ; 
epipterygoid  well  developed  and  free;  dentary  hones  distind.  Cervical  vertehrae 
with  well -developed  transverse  processes,  with  single  articular  faces,  biconcave ; 
dorsal  and  sacral  vertehrae  with  well -developed  ribs.  Pelvis  not  anchylosed  to 
the  carapace  and  plastron.  Epiplastra  in  contact  with  hyoplastra,  enfoplastron 
oval  or  rhomboidal ;  a  complete  series  of  marginals  connected  with  the  ribs. 

The  foregoing  definition  of  this  sub-order,  as  given  by  Baur,  is  based 
largely  upon  the  genus  Compsemys,  Leidy,  oldest  North  American  tortoise,  of 
which  nearly  all  parts  of  the  skeleton  are  known.  The  group  was  established 
by  Lydekker  to  include  a  number  of  generalised  later  Mesozoic  forms  having 
a  shell  constructed  on  the  plan  of  that  in  Cryptodires  and  Pleurodires,  in 
which  mesoplastral  bones  and  an  intergular  shield  are  developed.     The  pubis 


ORDER  VI 


CHELONIA 


may  articulate,  without  sutural  union,  with  the  xiphiplastral. 
and  humerus  are  of  a  Pleurodiran  type. 


207 
The  coracoid 


Family  1.     Pleurosternidae.     Lydekker. 

A  provisional  assemblage  embracing  a  variety  of  generalised  fossil  foims^ 
and  to  be  regarded  as  ancestral  to  both  Cryptodires  and  Pleurodires. 

Pleurosternam,  Owen  {Megastermim,  Gray).  Carapace  much  depressed, 
rounded  posteriorly,  without  vacuities,  and  firmly  united  by  a  long  bridge  on 
each  side  with  the  plastron,  which  is  also  continuous.     Surface  of  shell  very 

B  A 

IG? 


CS 


SmS 


BS 


NSi 


Ep 


f. 

C2 

NSn 

Hvij 

Mp 

C3_ 

■  Hpp 

Ns»": 

Xp 

CÖ- 

Ifcl^ 

C6--. 

B^^ 

^NSiv.^ 

^^^v!^ 

^^m    c  ' 

1^    (kI 

MJX        CS 

W^  '^ 

W     NSv 

LSmt 


Fig.  308. 

Platychelys  obermlor/en,  Wagner.  Upper  Jura;  Kelheiiu,  Bavaria.  1/4-  -'>  Carapace.  ß,  Plastron.  BS, 
Brachial  shield  ;  Ep,  Epiplastron  ;  GS,  Gular  shiekl ;  Hpp,  Hypoplastron  ;  Hyp,  Hyoplastron  ;  IGS,  Interj^ular ; 
LS  i-iv,  Laterals  ;  Mp,  Mesoplastron  ;  MS,  Marginal ;  NS  i-v,  Neural  or  vertebral  shieMs  ;  SmS,  Supraniarginal ; 
Xp,  Xiphiplastron  ;  ci-8,'Costal  plates  e,  Entoplastron  ;-7!,i-8,  Neural  plates ;  rmdi,  Nuchal ;  py,  l^gal ;  x;  Pit 
for  attacliiiient  of  iliuni. 

finely  pitted  and  deeply  impressed  with  the  suture-lines  of  the  epidermal 
shields.  Neural  bones  moderately  elongated,  hexagonal,  with  their  antero- 
lateral  surfaces  short.  Mesoplastrals  well  developed,  meeting  in  the  middle 
line  ;  entoplastral  relatively  large  ;  xiphiplastrals  deeply  notched.  No  nuchal 
shield  ;  intergular  shield  not  divided ;  inframarginals  present.  Pectoral  arch 
resembling  that  of  the  existing  Chelys.     Upper  Jura  :  England. 

Platycheli/s,  AVagner  (Helemys,  Eüt.),  (Fig.  308).  Carapace  somewhat 
depressed,  with  a  iiumber  of  more  or  less  distinct  ridges  or  prominences  on  the 
neurals  and  costals.  Neurals  short  and  of  irregulär  contour,  the  width  usually 
much  exceeding  the  length.  Bridge  short.  Mesoplastrals  not  meeting  in  the 
middle  line.  Vertebral  shields  much  wider  than  long ;  nuchal  shield  present ; 
intergular  undivided.  No  articulation  between  pelvis  and  plastron  (Lydekker). 
Upper  Jura  ;  Bavaria,  France,  and  England.  [This  genus  is  included  by  von 
Zittel  with  the  Cheli/dridae.] 

Baena,  Leidy.  Intergular  shield  divided,  and  xiphiplastral  with  depressions 
which  appear  to  have  received  the  pubis  and  ischium.  Mesoplastrals  meeting 
at  the  middle  line,  but  with  the  median  ends  much  narrower  than  the  outer 
eiids.     Upper  Cretaceous  and  Eocene  ;  United  States. 


208  REPTILIA 


CLASS in 


Compsemys,  Leidy.  Known  by  nearly  all  parts  of  the  skeleton,  with 
characters  as  given  in  the  definition  of  the  sub-order.  Mesoplastron  complete, 
very  much  resembling  that  of  Pleurosternum.  Hinder  lobe  of  plastron  not 
notched.     Upper  Jura  ;  Rocky  Mountains. 

[Acknowledgments  are  due  to  Drs.  S.  W.  Williston,  E.  C.  Gase,  and  the  late  G.  Baur  for 
assistance  in  the  revision  and  extension  of  the  foregoing  chapter  on  Chelonia.  The  published 
writings  of  Baur,  Boulenger,  and  Lydekker  have  also  been  freely  drawn  upon.— Editok.] 

Order  7.     CROCODILIA.     {Eijdrosauria,  Lorkata.)  ^ 

Lizard-like  reptiles,  usually  of  large  size,  with  long,  keeled,  swimming  tau,  and 
entire  hody  covered  with  horny  scales,  underneath  which  along  the  hack  and  abdomen 
are  usually  rows  of  dermal  plates.  Investing  bones  of  temporal  region  contracting 
into  an  upyer  and  a  lower  arcade ;  quadrate  immovaUy  attached  to  the  skull; 
secondary  bony  palate  developed ;  parietal  foramen  wanting ;  teeth  deeply  socketed, 
confined  to  margin  of  jaws.  Vertebrae  amphiplatyan  or  procoelous,  and  among  the 
earlier  forms  amphicoelous.  Cervicals  with  short,  double -headed  ribs  attached  to 
centra ;  dorsal  ribs  long,  double-headed,  attached  to  transverse  processes.  Sternum 
ossified  ;  abdominal  ribs  present.  Sacrum  composed  of  two  vertebrae.  Two  pairs  of 
limbs  adapted  for  swimming  and  for  habitual  support  of  the  body. 

Crocodiles  possess  the  highest  internal  Organisation  known  amongst 
reptiles.  Their  general  form  resembles  that  of  lizards  and  Rhyncho- 
cephalians,  but  their  skeletal  structure  is  radically  different ;  while,  on  the 
other  band,  there  is  a  fundamental  resemblance  between  their  respiratory 
Organs  and  those  of  birds.  True  Crocodilians  are  apparently  initiated  in  the 
Lias,  and  their  subsequent  evolution  is  clearly  traceable,  but  their  predecessors 
in  the  Trias  (Parasuchia)  are  with  difficulty  distinguished  from  Rhyncho- 
cephalians  and  Dinosaurs. 

Sub-Order  1.     PARASUCHIA.     Huxley.^ 

Premaxillae  greatly  elongated.  External  nares  separate  and  placed  far  backward, 
in  proximity  to  the  small,  upwardly  directed  orbits ;  internal  nares  occupying  their 

^  Literature : 

Brühl,  C.  B.,  Das  Skelet  der  Krokodilien.  Vienna,  1862. — Dollo,  L.,  Premiere  note  sur  les 
Crocodiliens  de  Bernissart  (Bull.  Mus.  Koy.  d'Hist.  Nat.  Belg.  vol.  II.  p.  309),  1883. — Gray,  J.  E., 
Synopsis  of  the  species  of  recent  Crocodilians  (Trans.  Zool.  Soc.  vol.  VI.),  1862. — Huxley,  T.  H., 
Notes  on  the  specific  and  generic  characters  of  recent  Crocodilia  (Proc.  Linn.  Soc.  vol.  IV.  pt.  1), 
1860. — Koken,  E.,  Die  Dinosaurier,  Crocodilien  und  Sauropterygier  des  norddeutschen  Wealden 
(Palaeont.  Abhandl.  Dames  und  Kayser,  vol.  III.),  1887.— Die  Reptilien  der  norddeutschen  unteren 
Kreide  (Zeitschr.  deutsch.  geoL  Ges.  vol.  XXXV.  p.  792),  1883.— Ch(7e?i,  R.,  Monograph  of  the  fossil 
Reptilia  of  the  London  Clay  (Palaeontogr.  Soc),  1849-58. — Monograph  of  the  fossil  Reptilia  of  the 
Wealden  and  Purbeck  Forniations  {ibid.),  1853-64. — On  the  association  of  dwarf  Crocodiles  with  tlie 
diminutive  Mannnals  of  the  Purbeck  Shales  (Quar.  Journ.  Geol.  Soc.  vol.  XXXV.  p.  148),  1879. — 
Parker,  W.  K.,  On  the  structure  and  development  of  the  skull  in  the  Crocodilia  (Trans.  Zool.  Soc. 
vol.  XL),  1883. —  Woodtoard,  A.  S.,  On  the  literature  and  nomenclature  of  British  fossil  Crocodilia 
(Geol.  Mag.  [3],  vol.  IL  p.  496),  1885.— The  history  of  fossil  Crocoddes  (Proc.  GeoL  Assoc.  vol. 
IX.),  1886. 

'^  Literature : 

Cope,  E.  D.,  On  the  Reptilia  of  the  Triassic  Formations  of  the  Atlantic  Region  of  the  United 
States  (Proc.  Amer.  Phd.  Soc.  vol.  XL  p.  444),  1871.— Ibid.  vol.  XVIII.  (1878),  p.  21Z.— Huxley, 
T.  H.,  On  Stagonolepis  robertsoni,  and  on  the  evolution  of  the  Crocodilia  (Quar.  Journ.  Geol.  Soc. 
vol.  XXXL  p.  423),  1876.— Marsh,  0.  C,  On  Belodon,  etc.  (Amer.  Journ.  Sei.  [3],  vol.  L.  p.  487), 
1895.— J/eyer,  H.  von,  Ueber  Belodon,  etc.  (Palaeontogr.  vol.  X.  p.  227),  1863. 


ORDER  VII 


CROCODILIA 


209 


jyrimitire  position  on  either  siele  of  the  vomers.  Palatals  and  pterygoids  not  meeting 
in  the  middle  line.  Supratemporal  vacuities  very  small ;  lateral  vacuities  large,  cor)i- 
pletely  endosed.  Parietals  and  frontals  paired ;  postorbitals  distinä.  Teeth  with 
anterior  and  posterior  carinae.  Vertebrae  amphiplatyan.  Coracoid  short  and 
rounded ;  clavicles  presenf.  Fuhis,  ischium,  and  ilium  all  entering  the  irnperforate 
acetabiUum. 

The  Farasuchia  of  the  Trias  are  commonly  regarded  as  ancestors  of  the 
longirostrate  Crocodilians,  which  they  resemble  in  numerous  features,  such  as 


Pmx 


Belodon  kapß,  v,  Meyer.  Upper  Keuper  ;  Stuttgart,  Würteniberg.  Skull  from  superior  (A),  palatal  (B),  and 
lateral  (Q,  aspects,  1/7.  A,  Orbit ;  ang,  Angular  ;  art,  Articular ;  ho,  Basioccipital ;  ch,  Internal  nares ;  d, 
Dentary  ;  D,  Antorbital  vacuity  ;  D',  Mandibular  vacuity  ;  exo,  E\ocoipital ;  fr,  Frontal ;  ju,  Jugal ;  /,  I^achry- 
mal ;  vix,  Maxiila  ;  N,  External  narial  openings  ;  na,  Nasal ;  pa.  Parietal ;  pl,  Palatine  ;  pmx;  Premaxilla  ;  por. 
Postorbital ;  prf,  Prefrontal ;  pt,  Ptft-ygoid  ;  ptf,  Postfrontal ;  qu,  Quadrate  ;  quj,  Quadrato-jugal ;  S,  Lateral 
temporal  vacuity  ;  .S",  Suprateiiiporal  vacuity  ;  sry,  Squaniosal ;  vo,  Vomer. 

their  considerable  size,  armouring  of  the  trunk  region,  elongated  rostrum, 
coarsely  sculptured  cranial  plates,  Separation  of  the  lateral  temporal  vacuities 
from  the  orbits,  socketed  teeth,  structure  of  the  lower  jaw  (which  is  pierced 
in  its  hinder  half  by  a  vacuity),  and  prevalence  of  double-headed  ribs.  But 
in  addition  to  these  characters  they  possess  others  which  render  their  associa- 
tion  with  Dinosaurs  or  Rhynchocephalians  equally  justifiable.  Among  features 
they  share  in  common  with  Dinosaurs  may  be  mentioned  the  divided,  remotely 
VOL.  II  P 


210 


REPTILIA 


situated  external  nares,  large  aritorbital  vacuities,  form  of  the  pteiygoids  and 
basisplienoid,  and  the  upwardly  directed  transverse  processes  of  the  anterior 
dorsal  vertebrae.  With  the  Rhynchocephalians  they  agree  in  having  an  in- 
dependent  postorbital,  paired  parietals  and  frontals,  an  extensive  bony  palate, 
internal  nares  occupying  their  primitive  position  on  either  side  of  the  vomers, 
well-developed  abdominal  ribs,  and  a  similar  clavicle  and  coracoid.  The 
remaining  bones  of  the  pectoral  arch,  as  well  as  those  of  the  pelvic  girdle  and 
appendicular  skeleton,  are  intermediate  in  form  between  the  corresponding 
parts  of  modern  Crocodiles  and  Rhynchocephalians. 

The  Farasuchia  are  accordingly  to  be  regarded  as  a  collective  type  of  reptiles, 
from  which  the  crocodilian  stem  early  diverged  and  entered  upon  an  indepen- 
dent  course  of  evolution.  Parasuchian  remains  are  more  or  less  fragmentary, 
and  limited  to  the  Trias  of  Europe,  Asia,  and  North  America. 

Belodon,  v.  Meyer  {Phytosaurus,  Jaeger),  (Figs.  309,  310).  This  is  the  only 
accurately  known  genus,  and  is  represented   by  excellently  preserved  skulls, 

with  portions  of  the  skeleton  and 
dermal  armour,  in  the  Upper 
Keuper  of  Stuttgart.  It  is  about 
as  large  as  modern  crocodiles,  the 
skull  attaining  a  length  of  0'7  m. 
External  cranial  bones  pitted  and 
rugose  ;  lateral  eustachian  passages 
occupying  open  grooves  on  the 
basisphenoid ;  secondary  palate 
not  developed.  Dorsal  armour 
consisting  of  two  longitudinal  rows 
of  large,  overlapping  keeled  scutes 
with  coarse  ornamentation ;  sides  and  abdomen  covered  with  smaller,  more 
irregulär  scutes.  Detached  teeth  not  uncommon  in  the  Keuper  of  Würteni- 
berg  and  Franconia.  Fragmentary 
remains  also  known  from  the  Trias 
of  North  Carolina,  Pennsylvania, 
Connecticut,  New  Mexico,  Arizona, 
and  Utah. 

Stagonolepis,  Agassiz.  Similar  to 
Belodon,  but  teeth  with  tumid  base. 
Ventral  armour  consisting  of  from 
five  to  eight  rows  of  rectangular 
scutes.     Elgin  Trias. 

Parasuchus,     Huxley ;      Episcopo- 
saurus,    Cope.     These   are   imperfectly  known 
Grondwana  Formation  of  Maleri,  India,  and  the 
Trias. 

?  Psephoderma,  v.  Meyer  (Fig.  311).  Known  by  fragments  of  dermal 
armour  from  the  Alpine  Upper  Trias,  and  formerly  referred  to  Chelonians 
( Dermochelydidae) . 


Fig.  310. 

Belodon  kapß,  v.  Meyer.     Upper  Keuper ;  Würtenibei 
Dorsal  scute,  1/3  (after  H.  v.  Meyer). 


qMP' 


Fig.  311. 
PsephodeniKt  alphia,   v.   Meyer.     Uppei 


polding, 
Meyer). 


Bavaria.      Ventral    armour,    J/4 


Trias 
(alter 


Uuh- 
H.   V. 


genera,   the   former   from   the 
latter  from  the  New  Mexican 


ORDER  VII  CROCODILIA  211 

Sub-Order  2.     PSEUDOSUCHIA.     Zittel.i 

Premaxillae  reduced ;  nasals  very  large.  External  nares  paired,  placed  far 
forwards  ;  internal  nares  separate,  in  about  the  middle  of  the  palate.  Orbits  large^ 
laterally  direded.  Parietal  s  and  front  als  paired  ;  postorbital  distind.  Teeth  conical, 
deeply  socketed,  confined  to  anterurr  half  of  the  jaws.  Vertebrae  arnphiplatyan ; 
cervical  ribs  hatdiet-shaped,  double -headed.  Fore-limb  slightly  shorter  than  the 
posterior  ;  fifth  digit  of  pes  reduced,  comprising  but  a  single  phalanx.  Dorsal  armour 
consisting  of  a  paired  series  of  oblong  scutes. 

Aäosaurus,  Fraas  (Fig.  312).  Body  lizard-like,  longicaudate,  with  dorsal 
and  ventral  armouring  of  radially  ornamented  scutes ;  ventral  scutes  smaller 
than   the  dorsal,  and  almost  Square.     Skull   triangulär,  acuminate  in  front. 


Fig.  312. 

Artomurus  ferrutus,  Fraas.     Upper  Keuper  ;  Heslach,  near  Stuttgart.     Head  and  anterior  jxirtion  of  trank,  ^U. 
J,  Orbit ;  D,  Anturbital  vacnity  ;  N,  Narial  opening  ;  S,  lateral  temporal  vacuity  (alter  ( ).  Fraas). 

Antorbital  vacuities  large,  separated  from  the  large  external  nares  by  a  narrow 
ascending  process  of  the  maxilla.  Posterior  border  of  the  orbits  formed  by 
the  postfrontal  and  postorbital,  the  inferior  border  by  the  jugal.  Parietals 
and  frontals  similar  in  form  and  size.  Temporal  region  imperfectly  known. 
Mandibular  rami  pierced  by  a  large  foramen  between  the  articular  and  angular. 
Interclavicle  blade-like.  Twenty-four  complete  but  slightly  crushed  in- 
dividuals  are  preserved  in  the  Stuttgart  Museum,  all  on  a  single  slab  of 
Stuben  Sandstone  (Upper  Keuper),  from  Heslach,  near  Stuttgart.  The  largest 
of  these  has  a  total  length  of  86  cm. 

Dyoplax,  Fraas.  Upper  Keuper ;  Stuttgart.  Typothorax,  Cope.  Trias ; 
New  Mexico. 

Ornithosiichus,  Newton.  Skull  pointed  in  front,  very  simihir  to  Actusaurus. 
Orbits  large,  supratemporal  vacuities  small,  the  lateral  ones  triangulär.  Teeth 
slightly  recurved,  with  finely  serrated  anterior  and  posterior  cutting  edges. 
V'^ertebral  centra  elongated,  with  very  stout  neural  spines.  Ilium  elongated, 
ischium  slender,  pubis  long  and  rod-like.     Elgin  Trias.     0.  icoodwardi,  Newton. 

E rpetosaurus,  Newton.  Skull  narrov/  and  rounded  in  front.  Orbits  sub- 
elliptical,  directed  upwards  and  forwards.     Supratemporal  vacuities  round,  the 

^  Literat  are  : 

Fraas,  0.,  Ueber  Dyoi>lax  areiiaceus  (Wiirtt.  Jaliresh.  vol.  XXIII.),  1867.^Aetosaurus  ferratus 
{ihül.  vol.  XXXIII.),  1877.— Newton,  E.  T.,  Reptiles  from  the  Elgin  Sandstone  (Phil.  Trans,  vol. 
CLXXXV.),  1894. 


212  KEPTILIA 

lateral  ones  triangulär,  and  antorbital  opening  long  and  narrow.  External 
nares  small ;  interclavicle  blade-like  ;  dorsal  scutes  coarsely  sculptured.  Elgin 
Trias;  Scotland. 

Sub-Order  3.     MESOSUCHIA.     Huxley.i 

Snoiit  greatly  elongated  in  the  earlier  forms,  short  and  hroad  in  some  of  the  later. 
External  nares  unpaired  and  terminal ;  internal  nares  confluent,  opening  at  posterior 
margin  of  the  secondary  palate  formed  hy  plates  of  the  maxillae  and  palatines,  there 
heing  no  outgrowths  from  the  pterygoids.  Eustachian  passages  open  grooves  on  the 
hasisphenoid.  Parietal  and  frontal  unpaired.  Vertebrae  amphicoelous,  or  more 
rarely  amphiplatyan.  Clavicular  elements  wanting.  Coracoid  elongated,  with  slight 
perfm^ation.  Pubis  excluded  from  acetabulum,  and  borne  on  an  anterior  process  of  the 
ischium.     Anterior  extremities  pentadadylate  ;  fifth  digit  of  pes  rudimentary. 

The  Mesosuchia,  which  comprise  all  the  Jurassic  and  a  few  Lower  Creta- 
ceous  crocodiles,  were  separated  by  Huxley  from  the  later  Eusuchia  chiefly  on 
account  of  differences  in  the  palate,  eustachian  passages,  and  vertebral  centra. 
In  the  present  group  the  pterygoids  do  not  develop  secondary  plates  to 
prolong  the  canal  of  the  nares,  which  opens  at  the  hinder  margin  of  the 
palatines ;  the  eustachian  canals  are  not  closed ;  and  the  vertebrae  in  all  but 
the  latest  forms  are  amphicoelous.  Like  the  typical  Cretaceous  and  modern 
families,  the  Mesosuchia  comprise  both  long-snouted  and  broad-snouted  croco- 
diles, the  latter,  however,  not  appearing  until  the  Purbeckian.  All  except  the 
latest  forms  are  adapted  for  an  exclusively  aquatic  life,  and  are  known  from 
Europe,,Madagascar,  Patagonia,  and  perhaps  North  America. 

Section  1.     LoNGiROSTRES.     Lydekker. 

Snout  greatly  p'oduced.  Nasals,  as  a  rule,  not  reaching  the  premaxillae  and 
external  iwstril.  Mandibular  rami  united  in  a  long  Symphysis  formed  by  the  dentary 
and  splenial.      Vertebrae  amphicoelous. 

Family  1.     Teleosauridae.     Zittel. 

Teeth  conical,  slender,  closely  set.  Orbits  entirely  enclosed,  superioriy  or  more 
rarely  laterally  directed,  and  notably  smaller  than  the  subrectangular  supratemporal 
vacuities.  Prefrontals  small,  lachrymals  well  developed.  Antorbital  mcuities  small, 
laterally  placed.  Anterior  limb  only  about  half  as  long  as  the  hinder  pair.  Dorsal 
armour  consisting  of  a  paired  series  of  broad,  overlapping  plates;  ventral  plates 
suturally  united,  forming  several  more  or  less  irregulär  series,  or  a  mosaic  of  small 
polygonal  scutes.     Jura. 

^  Literature : 

d' Alton,  M.,  Sind  Burmeister,  IL,  Der  fossile  Gaviale  vou  Boll,  Halle,  1854. — Bronn,  H.  G., 
aud  Kaup,  J.  J.,  Ueber  die  gavialartigen  Reptilien  der  Liasformation.  Stuttgart,  1841. — Dollo,  L., 
Premiere  note  sur  les  Crocodiliens  de  Bernissart  (Bull.  Mus.  Roy.  d'Hist.  Nat.  Belg.  vol.  II.  p.  309), 
1883. — Deslangchamps,  E.  E.,  Notes  paleontologiques.  Caen  and  Paris,  1863-69. — Le  Jura  Nor- 
mand.  Caen  and  Paris,  1877-78.  —  Deslongchamps,  J.  A.  E.,  Memoir  sur  les  Teleosauriens  de 
l'epoque  jurassique  (Mem.  Soc.  Linn.  Norm.  vol.  XIII.),  1863. — Fraas,  E.,  Die  Meerkrokodile 
(Württ.  naturw.  Jahresh.,  vol.  LYII.  p.  409),  1901.— Palaeontogr.  vol.  XLIX.  pp.  1-72,  1902.— 
Ilulke,  .T.  W.,  Skeletal  Anatoniy  of  the  Mesosuchia  (Proc.  Zool.  Soc.  London,  pt.  4),  1888. — 
Koken,  E.,  Thoracosaurus  macrorhynchus  BL,  aus  der  Tuffkreide  von  Maestricht  (Zeitschr.  deutsch. 
geol.  Ges.  vol.  XL.  p.  754),  1888. — hortet,  L.,  Les  Reptiles  fossiles  du  Bassin  du  Rhone  (Arch. 
Mus.  d'Hist.  Nat.  Lyon,  vol.  V.),  1892. — Sauvage,  E.,  Memoir  sur  les  Dinosaurs  et  les  Crocodiliens 
des  terrains  jurassiques  de  Boulogne-sur-Mer  (Mem.  Soc.  Geol.  France  [2],  vol.  X.),  1874. —  Winckler, 
T.  C,  Etüde  sur  le  genre  Mystriosaurus  (Arch.  Mus.  Tylere,  vol.  IV.  pt.  1),  1876. 


ORDER  VII 


CROCODILIA 


213 


The  members  of  this  family  closely  reserable  modern  gavials  in  size  and 
general  appearance,  except  that  they  have  smaller  heads 
and  more  weakly  developed  fore-limbs.  The  principal 
differences  are  to  be  found  in  the  characters  of  the  palate, 
eustachian  passages,  vertebral  centra,  ventral  armour,  and 
absence  of  hypapophyses  in  the  cervical  region. 

Mysfriosaurus,  Kaiip.     Skull  attaining  a  length  of  1  m., 
and  total  length  upwards  of  6  m.     Snout 
gradually    tapering ;    orbits     superiorly  fkj.  313. 

directed.     Teeth  implanted  nearly  ver-      Peiagomums  temp<yraiis, 

,-,  .,,  ,       .  1  ,       .         Blv.    sp.      Upper    Lias ; 

tically,  with  anterior  and  posterior  Curcy,  Calvados.  Pos- 
carinae.  Known  by  complete  skeletons  \^l^f£^^; 
from   the   Upper   Lias  of  Würtemberg,   P^iate,  1/2-    ho,  Basioc- 

.  ^^  11  r      7    77        •       cipital ;  c7i,  Internal  nares ; 

r  rancoma,  and  Jingland.  M.  ooUensts,  j,  Jugai ;  nu-,  Maxiiia ;  ^77, 
Cuvier ;  31.  chapmani,  König.  f?^  Quadrate!  .^^^^^^''^'^ ' 


Fio.  314. 
Teleosauruscadomensis,Cn\\e.r!i\).  Bathon  ian  ;  Caen,  Calvados.  .-1,  Palatal;  /J,  Lateral ;  C,  Superior  asi>ects 
of  skull.  D,  Mandible.  J,  Orbit ;  o/tj/,  Angular ;  ort,  Articular;  ^o,  Basioccipital ;  hspÄ,  Basisphenoid  ;  ch, 
Internal  nares  ;  D,  Mandibular  vacuity  ;  d,  üentary  ;  //•,  Frontal ;  la,  Lachrynial ;  mx,  Maxiila  ;  na,  Na.sal ;  op, 
Splenial ;  pa.  Parietal ;  pl,  Palatine ;  jnnx,  Preniaxilla ;  pr/.  Prefrontal ;  qv,  Qua<lrate ;  fpij,  Quadrato-jugal ; 
S,  Suprateniporal  vacuity  ;  S',  Lateral  temporal  vacuity  ;  sq,  Squainosal :  t,  Transverse  (ectopterygoid) ;  x,  Sur- 
augular  (after  E.  üeslongchanips). 


214 


REPTILIA 


CLASS  III 


Felagosaurus,  Bronn  (Fig.  313).  Like  the  preceding,  but  much  smaller, 
the  snout  tapering  more  gradually,  and  orbits  laterally  directed.  Antorbital 
vacuity  much  reduced  or  absent;  suborbital  vacuity  in  the  palate  large ; 
posterior  narial  opening  of  pyriform  outline.  P.  fj/pus,  Bronn,  about  1  m.  in 
length ;  some  species  2  m.     Upper  Lias  of  Southern  Germany  and  France. 

Steneosaurus,  GeofF.  {Sericodon,  v.  Meyer).  Differs  from  Mystriosaurus  in 
having  the  posterior  narial  opening  rounded,  palatines  more  expanded,  and 
frontal  small.      Upper  Lias  to  Kimmeridgian. 

Teleosaurus,  Geoff.  (Figs.  314,  315).  Skull  much  elongated  and  narrow ; 
snout  flattened,  thin,  with  rectilinear  edges ;  teeth  curved   outwards ;  orbits 


Fig.  315. 

Teleosaurus  cadomensis,  Cuvier  sp.     ßatlioriian  ;  Noriimiidy. 
Portion  of  dorsal  (A),  and  ventral  (ß)  armour  (restored  after  E.  Deslongcliamps). 

circular,  superiorly  directed.  Dorsal  scutes  longitudinally  keeled  in  sacral  and^ 
caudal  regions ;  ventral  armour  extending  between  the  limb  girdles.  LowerJ 
Middle,  and  Upper  Jura.     T.  cadomensis,  Geofi'. 

Aeolodon,  v.  Meyer  ;  Crocodileimus,  Jourdan  ;  Teleidosaurus,  Deslong.     Upp< 
Jura. 


Family  2.     Metriorhynchidae.     Zittel.     {Thalaftosuchia,  Fraas.) 

Orbits  entirely  endosed,  elongated,  laterally  placed,   with  sderofic   ring.      Pre- 
frontals  large;   nasals  broad,  widening  the  snout  region  posteriorly ;   lachrymals 


ORDER  Vir  CROCODILIA  215 

reduced.     Supratempm'al  vacuities  very  large.     Dermal  armour  completely  obsolete  ; 
limbs  paddle-shaped.     Middle  and  Upper  Jura. 

Metriorhynchus,  v.  Meyer.  Skull  elongated  and  tapering,  feebly  sculptured. 
Prefrontals  unusually  large  and  forming  an  overhanging  ledge  above  the  orbits. 
External  nostril  large,  upwardly  directed  ;  teeth  slender,  carinated,  and  slightly 
curved,  twenty  to  twenty-seven  present  on  either  side  of  the  jaws  above  and 
below ;  three  or  four  anterior  teeth  enlarged.  Fore-limbs  much  smaller  than 
the  hinder  pair.     Middle  Jura.     France  and  England. 

Geosaurus,  Cuvier  (Cricosaurus,  Wagner ;  lihacheosaurus,  von  Meyer). 
Lithographie  Stone ;  Bavaria.  Siichodus,  Lydekker.  Oxford ian  ;  England. 
Plesiosuchus,  Owen.     Kimmeridgian  ;  Dorsetshire. 

Dakosaurus,  Quenst.  Skull  comparatively  short  and  broad  ;  nasals  reach- 
ing  the  premaxillae ;  snout  compressed  and  rounded  in  front.  Teeth  large, 
slightly  curved,  oval  in  section,  smooth,  with  anterior  and  posterior  carinae  : 
about  twenty  on  each  side  of  the  jaw  above  and  below.  External  cranial 
bones  smooth  or  feebly  sculptured ;  mandibular  rami  without  lateral  vacuity. 
Middle  and  Upper  Jura ;  Swabia  and  Bavaria.  Kimmeridgian ;  England. 
A  complete  skeleton  of  D.  maximus,  Quenst.,  4  m.  long,  preserved  in  the 
Stuttgart  Museum. 

Family  3.     Pholidosauridae. 

Siiout  long  and  narrow,  passing  ahruptly  into  the  facial  region.  Orbits  oval, 
laterally  placed,  almost  as  large  as  the  supra temporal  vacuities,  and  confluent  with  the 
lateral  temporal  fossae.  Nasals  long  and  narrow,  reaching  the  posterior  tip  of  the 
elongated  preinaxillae.  Prefrontals  of  moderate  size.  Internal  narial  opening 
bor  der  ed  laterally  by  the  pterygoids.     Dorsal  aml  ventral  armour  present. 

The  members  of  this  family  are  known  only  from  fresh-water  deposits  of 
the  Purbeckian,  Wealden,  and  Lower  Cretaceous. 

Pholidosaurus,  v.  Meyer  {Macrorhynchus,  Dunker).  Teeth  round  or  oval  in 
section,  longitudinally  striated,  in  uniform  series  of  about  thirty  on  each  side 
in  either  jaw.  Wealden  of  England  and  Neocomian  (Hils  Sandstone)  of 
Hanover. 

Petrosuchus,  Owen.  Like  the  preceding,  but  internal  narial  opening 
enclosed  by  the  palatines.     Purbeckian  ;  Dorsetshire. 

Hylaeochampsa,  Owen.     Imperfectly  known.     Wealden  ;  England. 

Section  2.     Brevirostres.     Lydekker. 

Snout  short,  broad,  and  rounded.  Nasals  usually  reaching  the  p-emaxillae  and 
external  nostril.  Dentary  alone  forming  the  shmi  Symphysis  of  lower  jaw ;  teeth 
irregidar  in  size  and  shape.      Vertebrae  amphicoelous. 

Family  1.     Atoposauridae. 

Small,  lizard-like  crocodiles  with  broad,  triangulär  shulls.  Orbits  much  larger 
than  supratemporal  vacuities.  Dorsal  armour  consisting  of  a  paired  longitudinal 
series  of  oblong  plates.     No  ventral  armour  observed.     Upper  Jura. 

Alligatorium,  Jourdan.  Total  length  about  40  cm.  External  cranial 
bones  coarsely  sculptured;  bind -limbs  longer  and  more  robust  than  the 
anterior  pair. "  Lithographie  Stone  ;  Cerin,  France,  and  Bavaria. 


216 


EEPTILIA 


CLASS  III 


Alligaforellus,  Jourdan  (Fig.  316).     Total  length   22   cm.     Cranial  bones 
f^intly  sculptured.     Nasals  elongated,  and  apparently  dividing  the  external 


Fig.  316. 
Alligator ellus  heaumonti,  Jourdan.     Upper  Jura  ;  Ceriu.  Aiii,  France,     i/o. 

nares.     Tail  very  long ;  at  least  thirty  caudals.     Lithographie  Stone  ;  Cerin, 
France. 

Atoposaurus,  v.  Meyer.  Tail  very  long,  comprising  over  fifty  caudals. 
Dorsal  armour  not  observed.  Otherwise  like  the  preceding.  Lithographie 
Stone ;  Cerin,  France,  and  Bavaria. 


Family  2.     Goniopholidae.     {Metamosuchia,  Hulke.) 

Small  to  large-sized  crocodiles.  Orbits  usually  smaller  than  supratemporal 
vacuities.  Internal  narial  opening  remote,  at  hinder  margin  of  palatines,  and 
bounded  in  pari  hy  the  ptenjgoids.  Dorsal  armour  comprising 
two  or  more  longitudinal  series  of  overlapping  and  sometimes 
articulating  scutes.  Ventral  scutes  suturally  wiited.  Pur- 
beckian  and  Wealden. 

Goniopholis,  Owen  {Diplosaurus,  Marsh ;  Amphicotylus, 
Hyposaurus,  Cope),  (Fig.  317).  Snout  moderately  long, 
nasals  not  quite  reaching  external  nostril ;  supratemporal 
vacuities  larger  than  the  orbits.  Twenty-three  stout 
teeth  on  each  side  of  either  jaw,  carinated  and  vertically 
grooved.  Ventral  armour  consisting  of  seven  to  ten 
longitudinal  series  of  polygonal  plates  united  by  jagged 
sutures.  Skull  in  some  species  attaining  a  length  of 
70  cm.  G.  simus,  Owen,  known  by  complete  skeletons 
Fig.  317.  about  2  m.  long,  has  limbs  of  equal  size.     Purbeckian 

Goniopholis  simus,  Owen,   and  Wealden  ;  England,  Belerium,  and  Northern  Germany. 

Purbeckian ;  Swanage,  Dor-    _^  t  r>(    i  i 

setshire.     Posterior  portion     U  pper  J  Ura  ;    üolorado. 

cl^päteViorna^fs'nrPaii:  Bemissartia,   Dollo.      Attaining    a    length    of    1    m. 

itiLf'  ^^^^^^'^'^ '('*^^'^''   Supratemporal  vacuities  smaller  than  the  orbits,  nasals 
not   reaching    the   external    nostril.       Twenty   irregulär 
teeth  on  each  side  of  either  jaw  ;  fore-limbs  much  shorter  than  the  hinder 
pair.       Dorsal    armour    with    more    than    two    longitudinal    series    of    over- 


ORDER  VII 


CROCODILIA 


217 


lapping  scutes ;    ventral   scutes  also  overlapping.      Wealden ;    Belgium.     B 
fagesi,  Dollo. 

Machimosaurus,  v.  Meyer  (Fig.  318).  Imperfectly  known. 
Teeth  obtusely  conical,  strongly  striated.     Upper  Jura. 

Nannosuchus,  Owen.  Dwarf  crocodiles  similar  to  Gonio- 
pholis,  but  with  slender,  curved,  smooth,  and  more  uniform 
teeth.     Skull  about  10  cm.  long.     Purbeckian ;  Dorsetshire. 

T/ieriosiichus,  Owen.  Total  length  less  than  0'5  m. 
General  form  approaching  that  of  modern  crocodiles. 
Supra temporal  vacuities  smaller  than  the  orbits ;  teeth 
tumid  and  very  irregulär ;  mandibular  Symphysis  short. 
Dorsal  scutes  overlapping  and  also  united  at  their  outer 
angles  by  peg-and-socket  articulations ;  ventral  scutes 
polygonal,  united  by  sutures  only.  Purbeckian ;  Dorset- 
shire.    T.  pusillus,  Owen. 


Fig.  318. 

Machiniosanrus  hngi, 
V.  Meyer.  Kinimeriil- 
gian;  Lindnerberg, 
near  Hanover.    i/]. 


Sub-Order  4.     EUSUCHIA.     Huxley.i 

Snout  produced  in  some  forms,  but  more  commonly  broad  and  short.  External 
nostril  unpaired  and  terminal ;  internal  nasal  passage  prolonged  and  fioored  by  the 
greatly  developed  secondary  palate,  formed  by  plates  fr  am  the  maxillae,  palatines, 
and  pterygoids.  Eustachian  canals  completely  enclosed  ;  vertebrae  mostly  pti'ocoelous. 
Other  charaders  as  in  Mesosuchia. 

This  group  comprises  the  later  Cretaceous,  Tertiary,  and  modern  croco- 
diles, among  which  are  some  long-snouted  forms,  but  the  greater  number  are 
of  the  broad-snouted  type.  As  already  indicated,  they  differ  from  the  Jurassic 
Mesosuchia  chiefly  in  the  characters  of  the  palate,  eustachian  canals,  and  verte- 
bral  centra,  but  as  to  their  genetic  relations  Palaeontology 
afFords  no  precise  Information. 

A  dorsal  armour  of  bony  scutes  overlaid  by  the 
corneous  epidermis  is  always  present  among  Eusuchia,  and 
frequently  also  a  ventral  armour.  The  dorsal  scutes  are 
externally  pitted,  more  rarely  radially  sculptured,  and  are 
often  longitudinally  keeled.  The  ventral  scutes  are 
flattened,  keelless,  less  prominently  sculptured,  and  some- 
times  divided  (Fig.  319). 

The  vertebral  column  comprises  about  twenty-five  pre- 
sacral  vertebrae,  two  sacrals,  and  at  least  thirty-five  caudals. 
Recent  crocodiles  have  all  the  presacral  vertebrae  except 
the  atlas  and  axis  procoelous,  and  the  sacrals  and  anterior 
caudals  amphiplatyan.  There  are  about  nine  cervicals.  The  atlas  (Fig.  320) 
is  quadripartite,  and  its  unpaired  ventral  piece  (x)  has  been  variously 
interpreted  as  the  centrum,  intercentrum,  or  hypapophysis.  The  paired 
lateral  elements  are  roofed  by  a  median  dorsal  piece  which  abuts  against  the 

^  Literature  : 

Licdivig,  R.,  Fossile  Krokodilieu  aus  der  Tertiarfonnation  des  Mainzer  Beckens  (Palaeontogr. 
Supplem.  vol.  III.),  1877. — Lydekker,  R.,  Siwalik  Crocodilia,  etc.  (Pal.  Indica,  ser.  X.  vol.  III. 
p.  209),  1886. —  Vaillant,  L.,  i^tudes  zoologiques  sur  les  Crocodiliens  fossiles  du  tertiäres  (Ann.  Soc. 
Geol.  vol.  III.),  1872. —  Woodtvard,  A.  S.,  On  the  literature  and  nonienclature  of  British  fossil 
Crocodiles  (Geol.  Mag.  [3],  vol.  II.  p.  496),  1885.— The  history  of  fossil  Crocodiles  (Proc.  Geol. 
Assoc.  vol.  IX.),  1886. 


Fig.  319. 

Divided  ventral  seute 
of  Diiüocynodon,  sp.  Oli- 
gocene ;.  Eiirope. 


218 


EEPTILIA 


CLASS  III 


Fig.  320. 

Crocodüus  vulgaris,  Cav.  Receiit ;  Egypt.  Anterior 
cervical  vertebrae,  I-IV,  n,  Lateral  piece  of  atlas  ;  pod, 
Odoiitoid  process  (=centrum  of  atlas);  'pr,  Proatlas  ;  ri-H, 
Cervical  ribs  ;  x.  Basal  piece  of  atlas  (  =  intercentrum). 


basiocciput  and  represents  a  rudimentary  proatlas.     The  basal  piece  Supports 
a  pair  of   styliform,   single-headed   ribs,  directed   downward   and   backward. 

Properly  speaking  the  atlantal 
centrum  is  represented  by  the 
odontoid  process  of  the  axis.  The 
seven  succeeding  cervicals  bear 
strong  neural  spines,  transverse 
processes,  zygapophyses,  parapo- 
physes,  and  frequently  also  ventral 
keels  or  true  hypapophyses.  The 
ribs  borne  by  these  vertebrae  are 
all  short,  hatchet  -  shaped,  and 
double-headed.  In  the  first  two 
dorsal  vertebrae  the  parapophyses 
and  transverse  processes  are  separ- 
ated  by  a  narrow  interspace,  and 
the  latter  become  more  elongated, 
passing  posteriorly  (caudal).  The 
parapophyses  gradually  ascend, 
passing  on  to  the  neural  arch  in  the  third  dorsal  vertebra,  and  thereafter 
both  articular  facettes  for  the  double-headed  ribs  are  borne  by  the  transverse 
processes.  These  facettes  continue  to  approximate,  and  finally  become 
merged  with  each  other  in  the  posterior  dorsal  vertebrae,  so  that  the  last 
rib  is  single-headed.  The  lumbars,  of  which  there  are  from  four  to  six, 
have  well-developed  transverse  processes,  but  are  non-costiferous.  The  short 
and  stout  sacral  ribs  are  as  a  rule  distally  expanded,  and  suturally  united  to 
their  centra  and  neural  arches.  The  vertebrae  of  the  anterior  half  of  the  tail 
bear  moderately  developed  transverse  processes,  attached  like  the  sacral  ribs  to 
the  neuro-central  sutures.  All  except  the  anterior  and  a  few  of  the  posterior 
caudals  bear  chevron  bones. 

The  first  and  second  pairs  of  dorsal  ribs  are  attached  to  the  sternum,  which 
is  a  large,  rhomboidal,  cartilaginous  plate  lying  immediately  below  and 
behind  the  interclavicle  (episternum).  The  succeeding  five  to  seven  pairs 
are  connected  by  means  of  sternal  ribs  with  the  so-called  abdominal  sternum. 
The  sternal  ribs  are  followed  by  seven  pairs  of  abdominal  ribs,  of  which  the 
posterior  is  the  most  strongly  developed,  and  unites  with  the  pubic  cartilage. 
Cartilaginous  uncinate  processes  are  borne  by  the  dorsal  ribs. 

The  external  cranial  bones  are  almost  always  coarsely  sculptured.  The 
oval  or  rounded  orbits,  which  in  the  preceding  sub- Orders  are  invariably 
enclosed  by  bone,  are  here  confluent  with  the  lateral  temporal  vacuities.  The 
size  of  the  latter  is  usually  in  inverse  proportion  to  that  of  the  supratemporal 
vacuities,  and  the  latter  as  a  rule  are  smaller  than  the  orbits.  The  parietal 
and  frontal  are  unpaired  in  the  adult  condition,  and  there  is  never  a  parietal 
foramen.  The  squamosal  is  a  triangulär  bone  forming  the  postero-external 
border  of  the  supratemporal  vacuity.  Postfrontals,  prefrontals,  and  lachrymals 
are  all  variable  in  size.  The  nasals  are  long,  triangulär  bones,  usually  reaching 
the  premaxillae,  and  sometimes  even  the  external  nostril  in  front,  and  applied 
against  the  acute  median  process  of  the  frontal  posteriorly.  The  nostril 
opening  is  undivided,  terminal,  and  enclosed  by  the  short,  paired  premaxillae. 
The  quadrate  is  broad  and  immovably  united  with  the  surrounding  Clements. 


ORDER  VII 


CEOCODILIA 


219 


The  under  side  of  the  skull  is  characterised  by  a  great  development  of  the 
secondary  palate,  formed  by  horizontal  expansions  of  the  premaxillae,  maxillae, 
palatines,  and  pterygoids,  and  pierced  by  a  moderate  or  large-sized  infraorbital 
vacuity.  This  extensive  roofing  of  the  buccal  cavity  conceals  the  voraers  and 
causes  the  internal  opening  of  the  nasal  passage  to  be  displaced  far  backwards, 
at  the  posterior  border  of  the  pterygoids,  whereas  in 
the  Mesosuchia  the  opening  is  never  further  remote 
than  the  hinder  margin  of  the  palatine  plates  (cf. 
Fig.  313  with  Fig.  321).  A  transverse  bone  (ecto- 
pterygoid)  is  present,  connecting  the  pterygoids 
with  the  maxillae  and  jugal  (Fig.  321,  T).  Modern 
gavials  exhibit  in  the  adult  a  pair  of  bulbous  out- 
growths  {hu)  of  the  palatines  which  communicate 
with  the  nasal  passage  and  function  as  air-reservoirs. 

The  mandibular  ramus  is  composed  of  the  usual 
six  pieces,  one  of  which,  the  articular,  is  pneumatic. 
A  large  foramen  communicating  with  the  inner 
cavity  of  the  jaw  is  almost  invariably  present 
between  the  angular,  surangular,  and  dentary.  Gdviaiis  gangeticus,  Geoffr. 
The  Symphysis  is  formed  by  the  latter  element  «--t^^  ]^^-^^  Sii'EwinI' 
alone  in  the  broad-nosed  forms,  by  the  dentary  and  eusuchian  secondary  paiate.    bo, 

,       .    -    ,  ,  .  1       1  •        .       ^  •  Basioccipital  ;      bu,    Ossified    air- 

splenial  tOgether  among  the  longirOStrate  Species.  Chambers ;  ch,  Posterior  nares ;  j, 

Numerous  conical  teeth  of  oval  or  circular  cross-  'j^^ilj;'^oiäf^:&J.^^^^^^ 
section,  smooth  or  striated,  and  frequently  carinated,   Ectopterygoid ;  a;,  dpening of  eusta- 

'  •,.,  iTi  1  •         £    chiaii  cauals. 

are  implanted  m  deep  alveoli  along  the  margin  oi 

the  jaws.     They  are  often  irregulär  in  form  and  size,  but  their  number  remains 

constant  for  particular 
species,  and  in  many  cases 
also  for  the  genus. 

In  the  pectoral  arch 
clavicles  are  wanting.  The 
scapula  is  elongated  and 
expanded  at  either  end, 
as  is  also  the  coracoid. 
The  latter  is  thickened  in 
its  proximal  portion,  and 
pierced  by  a  round  fora- 
men. The  humerus  is 
stout,  slightly  curved,  and 
exhibits  near  the  head  a 
conspicuous  process  as 
well  as  a  deltoid  crest.  Its  distal  end  is  furnished  with  two 
facettes  for  the  bones  of  the  second  segment,  of  which  the 
ulna  is  generally  somewhat  the  longer  (Fig.  323).  The 
proximal  row  of  the  carpus  contains  two  elongated  elements  ^.^^^^  fore-umb  of 
(radiale  and  ulnare,  both  constricted  in  the  middle),  and  a  <^yoc^;^^.  J^R^^j^"^- 
small  pisif orme  to  which  the  fif th  metacarpal  is  attached  by  eaVpais ;  V,  Pisiforme ; 
ligaments.  The  two  radial  digits  are  slightly  stouter  than  jL^^i^gltV'  ^^"*''''' 
the  three  ulnar.  .     . 

Of  the  three  elements  of  the  pelvic  arch  (Fig.  322),  the  pubis  is  excluded 


Pelvis  of  Crocodile. 
(7,  llium  ;  is,  Iscliium ;  pv,  Pubis. 


Flfi.  323. 


220 


REPTILIA 


CLASS  III 


from  the  acetabuluni,  and  borne  on  a  prominent  anterior  process  of  the 
ischium.  The  pubis  is  more  or  less  spatula-shaped  ;  the  ischium  resembles  the 
scapula;  and  the  ilium  is  a  strong  bone  with  curved  upper  margin,  and 
extended  antero-posteriorly.  Its  enlarged  anterior  portion  is  attached  to  the 
sacral  ribs.  The  femur  is  longer  and  more  slender  than  the  humerus,  and 
without  an  inner  trochanter ;  tibia  and  fibula  are  of  about  equal  proportions. 
There  are  two  rather  large  proximal  tarsals,  a  calcaneum  (fibulare)  and 
astragalo-scaphoid,  the  latter  representing  the  coössified  tibiale,  centrale,  and 
intermedium.  Two  bones  are  likewise  present  in  the  distal  row,  of  which  the 
cuboid  is  the  larger,  and  supports  the  third,  fourth,  and  the  rudimentary  fifth 
metatarsal.  The  three  inner  digits  of  both  pes  and  manus  are  provided 
with  claws. 

A  longirostrate  section  of  JEusuchia  is  constituted  by  the  gavials,  which 
correspond  to  the  mesosuchian  Teleosaurs,  and  may  possibly  have  been 
descended  from  them.     Modern  crocodiles  and  alligators  form  the  brevirostrate 

section,    but    between    these    types    are    some 
annectant  fossil  forms,  such  as  Tomistoma,  etc. 

Family  1. 
Tomistomidae.      {Rhynchosuchidae,  Hiixley.) 

Snout  much  produced,  passing  gradually  info  the 
facial  region.  Nasals  long  and  narrow,  their  anterior 
ends  intercalated  between  slender  processes  of  the  pre- 
maxillae,  but  not  reaching  the  external  nostril.  Pre- 
frontals  small,  lachrymals  large.  Orbits  irregularly 
oval,  nearly  as  large  as,  or  larger  than  the  supra- 
temporal vacuities,  and  confluent  with  the  lateral 
temporal  fossae.  Ventral  armour  absent.  Upper 
Cretaceous  to  Kecent. 

Thoracosaurus,  Leidy  (Sphenosaurus,  Ag.). 
Premaxillae  spatulate  in  form,  lachrymals  uii- 
usually  large.  Supratemporal  vacuity  trans- 
versely  oblong,  slightly  larger  than  the  orbits ; 
small  antorbital  vacuity  present.  About  twenty- 
four  curved  teeth  on  either  side  in  each  jaw. 
Upper  Cretaceous ;  New  Jersey,  Holland,  and 
France. 

Holops,  Cope.  Like  the  preceding,  but 
without  antorbital  vacuity,  and  orbits  of  equal 
size  with  supratemporal  vacuities.  Upper  Cre- 
taceous ;  New  Jersey. 

Tomistoma,  Müller  (Bhynchosuchus,  Huxley , 
Gavialosuchus,  Toula  and  Kail),  (Fig.  324). 
Orbits  almost  twice  the  size  of  supratemporal 
vacuities.  Parietals  small,  lachrymals  moderately  developed.  About  twenty 
teeth  on  either  side  in  each  jaw.  Miocene ;  Hungary,  Malta,  and  Sardinia, 
and  Recent  in  Borneo. 


Q^J    0» 


Fig.  324. 

Tomistoma  eggenhurgensis,  Toula  and 
Kail.  Miocene  ;  Eggenburg,  near  Hom, 
Austria.  Dorsal  aspect  of  skull,  i/io» 
Lettering  as  in  Fig.  325. 


ORDER  VII 


CROCODILIA 


221 


Family  2.     Gavialidae. 

Siioiit  prodmed  into  a  long,  narrow  rostrum,  and  passing  ahruptly  into  the  facial 
region.  Nasals  separated  from  premaxillae  hy  a  wide  interval.  Mandibular 
Symphysis  exiended.  Teeth  numerous,  approximately  uniform,  sliglitly  curved, 
acuminate,  and  finely  striated.     Tertiary  and  Recent. 

Gavialis,  Oppel  (Leptorhynchus,  Clift ;  Ehamphostoma,  Wagler),  (Fig.  321). 
Recent  in  India  and  Burmah.  Fossil  in  Pliocene  of  Siwalik  Hills,  India, 
where  it  accompanies  the  gigantic  and  closely  allied  Rhamphosuchus  crassidens. 
Falconer  and  Cautley  (total  length  15  m.),  and  possibly  also  present  in  the 
Eocene  of  Sussex. 

Leptorhamphus,  Oxydontosaurus,  Ameghino.     Tertiary ;  Argentina. 


Family  3.     AUigatoridae. 

Snout  broad  and  short.  Orbits  larger  than  supratemporal  vacuities,  and  conter- 
minous  with  the  lateral  temporal  fossae.  Mandibular  Symphysis  short.  Teeth 
irregulär ;  the  anterior  tooth  of  lower  jaw  always,  and  as  a  rule  also  the  fourth 
tooth,  fitting  into  pits  of  the  upper  jaw.  Suture  between  maxillae  and  premaxillae  on 
the  palate  either  transverse  or  convex  toward  the  front.  Dorsal  armour  consisting  of 
more  than  two  rows  of 
scutes,  either  articulated  n. 

together  or  lying  free  in 
the  integument;  cervical 
scutes  separated  from 
the  dorsal.  Ventral 
armour,  when  present, 
comprising  numerous 
series  of  articidated 
scutes,  each  of  which 
consists  of  two  pieces 
united  by  suture.  Upper 
Cretaceous  to  Recent. 

In  alligators  the 
lower  teeth  bite  en- 
tirely  within  the 
Upper,  and  the  first 
and  fourth  lower  teeth 
are  received  into  pits 
of  the  Upper  jaw  ;  but 
in  crocodiles  the  upper 
and  lower  teeth  mutu- 

,,  .  ,  i__-|^  will  1a  Supefior  and  palätal  aspects  of  skull,  V2-  vi,  Orbit ;/,  Frontal ;  j,  Jugal ;  to, 
ally  interiOCK,  wniie  LacUrymal ;  inx,  Maxilla ;  N,  External  nostril ;  nn,  Nasal ;  pa.  Parietal ;  jmhx, 
the    first    lower    tooth    Riemaxilla  ;  2^rf,  Prefrontal ;  ptf,  Postfrontal ;  S,  Öui)rdtempural  vacuity  ;  sq, 

bites    into   a   Perfora- 
tion or  pit  in  the  cranium,  and   the   fourth  into  a  lateral   notch.     Modern 
alligators  inhabit  the  warmer  regions  of  North  America  and  China,  and  fossil 
remains  occur  in  the  fresh-water.     Cretaceous  and  Tertiary  of  both  Europe 
and  America. 

Diplocynodon,  Pomel  (Figs.  319,  325).     Third  and  fourth   teeth  of  lower 


Fig.  320. 
Diplocynodon  germisi,  Ayniard.     Oligocene  ;  llonzoü,  near  Le  Puy,  France. 


222  REPTILIA 


CL.\Jss  m 


jaw  equally  enlarged,  and  either  both  received  into  pits  of  the  upper  jaw,  or 
the  fourth  passing  into  a  marginal  notch  between  the  maxillae  and  premaxillae. 
Dermal  armour  strongly  developed.  Abundant  in  Upper  Eocene.  (31igocene 
and  Miocene  of  England,  France,  and  Germany. 

Bottosaurus,  Agassiz.  Imperfectly  known,  but  with  alligator-like  dentition. 
Upper  Cretaceous ;  New  Jersey,  Colorado,  and  Montana. 

Alligator,  Cuvier.  Eecent ;  North  America  and  China.  Caiman,  Spix ; 
Jacare,  Gray.     Central  and  South  America. 

Family  4.     Crocodilidae. 

Skull  anteriorly  compressed.  Orbits  larger  than  supratemporal  vacuities,  confluent 
with  the  lateral  temporal  fossae.  Teeih  irregulär,  eighteen  or  nineteen  in  the  upper, 
and  fifteen  in  lower  jaw  on  each  side,  the  two  series  mutually  interlocking.  Anterior 
tooth  in  lower  jaw  received  into  a  pit,  and  fourth  tooth  fitting  into  a  marginal  notch  (m' 
pit).  Suture  between  maxillae  and  premaxillae  on  the  palate  transverse  or  concave  in 
front.  Dorsal  armour  comprising  more  than  two  rows  of  scutes  lying  free  in  the 
integument ;  ventral  armour  wanting. 

Crocodilian  remains  occur  extensively  in  the  fresh-water  Upper  Cretaceous 
and  Tertiaries  of  Europe  and  North  America,  and  in  the  Pliocene  of  India. 
Recent  species  are  distributed  in  tropical  Africa,  East  India,  New  Guinea, 
South  America,  and  Cuba.  The  typical  genus  Crocodilus,  Laurill.  (Figs.  320, 
322,  323),  is  divided  into  a  number  of  sub-genera,  and  is  met  with  in  the  fossil 
State  as  early  as  the  Upper  Cretaceous  of  Europe. 

Range  and  Distribution  of  the  Crocodilia. 

The  earliest  remains  referred  to  this  order  occur  in  the  Trias  of  Germany, 
Scotland,  North  America,  and  India.  Th^ey  are  all  extremely  generalised 
forms,  belonging  to  the  sub-orders  Parasuchia  and  Fseudosuchia,  and  possess  a 
number  of  characters  in  common  with  Dinosaurs,  lihynchocephalians,  and 
Lacertilians.  Many  of  the  Parasuchia,  in  fact,  are  referable  to  Dinosaurs  with 
as  much  propriety  as  to  Crocodilians. 

True  crocodiles,  represented  by  the  Mesoswhia,  appear  rather  suddenly  in 
the  Lias  of  England,  France,  and  Germany,  and  persist  essentially  unmodified 
throughout  'the  Jura.  In  none  of  them  is  the  secondary  palate  developed 
back  of  the  posterior  margin  of  the  palatines,  there  being  no  outgrowths  from 
the  pterygoids,  and  the  vertebrae  are  amphicoelous,  or  at  the  most  amphi- 
platyan.  Their  universal  occurrence  in  marine  deposits,  the  nature  of  their 
fossilised  stomach  contents  and  coprolites,  and  their  general  Organisation, 
prove  them  to  have  been  adapted  for  an  exclusively  aquatic  existence.  The 
earliest  forms  are  all  of  the  longirosträte  variety,  and  it  is  not  until  the  Upper 
Jura  that  short-  and  broad-headed  genera  with  small  supratemporal  vacuities 
are  initiated.  Owen  has  suggested  that  the  appearance  of  the  latter  is  corre- 
lated  with  the  incoming  of  warm-blooded  prey,  and  points  to  the  associaticn 
of  dwarf  crocodiles  in  the  Purbeck  with  small  mammalian  remains. 

Toward  the  close  of  the  Jura  changes  in  external  conditions  seem  to  have 
created  a  new  environment,  for  in  the  Purbeckian  and  Wealden  remains  of 
crocodiles  are  accompanied  for  the  first  time  by  fresh-water  and  terrestrial 
forms,  and  the  indications  suggest  a  fluviatile  habitat.     In  the  Wealden  are 


ORDER  VIII  '  DINOSAURIA  223 

found  a  few  detached  crocodilian  vertebrae  of  the  procoelous  type,  but  it  is 
not  until  the  Upper  Cretaceous  that  typical  Eusuchia  with  extended  secondary 
palate  and  closed  eustachian  passages  become  dominant.  The  Eusuchia, 
like  their  Jurassic  forerunners,  comprise  both  long-snouted  and  broad- 
snouted  genera,  but  whether  the  gavials  were  derived  independently  from  the 
modern  crocodiles  and  alligators,  or  all  aue  traceable  to  a  common  Mesosuchian 
ancestor,  is  still  uncertain.  During  the  Tertiary,  alligators  and  crocodiles 
prevailed  both  in  Europe  and  North  America,  only  becoming  extinct  in  Europe 
during  the  Pliocene.  The  alligators,  which  appear  to  have  surpassed  crocodiles 
in  the  Old  World,  und  to  have  been  inferior  to  them  in  number  in  the  New, 
are  now  restricted  to  the  warmer  regions  of  North  America.  Eemains  of  both 
gavials  and  crocodiles  occur  in  the  Tertiary  of  India,  among  which  are  com- 
prised  the  most  gigaiitic  members  of  the  order  (Bhamphosuchus). 

Order  8.     DINOSAURIA.     Owen.i 

(Pacht/podes,  Owen  ;  Ornithoscelida,  Huxley.) 

Lomj-necked  aud  long-tailed  reptües,  usually  of  coiisiderable  and  sometimes  of 
(jlgantic  size,  with  limbs  adapted  for  haUtual  snpport  of  the  hody.  lavesting  bones 
of  the  temporal  region  of  the  skull  contracting  into  an  upper  and  a  lower  temporal 
arcade,  and  the  large  quadrate  firmly  fixed.  Ä^o  piiteal  foramen.  Teeth  thecodoiif, 
confined  to  margin  of  the  jaw-bones.  Vertebrae  opisthocoelous  or  amphiplatyan,  rarely 
amphicoelous,  sometimes  hollow  or  with  deep  lateral  cavities  ;  sacrum  comprising  from 
two  to  ten  anchylosed  vertebrae.  Ribs  double-headed.  Sternum  incompletely  ossified, 
clavicles  and  p^ecoracoid  absent.  Scapula  very  large,  sometimes  cobssified  with  the 
'perforate  and  anteriorly  rouncled  coracoid.  All  three  pelvic  elements  erdering  the  aceta- 
bulum.  Ilium  large,  antero-posteriorly  extended.  Ischia  usually  slender  and  elongated, 
frequently  united  in  a  median  Symphysis.  Puhis  directed  doimwards  and  forwards, 
sometimes  developing  a  postpubic  prücess  extending  backwards  parallel  with  the  ischium. 
Fore-limbs  shorter  than  the  hinder  pair  ;  progression  very  commonly  bipedal. 

The  Order  Dinosauria  comprises  Mesozoic  reptiles  which  are  extremely 
varied  in  Organisation,  and  exhibit  a  number  of  rhynchocephalian,  crocodilian, 
lacertiliän,  and  even  ornithic  characters,  the  latter  due  chiefly  to  homoplastic 
or  parallel  development.     Among  the  latter,  as  first  noticed  by  Gegenbaur, 

^  Literat  Lire  : 

Baur,  G.,  Der  Tarsus  der  Vögel  und  Dinosaurier  (Morph.  Jalirb.  vol.  VIII.  p.  417),  1883. — 
Bemerkungen  über  das  Becker  der  Vögel  und  Dinosaurier  {ibid.  vol.  X.  p.  613),  1885. — Reniarks  on 
tlie  Reptiles  generally  called  Dinosauria  (Anier.  Nat.  vol.  XXV.  p.  434),  1891.  —  C(>/>^,  E.  D., 
Palaeontological  Bulletins  Nos.  22-28,  in  Pi'oc.  Anier.  Phil.  Soc.  187Ö-77. — J)ollo,  L.,  Notes  sur  les 
Diuosauriens  de  Bernissart  (Bull.  Mus.  d'Hist.  Nat.  Belg.  vols.  T.-III.),  1882-84.  — //«/Xy,  J.  H'., 
Presidential  Addresses  (Quar.  Journ.  Geol.  Soc.  vols.  XXXIX.,  XL.),  1883-84.— //«.(•%,  T.  //.,  On 
the  Aninials  which  are  niost  nearly  intermediate  betvveen  birds  and  Diuosaurs  (Proc.  Koy.  Soc. 
p.  278),  1868.  Also  Ann.  Mag.  Nat.  Hist.  [4],  vol.  I.  (1868),  p.  220.— Further  evidence  on  the 
artiuity  between  the  Dinosaurian  Reptiles  aud  Birds  (Quar.  Journ.  Geol.  Soc.  vol.  XXVII.  p.  12), 
1870. — On  the  Classification  of  the  Dinosauria  {ibid.  p.  32). — Marsh,  0.  C,  Numerous  contributions 
in  Anier.  Journ.  Sei.  [3],  vols.  XVI.-L.  1878-96.— The  Diuosaurs  of  North  America  (16th  Ann.  Rep. 
U.S.  Geol.  Surv.),  1896. — Mehnert,  E.,  Untersuchungen  über  die  Entwickelung  des  os  pubis  der 
Vögel  (Morph.  Jahrb.  vol.  XIII.  p.  239),  1888.— (Mor«,  //.  F.,  Dinosaur  Contributions  Nos.  1-3  in 
Bull.  Amer.  Mus.  Nat.  Hist.  vols.  X.-Xll.,  aud  Memoirs,  vol.  I.  pt.  f),  1898-99. — Reconsideratiou  of 
the  evidence  for  a  common  Dinosaur-avian  stem  in  the  Permian  (Amer.  Nat.  vol.  XXXIV.  p.  777), 
1900.  —  Qiveih  R-^  A  history  of  British  fossil  Reptiles  [Reprint  from  the  publications  of  the 
Palaeontographical  and  other  Societies],  London,  1849-84.— »SVf/^//,  //.  ^'.,  On  the  classilication  of 
the  Dinosauria  (Proc.  Roy.  Soc.  vol.  XLIIL),  1887. 


224  EEPTILIA 


CLA^S!S  III 


the  close  junction  of  the  astragalus  with  the  tibia,  or  tendency  to  form  a 
tibio-tarsus,  is  an  avian  resemblance  common  to  the  majority  of  Dinosaurs. 

While,  on  the  one  hand,  the  cleft  between  Dinosaurs,  crocodiles,  and 
lacertilians .  is  bridged  by  the  Rhynchocephalian  Proterosaurs  {Froganosauriciy 
Baur),  on  the  other  it  may  be  regarded  as  altogether  probable  that  birds 
have  come  down  to  us  from  a  primitive  (perhaps  bipedaU)  Dinosaur- avian 
stem  which  sprang  off  from  a  Palaeohatteria-like  ancestor  in  the  Permian.^  The 
earliest  known  Dinosaurs  (Theropoda)  of  Triassic  age  are  shown  by  their  limb 
structure  and  footprints  to  have  been  mainly  bipedal  in  gait,  and  by  their 
dentition  to  have  been  of  carnivorous  habits ;  of  the  herbivorous  Dinosaurs 
(Sauropoda  and  Predentata)  which  ränge  throughout  the  Jura  and  Cretaceous, 
some  must  have  been  bipedal  and  others  quadrupedal.  The  culmination  of 
Dinosaurs  occurred  during  the  Upper  Jura  and  Cretaceous,  in  the  interval 
between  the  decline  of  Theromorph  reptiles  and  the  dominance  of  the 
Mammalia.  During  their  period  of  ascendency  numerous  hypertrophic 
forms  were  evolved,  which  attained  proportions  far  exceeding  those  of  all 
other  known  terrestrial  creatures.  Over-specialisation  having  run  its  course, 
a  rapid  decline  and  extinction  followed. 

A  bony  exoskeleton  is  developed  to  some  extent  among  certain  of  the 
Theropoda  and  Predentata,  but  in  the  majority  of  Dinosaurs  the  skin  w^as 
either  naked  or  protected  by  horny  scales.  The  dermal  armour,  when 
present,  consists  either  of  isolated  bony  plates  or  spines,  or  of  interlocking 
scutes  which  form  a  continuous  shield  encasing  portions  of  the  trunk  and  tail. 

The  vertehrae  are  usually  either  amphiplatyan  or  opisthocoelous,  more 
rarely  amphicoelous.  There  are  nine  to  fifteen  cervicals,  ten  to  eighteen 
dorsals,  usually  from  two  to  six,  but  sometimes  as  many  as  ten,  fused  sacrals, 
and  thirty  to  fifty  caudal  vertebrae.  The  union  between  the  centra  and 
their  neural  arches  is  commonly  by  suture.  In  the  anterior  cervicals  the 
neural  spines  are  generally  short  or  rudimentary,  and  gradually  increase  in 
size  toward  the  thoracic  region.  The  atlas  and  axis,  so  far  as  known,  exhibit 
a  construction  similar  to  that  in  crocodiles.  All  the  succeeding  cervicals  bear 
double-headed  ribs,  of  which  the  capitulum  is  attached  to  the  parapophysis  of 
the  centrum,  and  the  tuberculum  to  the  transverse  process  of  the  neural  arch. 
In  the  dorsal  region  the  parapophyses  mount  upward  from  the  centra  on  to 
the  sides  of  the  neural  arches.     Single-headed  ribs  do  not  occur. 

Among  the  Theropoda  and  Sauropoda  the  posterior  dorsal  vertebrae  articu- 
late  with  one  another  not  only  by  zygapophyses,  but  by  a  hyposphene- 
hypantrum  arrangement.  The  hyposphene  facette  is  a  vertical  or  wedge-shaped 
protection  occurring  on  the  posterior  end  of  the  neural  arch  below  and 
continuous  with  the  post-zygapophysis.  It  is  received  into  a  corresponding 
groove,  or  hypantrum,  on  the  anterior  face  of  the  next  vertebra  behind.  This 
arrangement  is  similar  in  function  to  the  zygosphen-zygantrum  articulation 
among  Ophidians,  except  that  the  relative  positions  of  pegs  and  sockets  are 
interchanged.  The  sacral  vertebrae,  which  vary  from  two  to  ten  in  number, 
are  fused  together ;  and  the  chevron  bones  of  the  caudals  are  articulated 
intervertebrally. 

The  skull  of  most  Dinosaurs  is  extremely  small  in  proportion  to  the  rest 
of  the  body,  more  so  in  Brontosaurus,  in  fact,  than  in  any  other  reptile,  and 

1  Osborn,  H.  F.,  Reconsideration  of  the  evidence  for  a  common  Diuosaur-avian  stem  in  the 
Permian  (Amer.  Nat.  vol.  XXXIV.  p.  777),  1900. 


ORDER  VIII  DINOSAURIA  225 

the  brain  cavity  is  exceedingly  diminutive.  The  latter,  in  proportion  to  the 
size  of  the  head,  is  smaller  in  Triceratops  than  in  any  known  land  vertebrate. 
Among  the  Theropoda  and  Predentata  the  long  axis  of  the  skull  is  approxi- 
mately  at  right  angles  to  the  neck,  but  in  the  quadrupedal  Saiiropoda  it 
continues  the  line  of  the  vertebral  column.  The  large  orbits  are  laterally 
directed,  and  between  them  and  the  paired  narial  openings  is  frequently  an 
antorbital  vacuity,  as  in  crocodiles,  pterosaurs,  and  birds.  The  temporal 
vacuities  are  completely  enclosed,  and  vary  considerably  in  form  and  size. 
The  large  quadrate  is  prominently  exposed,  and  suturally  united  with  the 
squamosal  and  quadrato-jugal.  The  paired  premaxillae  are  rather  extensively 
developed,  and  either  provided  with  teeth,  or  edentulous  and  beak-like. 

The  inferior  aspect  of  the  skull  is  similar  in  a  general  way  to  that  of 
Rhynchocephalians,  except  that  there  are  no  teeth  on  the  palate.  The 
mandibular  rami  are  united  in  a  cartilaginous  Symphysis,  and  in  the  Pre- 
dentata  a  crescentic,  edentulous,  predentary  bone  is  developed  in  front  of  the 
mandible,  the  sharp  margin  of  which  appears  to  have  been  sheathed  in  a 
horny  beak.  Teeth  are  confined  to  the  margin  of  the  jaws,  and  are  either 
deeply  socketed  or  implanted  in  an  alveolar  groove  open  on  the  inner  side  of 
the  jaws. 

In  the  pedoral  arch  clavicles  appear  to  be  wanting,  and  the  sternum  is 
imperfectly  ossified.  The  scapula  is  very  strongly  developed,  and  usually 
much  elongäted.  The  coracoid  is  flattened,  with  more  or  less  rounded 
anterior  margin,  and  pierced  by  a  foramen  near  its  articular  border.  Some- 
times  the  scapula- coracoid  Clements  are  fused  at  their  proximal  ends,  as 
in  birds. 

The  bones  of  the  appendicular  skeleton  are  sometimes  very  massive,  in 
other  cases  delicate  and  hollow ;  and  the  disparity  between  fore-  and  hind- 
quarters  is  often  very  considerable,  indicating  that  the  presacral  region  was 
ordinarily  lifted  from  the  ground.  The  humerus  in  most  cases  is  inferior  in 
length  to  the  scapula ;  the  radius  and  ulna  are  strongly  developed,  and 
always  separate.  The  carpus  is  often  incompletely  ossified,  and  the  number 
of  metacarpals  is  sometimes  reduced  to  three.  The  digits  are  short,  and 
the  lingual  phalanges  either  hoofed  or  claw-shaped. 

Many  remarkably  avian-like  characters  are  to  be  observed  in  the  pelvic 
arch  and  bones  of  the  bind  limb,  especially  among  the  Predentata.  The  ilium 
is  depressed  and  more  or  less  extended  antero-posteriorly ;  moderately  so  in 
the  triradiate  type  of  pelvis  (Theropoda),  very  much  so  in  the  quadriradiate 
type  (Predentata).  The  long  ischia  extend  backwards  and  downwards,  and 
usually  join  in  a  median  ventral  Symphysis.  The  pre-acetabular  process  of 
the  ilium  (spina  iliaca)  which  serves  for  the  attachment  of  the  pubis,  extends 
further  downward  than  the  post-acetabular  or  ischial  process,  as  in  birds. 
The  acetabulum  itself  is  partly  open,  and  the  sacrum  is  partly  ornithic,  partly 
reptilian. 

In  the  Theropoda  the  pubes  are  long  and  slender,  and  fused  in  an  extended 
ventral  Symphysis.  Among  the  Sauropoda  they  are  shorter,  stouter,  and 
broader  than  the  ischia,  directed  simply  downwards  and  forwards,  and  united 
distally  in  a  median  cartilaginous  Symphysis.  In  the  Predentata  (Fig.  326)  the 
pubis  is  long  and  broad,  but  does  not  join  its  fellow  in  the  median  line  in 
front.  At  its  base,  underneath  the  acetabulum,  it  gives  ofF  a  long  and  slender 
process  known  as  the  post-pubis,  which  is  directed  downward  and  backward 
VOL.  II  Q 


226 


REPTILIA 


CLASS  III 


Fig.  320. 

Pelvis  of  Iguaiiodon,  1/20.     a,  Acetabulum ;    il,  Ilium ;  is. 
Ischium  ;  0,  Obturator  process  ;  p,  Pubis  ;  p',  Postpubic  process. 


parallel  with  the  almost  equally  slender  but  somewhat  longer  ischium.   Althoiigh 
this  post-pubic  process  is  suggestive  at  first  sight  of  the  pubis  of  birds,  it  has 

been  demonstrated  by  the  em- 
bryological  researches  of  Bunge  ^ 
and  Mehnert  ^  that  no  homology 
between  these  structures  exists. 
The  avian  pelvis  is  in  its  earliest 
stages  of  development  triradiate, 
like  that  of  the  primitive  Thero- 
podous  Dinosaurs,  and  the  pubis 
is  directed  forwards  as  in  rep- 
tiles.  Later  the  pubis  becomes 
secondarily  shifted  backwards, 
parallel  with  the  ischium,  and 
the  Processus  üiopedineus  must  be 
regarded  as  a  secondary  struc- 
ture  peculiar  to  birds,  with 
which  the  pubis  of  Dinosaurs 
has,  of  course,  no  homology. 
The  post-pubis  of  the  Predentata 
is  äccordingly  to  be  interpreted  as  a  special  or  adaptive  modification,  probably 
correlated  with  the  function  of  the  tail  in  balancing  the  body  in  locomotion, 
or  while  resting  on  its  bind  quarters. 

ThQ  femur  usually  exceeds  the  humerus  in  length,  and  is  placed  vertical 
to  the  body,  with  its  head  extending  inward  into  the  acetabulum,  as  in  birds. 
Dollo  has  shown  that  the  femur  of  Iguanodon,  with  its  large  fourth  trochanter 
(a  process  which  is  distinct  from  the  "  third  trochanter  "  of  mammals),  is  con- 
structed  more  upon  the  avian  than  reptilian  type,  and  indicates  a  powerful 
caudo-femoral  musculature.  Still  other  ornithic  characters  are  exhibited  by 
the  tibia,  which  possesses  a  large  procnemial  crest,  and  is  often  completely 
embraced  by  the  astragalus  at  its  distal  end.  In  the  Stegosaurs  these  elements 
are  fused,  but  in  most  of  the  carnivorous  Theropoda  the  astragalus  bears  an 
ascending  process,  which  is  opposed  to  the  anterior  face  of  the  lower  end  of 
the  tibia,  exactly  as  in  Pterosaurs  and  young  Ratite  birds.  The  fibula  is 
complete,  the  proximal  tarsals  are  two  in  number  (astragalus  and  calcaneum), 
and  the  distal  two  or  three,  tarsalia  i-lil,  being  usually  fused  into  a  single 
piece.  The  hind  foot  is  either  tridactyl  or  pentadactyl,  but  all  five  metatarsals 
are  commonly  indicated,  even  when  the  number  of  functional  digits  is 
reduced. 

Dinosaur  remains  were  first  discovered  in  the  English  Upper  Jura  and 
Wealden  during  the  early  decades  of  the  last  Century,  and  were  described  by 
Buckland  and  Mantell  in  1825.  Owen,  in  1841,  erected  for  them  the  order 
Dinosauria,  and  much  additional  light  was  shed  on  their  structure  and  relations 
by  Huxley,  Marsh,  and  Cope  prior  to  1875.  Avian  resemblances  were  first 
pointed  out  by  Gegenbaur  in  1864,  who  observed  that  the  tibio-tarsus  of 
Compsognathus  is  decidedly  bird-like.     In  this  form  also  was  detected  the  only 


^  Bunge,  A.,  Zur  Entwicklimgsgescliichte  des  Beckengürtels  der  Amphibien,  Keptilien  und 
Vögel.     Dorpat,  1880. 

^  Mehiurt,  E.,  lieber  die  Entwicklung  des  os  pelvis  der  Vögel  (Morph ol.  Jahrb.  vol.  XIII. 
p.  259),  1888. 


ORDER  VIII  DINOSAURIA  227 

knowii  evidence  of  viviparous  habits  among  Dinosaurs.^  During  the  last 
quarter  of  the  nirieteenth  Century  an  abundance  of  well-preserved  remains  was 
brought  to  light  both  in  the  Old  World  and  in  the  New,  which  lent  a  fresh 
impetus  to  their  study.  The  division  of  the  group  into  three  sub-orders — 
Theropoda,  Sauropoda,  and  Predentata — was  first  proposed  by  0.  C.  Marsh. 


Sub-Order  1.     THEROPODA.     Marsh.^ 

Carnivorous  Diiiosaurs  with  small  cranium,  the  long  axis  of  which  is  approximately 
at  right  angles  to  that  of  the  neck.  Margin  of  the  jaws  provided  with  laterally  com- 
pressed  thecodont  cutting  teeth.  Brain-case  incompletely  ossified ;  antorbital  vacuity 
large.  Mandibular  ramus  without  coronoid  process,  and  usually  pierced  by  a  lateral' 
foramen  in  its  hinder  half.  Vertebral  centra  hollowed,  the  cervicals  flattened  in  front^ 
and  concave  behind  ;  post-cervicals  amphiplatyan  or  slightly  amphicoelous.  Sternum 
unossified  ;  acqtabuliim  pe'rforate.  Fubes  slender,  projecting  simply  dotvnwards,  and 
united  distally,  lilce  the  ischia,  in  a  Symphysis  which  -is  often  much  extended.  Post- 
pubic  process  not  developed.  Limb  bones  hollow,  fore-limbs  considerably  shorter  than  the 
hinder  pair  ;  digits  three  to  five  in  number,  provided  with  prehensile  claws  ;  hind  feet 
(ligitigrade.    Femur  with  inner  trochanter;  astragalus  with  ascemling  anterior  'process. 

The  Theropoda  were  carnivorous  land  Dinosaurs  provided  with  clawed 
digits,  and  varying  excessively  in  size.  Compsognathus,  the  smallest  known 
Dinosaur,  was  no  larger  than  a  cat,  and  Megalosaurus  attained  the  size  of  an 
elephant.  In  outward  appearance  these  animals  must  have  been  very 
grotesque,  owing  to  their  habit  of  stalking  about  on  their  hind  limbs,  or  possibly 
even  leaping  in  kangaroo-fashion  {Hallopus),  with  the  forward  part  of  the  body 
lifted  from  the  ground,  and  balanced  by  the  powerfully  developed  tail.  The 
latter  may  have  served  in  some  cases  also  for  a  swimming  organ,  as  well  as  a 
Support  for  the  animal  when  resting  on  its  hind  quarters  and  pelvic  symphyses. 
The  skeleton  of  many  Theropoda  was  of  very  delicate  construction,  the  vertebrae 
being  often,  and  the  limb  bones  always,  hollow. 

The  skull  is  known  in  comparatively  few  genera.  It  is  similar  in  the 
main  to  that  of  the  Sauropoda,  but  the  brain-case  is  incompletely  ossified,  and 
the  sutures  are  often  indistinct.  The  elongation  of  the  cervical  vertebrae  is 
an  ornithic  character,  as  pointed  out  by  Cope.  All  the  vertebrae  of  the  neck, 
except  the  atlas,  are  concave  behind,  but  usually  flattened  on  the  anterior  face 
of  the  centra ;  they  are  longer  than  the  dorsals,  and  their  neural  spines  are 
only  moderately  developed,  indicating  a  less  powerful  musculature  than  among 
the  Sauropoda.  The  cervical  ribs  are  long  and  nearly  straight,  one  of  their 
articular  heads  being  attached  to  the  centrum,  and  the  other  to  the  neural 
arch.  Each  sacral  rib  is  attached  to  two  vertebrae ;  the  caudals  are  without 
ribs,  but  chevron  bones  are  strongly  developed.  Megalosaurus  and  Compsognathus 
are  remarkable  for  the  possession  of  abdominal  ribs. 

1  Marsh,  0.  C,  Amer.  Journ.  Sei.  [3],  vol.  XXI.  (1881),  p.  340. 

-  Literature  : 

Desloyigchamps,  E,  E.,  Memoir  sur  le  Poikilopleuron  Bucklandii  (M^m.  Soc.  Linn.  Norm.  vol. 
VI.  p.  36),  1838. — Nev)ton,  E.  T.,  On  Ornitliosuchus,  etc.  (Phil.  Trans,  vol.  CLXXXV.  B,  p.  586), 
1894. — Osborn,  H.  F.,  Fore  and  hind  limbs  of  Carnivorous  Dinosaurs  from  the  Jurassic  of  Wyoming 
(Bull.  Amer.  Mus.  Nat.  Hist.  vol.  XII.  p.  161),  1S98.— Phillips,  J.,  Geology  of  Oxford  an<l  the 
Valley  of  the  Thames.  Oxford,  1871. — Plieninger,  T.,  Ueber  Zanclodon,  etc.  (Württ.  naturw. 
Jahresh.  vol.  VIII.  p.  389),  1857.  —  Wagner,  A.,  Ueber  Compsognathus  longipes,  etc.  (Abh.  Bayer. 
Akad.  Wiss.  II.  Classe,  vol.  IX.  p.  94),  1861. 


228 


KEPTILIA 


CLASS  III 


In  the  pectoral  arch  the  scapula  is  longer  and  stouter  than  the  humerus, 
the  coracoid  is  more  or  less  crescentic  or  semicircular,  and  there  is  no  ossified 
sternum.  The  fore-limbs  are  small,  the  carpus  is,  as  a  rule,  incompletely 
ossified,  and  the  clawed  digits  are  of  only  moderate  size.  In  the  pelvic  arch 
the  ilium  is  low  and  antero-posteriorly  extended,  the  post-acetabular  portion 
lower  and  more  elongated  than  the  pre-acetabular,  and  the  acetabulum  itself 
is  perforate.  Both  the  pubes  and  ischia  meet  in  ventral  symphyses,  which  are 
often  much  extended,  and  apparently  served  as  a  support  for  the  body  when 
in  a  crouching  or  sitting  position.  The  structure  of  the  massive  bind  limbs 
indicates  that  progression  was  mainly  bipedal  and  digitigrade.  The  proximal 
tarsals  tend  to  form  a  tibio-tarsus,  and  in  most  genera  the  astragalus  bears  an 
ascending  process,  which  is  immovably  applied  against  the  anterior  face  of  the 
tibia,  as  in  young  ostriches.  Theropoda  first  appear  in  the  Trias,  and  become 
extinct  in  the  Cretaceous. 


Family  1.     Megalosauridae.     Hiixley. 

Vertebrae  solid  and  amphiplatyan,  except  tlit  cervicals,  which  are  opisthocoelous. 

Pubes  long,  projecting  simply  downvjards  and  forwards,  and  united  in  an  extended 

ventral  Symphysis.    Extremities  pentadadyl,  but  the  inner 

and    outer   digits  frequently   rudimentary.       Trias    to 

Upper  Cretaceous. 

Zanclodon,  Plien.  (Plateosaurus,  Teratosaurus, 
Smilodon,  v.  Meyer;  Gresslyosaurus,  Eütim.).  Teeth 
with  serrated  anterior  and  posterior  cutting  edges. 
Vertebral  column  comprising  at  least  sixty  vertebrae, 
three  of  which  are  sacral.  Limb  bones  stout. 
Keuper  ;  Würtemberg.     Z.  laevis,  Plieninger. 

Dimodosaurus,  Pidancet  and  Chof .  Keuper ; 
Poligny,  France.  Cladyodon,  Owen  ;  Thecodoutosaurus, 
Falaeosaurus,  Kiley  and  Stutch.  Trias ;  Bristol, 
England.  Pictchitrema,  Sauvage.  Rhaetic ;  Autun, 
France.  Epicampodon,  Huxley.  Trias  ;  Fast  India. 
PJuscelosaurus,  Huxley.  Trias  ;  South  Africa.  These 
are  imperfectly  kiiown  genera  allied  to  Zanclodon. 

Jnchisaurus,  Marsh  (Fig.  327).  Skull  remark- 
ably  bird-like,  with  very  large  orbits  and  antorbital 
vacuity ;  narial  opening  relatively  small ;  supra- 
temporal vacuity  subrectangular.  Quadrate  inclined 
steeply  forwards.  Teeth  numerous,  nearly  uniform, 
and  closely  set.  Fore-limb  about  two-thirds  as 
large  äs  the  hinder  pair,  with  only  three  clawed 
digits,  the  fourth  and  fifth  rudimentary.  In  the 
pes  the  fifth  digit  is  reduced,  and  the  first  much 
shorter  than  the  rest.  Total  length  slightly  exceed- 
ing  1  m.     Trias  ;  Connecticut. 

Ammosaurus,  Marsh  ;  Bathygnathus,  Leidy  ;  Arcto- 
saurus,  Adams  ;  Clepsysaurus,  Lea.  Represehted  by  fragmentary  remains  from 
the  Trias  of  North  America. 

Ceratosaurus,    Marsh    (Figs.    328,    329).       Skeleton    4-5    m.    long,   skull 


Fig.  327. 

Anchisatirus  major,  Marsh. 
Trias ;  Manchester,  Conn.  1/4. 
Dorsal  aspect  of  right  liind  foot. 
a,  Astragalus ;  c,  Calcaneum ;  /, 
Fibula  ;  t,  Tibia  ;  «2  ■  U,  Distal 
tarsals ;  I — V,  Digits  (after  Marsh). 


ORDER  VIII 


DINOSAUKIA 


229 


relatively  very  large  and  delicate.     Nasal  bones  long,  fused,  and  supporting  a 
large  median  horn-core ;  prefrontals  laterally  swoUen  and  partly  overhanging 


Fig.  32S. 

Ceratosaurus  nasicornis,  Marsh.  Upper  Jura  ;  Colorado.  Skull  from  anterior  (A),  and  lateral  (B),  aspects, 
1/9.  A,  Orbit ;  D,  Antorbital  vacuity  ;  D',  Mandibular  vacuity  ;  N,  Extemal  nostril ;  >',  Supratemponil  vacuity  ; 
(after  Marsh). 


the  Orbits,  which  are  inferior  in  size  to  the  lateral  temporal  vacuities. 
Cervical  vertebrae  strongly  opisthocoelous,  flattened  in  front.  Tail  long, 
compressed  and  deepened   in   its  anterior  portion,  as   indicated  by  the  long 

neural  spines  and  chevron  bones.     Pelvic  elements 
fused  at  the  acetabulum ;   pubic  and  ischial  sym- 
physes   expanded.      Fore-limbs  very   small,   and 
manus  with  four  digits  (i-iv)  each  bearing  a  claw. 
Femur  much  curved  ;    astragalus  not  fused  with 
the  tibia,  but  bearing  a  large 
ascending    process.      Digits 
Nos.  I  and  v  wanting  in  the 
hind  foot ;  metatarsals  fused 
together     (pathologically  ?) 
and  with  the  distal  tarsals. 
Dermal  ossifications  observed 
in  the  neck  region.     Upper 
Jura ;    Colorado.      C.    nasi- 
cornis, Marsh. 


Fig.  329. 
Ceratosaurus  nasicwnis,  Marsh 
Upper  Jura ;  Colorado.     Restora 
tion  of  skeleton,  1/40  (after  Marsh) 


Allosaurus,  Marsh  (Fig.  330).  Skull  unknown.  Vertebrae  and  appen- 
dicular  skeleton  resembling  Ceratosaurus,  except  that  the  pelvic  elements  and 
metatarsals  are  not  fused.     Upper  Jura ;  Colorado. 

Labrosaurus,  Marsh.  Upper  Jura ;  Colorado.  Streptospondylus,  v.  Meyer, 
Upper  Jura ;  Northern  France  and  England. 

Megalosaurus,  Buckland  (Foikilopleuron,  Deslong.),  (Fig.  331).     Teeth  with 


230 


REPTILIA 


serrated  anterior  and   posterior  cutting   edges.     Cervical  vertebrae  slightly 
£  opisthocoelous.       Femur     1    m.    and 

scapula  0*8  m.  long.  Hallux  directed 
inward  as  in  Äpteryx,  and  with  a  com- 
plete  functional  phalanx  and  claw. 
Abdominal  ,  ribs  present.  Lias  to 
Wealden  ;  Europe  and  North 
America. 

Laelaps,  Cope 
(Dryptosaurus, 
Marsh).  Skull 
and  femur  each 
about  0'6  m.  long; 
prefrontal  form- 
ing  a  superciliary 
c  r  e  s  t  ;  o  r  b  i  t 
scarcely  separated 
from  antorbital 
vacuity.  Teeth 
and  other  char- 
acters  similar  to 
Megalosa^irus. 
Upper  Cretaceous; 
Montana. 

Hypsirophus, 
Cope ;  Ornitho- 
mimus,  Marsh ; 
Aublysodon,  Coelo- 
saurus,  Leidy. 
Known    by    frag- 


Allosmirus   agilis 
Restoration  of  anterior  (A). 
1/20  (after  Marsh). 


Fig.  330. 
Marsh.      Upper  Jura ; 


Colorado. 


and  posterior  (B),  limbs, 


Fig.  831. 


Megalosmirnshncklandi, 
V.  Meyer.  Bathonian ; 
Stonesfield,  England. 
Tooth,  i/i- 


mentary  remains  from  the  Upper  Cretaceous  of  North  America. 


Family  2.     Oompsognathidae.     Huxley. 

Vertebrae  and  limb  bones  hollow.  Cervical  vertehi'ae  slightly  opisthocoelous,  post- 
cervicals  amphiplatyan.  Neck  long  and  flexible;  cervical  ribs  styliform.  Pubes 
stout,  ischia  shorter  and  more  slender.  Femur  shorter  than  tibia.  Metatarsals 
long ;  manus  and  pes  with  three  functional  digits,  the  inner  and  outer  ones  rudi- 
rnentary.     Upper  Jura. 

Compsognathus,  Wagner  (Figs.  332,  333).  Represented  by  a  unique 
skeleton  of  a  fully  grown  individual  from  the  Lithographie  Stone  of  Kelheim, 
Bavaria,  and  preserved  in  the  Munich  Museum.  It  is  the  smallest  known 
Dinosaur,  and  interesting  in  that  it  contains  an  embryo  within  the  abdomen, 
first  detected  by  Marsh.  Skull  bird-like,  about  75  mm.  long,  its  long  axis 
set  at  right  angles  to  the  relatijely  long  neck.  The  twenty-two  presacral 
vertebrae  have  a  combined  length  of  20  cm.,  and  the  caudals,  of  which 
only  fifteen  are  preserved,  measure  about  the  same.  Fore-limbs  only  half  as 
long  as  the  hinder  pair.  Proximal  tarsals  tend  to  form  with  the  tibia  a  bird- 
like   tibio-tarsus ;    astragalus    with    long    ascending    process   closely   applied 


ORDER  YIII 


DINOSAURIA 


231 


against   anterior    face   of    tibia ;    distal    tarsals   represented    by   three   small 
flattened  bones.     C.  longipes,  Wagner. 

Ilallojms,  Marsh.  A  small  form  apparently 
related  to  the  preceding.  Fore-limb  relatively 
Short   and   with   four   digits.       Astragalus   without  p     ^s C%:Tii^r-lis 


Comjisogmdhm  longipcs,  W;igner.     Lithographie  Stone  ;  Kelheim, 
Bavaria.     Skeleton,  1/4  (after  A.  Wagner). 

ascending    process ;    calcaneum    produced    into   a 
power  of  leaping.     Upper  Jura  ;  Colorado. 


Fig.  333. 
Compsognathus  longipes, 
Wagner.  Left  hind  foot,  Vi- 
F,  Fibula  ;  mt,  Metatarsals  ;  T, 
Tibia  ;  t2.t5,  Distal  tarsals 
(after  Baur). 

heel,"   suggestive   of  the 


Family  3.     Ooeluridae.     Marsh. 

SkuU  unknown ;  vertehrae  and  all  other  bones  of  the  skeleton  hoUow.  Cervical 
ribs  fused  with  their  centra.  Neural  canoJl  greatly  enlarged.  Metatarsals  very  long 
and  slender.     Upper  Jura  and  AVealden. 

Coelurus,  Marsh  (Aristosuchus,  Seeley).  Known  only  by  portions  of  the  ver- 
tebral  column,  pelvis,  and  limb  bones.  Centra,  neural  arches,  and  all  processes 
of  the  vertebrae  have  hollow  interiors,  and  the  neural  arches  are  suturally 
united  with  their  centra.  In  the  cervical  and  trunk  regions  the  neural  canal  is 
greatly  dilated.     Upper  Jura  ;  Wyoming  and  Maryland.     Wealden  ;  England. 

Thecospondylus,  Seeley  ;  Calamospondylus,  Lydekker.  Wealden ;  England. 
Tichosteus,  Cope.  Upper  Jura  ;  Colorado.  All  these  names  apply  to  detached 
vertebrae.  According  to  Cope,  the  peculiar  vertebrae  described  by  von  Meyer 
from  the  Muschelkalk  of  Bayreuth  under  the  name  of  Tanysti'opheus,  and 
occurring  also  in  the  Trias  of  New  Mexico,  belong  to  this  family. 

Sub-Order  2.     SAUROPODA.     Marsh.     (Cetiosauria.)  ^ 

More  or  less  massive,  herbivorous,  quadrupedal  Dinosaurs.  Skull  relatively  small, 
antorbital  vacuity  large.     Brain-case  completely  ossißed  ;  no  predentary  bone.     Teeth 

^  Literature  : 

Hatcher,  J.  ß.,  Di]ilo(locus,  Marsh  (Mem.  Carnegie  Museum,  vol.  I.),  1901. — Marsh,  0.  C,  The 
Dinosaxirs  of  North  America  (16th  Ann.  Kep.  U.S.  Geol.  Snrv.),  l896.—Osborn,  H.  F.,  Additioual 
characters  of  the  great  herbivorous  Dinosaur,  Camarasaurus  (Bull.  Amer.  Mus.  Nat.  Hist.  vol.  X. 
p.  219),  1898.— A  Skeleton  of  Diplodocus  (Mem.  Amer.  Mus.  Nat.  Hist.  vol.  I.  pt.  V.),  1899.— 
Phillipfi.  J.,  Geology  of  Oxford  and  the  Valley  of  the  Thames.     Oxford,  1871. 


232  REPTILIA  class  iii 


9  spatulate,  with  anterior  and  posterior  cutting  edges.  Cervital  and  anterior  dorsal 
vertebrae  opisthocoelous  and  much  hollowed  on  each  side ;  the  rest  amphiplatyan. 
Neural  canal  much  expanded  in  the  sacrum.  Fubes  moderately  long,  projecting 
simply  downwards,  and  united  distally  hy  cartilage ;  no  post-pubic  process.  Limb 
bones  solid,  feinur  without  prominent  inner  trochanter.  Fore-limbs  only  slightly 
shorter  than  the  hinder  pair.  All  fourfeet  semiplantigrade,  with  five  more  or  less 
reduced  digits ;  distal  row  of  carpals  and  tarsals  apparently  unossified.  Dermal 
armour  absent. 

The  Sauropoda  display  closer  relationships  with  Crocodilians  than  do  the 
other  Orders  of  Dinosaurs,  and  share  a  number  of  features  in  common  with 
the  Parasuchio,.  In  this  order  are  included  some  of  the  most  prodigious  land 
animals  known.  Their  dentition  and  nature  of  the  articulations  prove  clearly 
that  they  were  herbivorous,  and  the  parity  of  their  limbs  demonstrates  the 
gait  to  have  been  in  most  cases  quadrupedal.  Dollo  has  suggested,  how- 
ever,  that  the  latter  habit  was  possibly  secondary,  and  that  all  these  animals 
were  at  one  stage  bipedal  like  the  Iguanodonts,  which  have  a  similar  form 
of  pelvis. 

The  skull  is  incompletely  known  except  in  the  genera  Diplodocus,  Moi'o- 
saurus,  and  Brontosaurus.  Teeth  of  long  cylindrical  or  spatulate  aspect,  and 
with  anterior  and  posterior  cutting  edges,  are  present  in  the  paired  premaxillae 
and  in  at  least  the  anterior  portion  of  the  maxillae.  The  orbits  are  large  and 
laterally  directed,  the  antorbital  vacuities  are  also  extensive,  and  the  external 
nares  elongated.  The  position  of  the  latter  is  between  the  premaxillae, 
maxillae,  and  nasals.     A  predentary  bone  is  not  developed. 

The  cervical  and  anterior  dorsal  vertebrae  are  opisthocoelous,  and  much 
hollowed  along  the  sides.  The  double-headed  cervical  ribs  are  fused  in  part 
at  least  with  their  respective  centra  and  neural  arches,  and  the  neural  spines 
are  reduced  or  paired,  as  in  Diplodocus.  In  the  posterior  dorsal  vertebrae 
there  is  a  hyposphene-hypantrum  arrangement,  as  well  as  pre-  and  post- 
zygapophyses.  The  centra  of  the  dorsal  vertebrae  (Fig.  334),  and  sometimes 
also  of  the  other  regions,  contain  large  interior  cavities,  which  were  probably 
pneumatic  during  life.  These  Chambers,  of  which  there  are  one  or  more  on 
each  side,  are  separated  by  a  median  longitudinal  septum,  not  always  con- 
tinuous,  and  open  outwardly  by  a  foramen  or  elongated  aperture  near  the 
base  of  the  neural  arch.  In  the  presacral  and  anterior  caudal  vertebrae,  the 
neural  arches  and  spines  are  likewise  hollowed.  Each  sacral  vertebra 
Supports  its  own  rib.  In  Diplodocus  the  arches  formed  by  the  diapophysial 
laminae  of  the  sacrum  have  their  origin  in  the  union  of  two  laminae  springing 
from  distinct  vertebrae,  while  each  pair  of  sacral  ribs  originates  from  a  single 
centrum.  The  neural  canal  in  the  sacrum  is  expanded  to  twice  or  three  times 
the  diameter  of  the  brain  cavity.  The  posterior  caudals  have  solid  centra, 
slightly  concave  behind,  and  flat  or  more  rarely  concave  in  front.  Chevron 
bones  are  well  developed. 

In  the  pectoral  arch  the  scapula  is  elongated,  and  much  more  expanded 
distally  than  at ,  its  proximal  end.  The  coracoid  is  small,  more  or  less 
rounded  anteriorly,  and  suggestive  of  the  corresponding  element  in  Rhyncho- 
cephalians.  The  humerus  has  a  distinct  head,  and  is  somewhat  crocodilian- 
like.  The  pelvic  bones  are  never  coössified,  and  the  acetabulum  is  open. 
The  ilium  exhibits  only  a  slight  pre-acetabular  extension,  and  the  slender 
ischium    is   without    an   obturator   process.      The   pubes   are   stout,  directed 


ORDER  VIII 


DINOSAURIA 


233 


downwards  and  forwards,  and  meet  in  a  cartilaginous  Symphysis.  The  femur 
is  considerably  longer  than  the  crus,  and  its  large  head  is  directed  inward 
from  the  shaft  to  enter  the  acetabulum.  The  astragalus  is  without  an 
ascending  process.  All  the  phalanges  are  short,  and  the  lingual  ones  are 
compressed,  and  were  sheathed  with  hörn,  or  hoof-like. 

Eemains  of  Sauropoda  occur  principally  in  the  Middle  and  Upper  Jura  of 
England  and  Northern  France,  and  in  the  equivalent  formations  of  the  western 
United  States,  especially  Wyoming  and  Colorado.  They  are  also  known  from 
the  Wealden  and  Lower  Cretaceous  of  England,  and  from  the  Upper  Mesozoic 
of  Madagascar,  India,  and  Patagonia. 

Family  1.     Camarasauridae.     Cope.     (Ätlantosauridae.) 

Teeth  more  or  less  compressed,  and  with  anterior  and  posterior  cutting  edges. 
Chevron  bones  articulated  with  the  solid  caudal  vertebrae.     Jura  and  Wealden. 

Cefiosaurus,  Owen  {Cardiodon,  Owen).  A  skeleton  lacking  the  skull  and 
cervical    vertebrae    (C.  oxoniensis,  Phillips,   from    the  Bathonian    of    Oxford, 


Fig.  334. 

Ornithopsis  hulkei,  Seeley.  Wealden ;  Isle  of  Wight.  A,  Auterior  aspect.  B,  lateral  aspect.  C,  Cross- 
section  of  dorsal  vertebra,  i/g.  b.  Anterior  face  of  centrum  ;  c,  Posterior  cup  ;  d,  Transverse  process  ;  /,  Lateral 
air-eavity  ;  hs2>,  Hyposphene  ;  n,  Neural  canal ;  o,  Median  septum  ;  p,  Capitular  facette  for  rib ;  s,  Neural  spine; 
z,  z',  Pre-  and  post-zygapophyses  ;  za,  Hypantrum  (after  Hulke). 

England),  indicates  a  total  length  of  at  least  12  m.,  and  a  height  of  about 
3  m.  Humerus  and  femur  are  of  about  equal  length,  the  latter  TT  m.  long. 
Ischia  smaller  than  the  pubes,  and  distally  contracted.  Middle  Jura; 
England. 

Camarasaurus,  Cope  (Atlantosaurus),  Marsh.     Fore-limbs  longer  than  the 


234 


EEPTILIA 


CLASS  III 


fa    ^ 


hinder  pair,  humerus  of  equal 
length  with  the  femur,  thorax 
proportionally    large.     Scapula 


P"IG.  33(3. 

Brontosaurus  excelsus,  Marsh.    Upper  Jura 
Wyoiniiiff.      A,   Posterior    aspect    of    sixtli 
cervical    vertebra.      B,    Lateral    asjjcct    of 
dorsal  vertebra,  1/12.     Lettering  as  in  Fig. 
334  (after  Marsh). 


expanded 


expanded  at  proximal  end, 
coracoid  elongate  and  straight 
at  articular  border.     Centra  of 


ORDER  VIII 


DINOSAURIA 


235 


dorsal  vertebrae  elongate  and  but  slightly  hollowed  laterally.  Sacrum  com- 
posed  of  four  aiichylosed  vertebrae  having  slight  cavities  in  the  centra. 
Ischia  distally  expanded  and  meeting  in  a  ventral  Symphysis.  Anterior 
caudal  vertebrae  relatively  small,  having  short,  blunt  transverse  processes 
and  no  lateral  cavities,     IJpper  Jura  ;  Colorado. 

Brontosaurus,  Marsh  (1  Ämphicoeleas,  Cope),  (Figs.  335,  336).  Total  length 
upwards  of  18  m.  Skull  remarkably  small,  and  brain  cavity  exceedingly 
diminutive.  Neck  long 
and  flexible,  trunk  short, 
and  tail  elongated. 
About  thirteen  cervical 
vertebrae,  with  -very 
small  neural  canal,  and 
no  neural  spines.  Cer- 
vical ribs  hatchet-shaped, 
the  anterior  ones  fused 
with  their  centra,  the 
hinder  ones  articulated. 
All  the  centra  deeply 
hollowed,    the    inner 


Fig.  337. 

Morosaurus  grandis,  Marsh. 

Upper    Jura ;    Wyoming.      A,   B, 

liateral    and    anterior   aspects    of 

tooth,  I/o. 


Fig.  338. 
Morosaurus  grandis,  Marsh.  Upper  Jura ;  Wyoming.  .1,  B,  Lateral 
and  posterior  aspects  of  fourth  cervical  vertebra,  Vs-  Lettering  as  in 
Fig.  334.  C,  Pelvis  viewed  froni  in  front,  Vir-  «-;>.  The  four  sacral 
vertebrae ;  h,  c,  e,  Transverse  processes ;  il,  llium ;  is,  Ischiuni ;  nc, 
Neural  canal ;  pb,  Pubis  (after  Marsh). 


cavities  of  the  dorsals  divided  by  a  narrow  median  septum.  The  five  sacral 
vertebrae  are  fused,  as  are  also  the  neural  spines  of  the  three  median  sacrals. 
A  pair  of  supposed  sternal  bones  between  the  perforated  coracoids.  Ischia 
less  robust  than  the  pubes,  somewhat  expanded  distally,  and  meeting  in  a 
ventral  Symphysis.     Upper  Jura  ;  Wyoming  and  Colorado. 

.Morosaurus^  Marsh  (Figs.  337,  338).  Cervical  ribs  not  fused  with  their 
supporting  processes.  Neck  extremely  long  and  flexible,  back  short,  with  but 
ten  dorsal  vertebrae.  Chevron  bones  articulated  by  two  facettes,  with  their 
centra.     Four  sacral  vertebrae.     Shaft  of  pubes  rotated  distally  through  a 


236 


EEPTILIA 


CLASS  III 


quadrant  of  arc,  so  that  the  pubic  Symphysis 
is  formed  by  the  lateral  faces  instead  of 
extremities  of  the  bones.  Upper  Jura ; 
Wyoming  and  Colorado. 

Apatosaurus,  Marsh.  Upper  Jura  -, 
Colorado.  Pleurocoelus,  Marsh.  Lower  Cre- 
taceous ;  Maryland. 

Ornithopsis,  Seeley  (Pelorosaurus,  Mantell ; 
Uucamerotus,  Hulke ;  Chondrosteosaurus,  Both- 
riospondylus,    Owen),    (Fig.    334).       Cervical 


Fig.  339. 

Diplodocus  longus,  Marsh.    Upper  Jura  ;  Caöoii  City,  Colorado. 
Skull,  Vs  (after  Marsh). 

vertebrae  elongated,  dorsals  with  expanded 
neural  canal.  Fragmentary  remains  of  large 
size  frequent  in  the  Upper  Jura  and  Wealden 
of  England.     0.  hulkei,  Seeley. 

Titanosaurus,     Argyrosaurus,      Lydekker. 
Supposed  Cretaceous  of  Patagonia. 


f/^' 


'^ 


Family  2.     Diplodocidae.     Marsh. 

Teeth  slender  and  cylindrkal,  confined  to 
front  margin  of  the  jaws.  External  narial 
opening  small,  unpaired,  placed  at  apex  of  the 
skull.  Caudal  vertebrae  elongated,  mntrally 
excavated ;  chevron  bones  double  posteriorly,  each 
having  both  anterior  and  posterior  branches. 
Upper  Jura. 

Diplodocus,     Marsh    (Fig.    339).       Total 


ORDER  VIII  DINOSAURIA  237 

length  upward  of  20  m. ;  skull  only  0'6  m.  long,  elevated  and  laterally  com- 
pressed.  In  front  of  the  triangulär  antorbital  vacuity  is  a  small  maxillary 
vacuity  ;  supratemporal  fossa  very  small ;  quadrate  much  inclined  forwards. 
Neck  extremely  long  and  flexible,  and  back  extremely  short.  At  least  fifteen 
cervicals,  eleven  dorsals,  four  sacrals,  and  thirty-seven  or  more  caudals  present. 
Stenialbones  as  in  ßrontosaurus.     Upper  Jura;  Wyoming  and  Colorado. 

Sub-Order  3.     PREDENTATA.     Marsh.     (Orthopoda,  Cope.)  ^ 

Large  herbivorous  Dinosaurs  with  completely  ossified  brain  case,  little  or  no 
antorbital  vacuity  in  the  skull,  and  toothless  predentary  bone  in  front  of  the  mandible. 
'  Premaxillae  edentulous  at  least  in  front  (rarehj  with  small  lateral  teeth) ;  maxillae 
and  dentary  with  stout  grinding  teeth,  arranged  in  one  or  more  functional  series. 
Teeth  usually  compressed  or  spatulate,  with  serrated  anterior  and  posterior  cutting 
edges,  but  becoming  worn  down  to  flattened  stumps  with  age.  External  nares  large, 
placed  at  extremity  of  the  skull.  Vertebral  centra  solid,  opisthocoelous,  amphiplatyan, 
or  sometimes  even  amphicoelous.  Cervical  ribs  loosely  articulated  with  their  centra. 
Pubes  slender  and  distally  free.  Fost-pubis  slender,  of  variable  length,  and  directed 
downwards  and  backwards  parallel  with  the  ischium  ;  the  latter  with  obtiirator  process. 
Limb  bones  solid  or  hollow ;  anterior  extremities  shorter  than  the  hinder  pair. 
Ästragalus  without  ascending  process  ;  hind  feet  digitigrade  or  plantigrade. 
Dermal  armour  sometimes  strongly  developed  (Stegosauria),  in  other  cases  absent 
(Iguanodontia). 

This  sub-order  comprises  more  or  less  massive  herbivorous  Dinosaurs,  some 
of  vrhich  must  have  been  bipedal  in  galt,  and  others  quadrupedal.  They  are 
distinguished  from  the  preceding  groups  chiefly  by  characters  of  the  pelvis, 
presence  of  a  predentary  bone,  and  edentulous  premaxillae.  The  unarmoured 
Predentata  are  represented  by  the  bipedal  Ornithopodidae  (  =  Iguanodontia),  and 
the  armoured  division  by  the  quadrupedal  Sfegosauridae  and  Ceratopsidae. 

Family  1,     Iguanodontidae.=^ 

Long  axis  of  skull  set  at  right  angles  to  the  neck.  Antorbital  vacuity  small, 
mandibular  coronoid  process  strongly  developed.  Teeth,  when  unworn,  of  petaloid 
aspect,  socketed  in  a  Single  functional  row.  Cervical  and  anterior  dorsal  vertebrae 
upisthocoelous.  Pelvis  of  the  quadriradiate  type  ;  post-pubic  process  long  and  slender  ; 
fore-limbs  only  about  half  as  long  as  the  hinder  pair  ;  pes  tridactyl,  clawed  or  hoofed  ; 
galt  bipedal  and  digitigrade.    Dermal  armour  absent.    Upper  Jura  and  Cretaceous. 

The  pelvis,  as  has  already  been  pointed  out  (cf.  Fig.  326),  is  more  bird-like 
than  that  of  any  other   reptilian   group.     The   ilium   generally  has   its   pre- 

^  Literature : 

Marsh,  0.  C,  The  Dinosaurs  of  North  America  (16th  Ann.  Rep.  U.S.  Geol.  Surv.),  1896. 

'^  Literature  : 

Cope,  E.  D.,  On  the  characters  of  the  skull  in  the  Hadrosauridae  (Proc.  Acad.  Nat.  Sei.  Philad. 
p,  98),  1883. — Düllo,  L.,  Notes  sur  les  Dinosauriens  de  Bernissart  (Bull.  Mus.  d'Hist.  Nat.  Belg. 
vols.  I.,  II.),  1882-84. — Hulke,  J.  W.,  On  Hypsilophodon  Foxii  (Quar.  Journ.  Geol.  Soc.  vol. 
XXIX.  p.  522),  1873.— Also  ibid.  vol.  XXX.  (1874),  p.  18,  and  Phil.  Trans,  vol.  CLXXIII.  (1882), 
p.  lOSo.—Hiixleij,  T.  H.,  On  Hypsilophodon  (Quar.  Journ.  Geol.  Soc.  vol.  XXVI.  p.  3),  1870.— 
Leidy,  J.,  Cretaceous  Reptiles  of  the  United  States  (Smithson.  Mise.  Contrib.),  1864. — Mantell, 
G.  A.,  Oljservations  on  Iguanodon,  Hylaeosaurus,  etc.  (Phil.  Trans.),  1825,  1841,  1848,  1849. — 
Afarsh,  O.  O.,  On  Hypsilophodon,  etc.  (Araer.  Journ.  Sic.  [3],  vol.  L.),  1895. — Nopcsa,  Jr.,  F.  B., 
Dinosaurienre.ste  aus  Siebenbürgen  (Denkschr.  Akad.  Wissensch.  Wien,  vol.  LXVIIL),  1899. 


238 


REPTILIA 


CLASS  III 


acetabular  portion  much  extended,  and  the  ischium  has  an  obturator  process. 
Supposed  sternal  ossifications  sometimes  occur. 

Camptosaurus,  Marsh  (Camptonotus,  Marsh).  Attaining  a  total  length  of 
about  10  m.  Cervical  ribs  short ;  dorsal  vertebrae  amphiplatyan  ;  sacrals 
not  anchylosed.  Pubis  robust,  post-pubis  of  equal  length  with  the  long  and 
slender  ischium.  Pendent  inner  fourth  trochanter  of  femur  very  marked. 
Proximal  tarsals  separated.  Upper  Jura ;  Wyoming  and  Colorado.  Kim- 
meridgian  and  Wealden  ;  England. 

Laosaurus,  Dnjosauras,  Nanosaurus,  Marsh.  Upper  Jura ;  Wyoming  and 
Colorado. 

Hi/psilöpJiodon,  Huxley.  Premaxillae  each  with  five  small  deeply-socketed 
lateral  teeth,  edentulous  and  beak-like  in  front;  nasals  elongated.  Yertebrae 
amphiplatyan.      Sternum  partly  ossified.     Post-pubis  of  equal  length  with  the 


Pmx-fri 


Pd. 


Fio.  340. 

Iguanodon  bernissartensis,  Boul.  Wealden;  Bernissart,  Belgiuni.  Skull,  i/g.  A,  Orbit;  art,  Articular;  '/, 
Dentary  ;  fr,  Frontal ;  jv,  Jugal ;  la,  Lachrymal ;  mx,  Maxilla  ;  N,  External  nostril ;  na,  Nasal ;  pa,  Parietal ; 
pd,  Predentary ;  pmx,  Premaxilla  ;  ptf.  Postfrontal;  qu,  Quadrate;  quj,  Quadrate -jugal ;  .S',  Supratemporal 
vacuity  ;  sq,  Squainosal ;  x,  y,  Supraorbitals  (after  Dollo). 

ischium ;  proximal  tarsals  separated ;  manus  and  pes  each  with  four  clawed 
digits.  Known  by  several  complete  skeletons  TS  m.  long  from  the  Wealden 
of  the  Isle  of  Wight. 

Iguanodon,  Mantell  (Figs.  340-342).  Skull  laterally  compressed,  with 
large,  nearly  terminal  nostrils,  and  small  antorbital  vacuity.  Orbits  deeper 
than  wide,  smaller  than  the  irregularly  triangulär  or  elongated  lateral  temporal 
vacuity.  Supratemporal  vacuities  of  moderate  size,  separated  by  the  narrow 
parietals,  which  meet  in  a  sharp  median  crest.  Two  small  supraorbital  bones 
above  the  eye,  but  no  sclerotic  ring.  Frontals  flattened  and  apparently  fused ; 
nasals  elongated.  Mandibular  Suspensorium  nearly  vertical ;  articular  portion 
of  the  quadrate  at  the  base  of  an  unusually  deep  pedicle.  Jugal  crescentic, 
bounding  the  orbit  inferiorly ;  quadrato- jugal  rather  large ;  lachrymal  small. 
Premaxillae  toothless,  but  with  sharpened  margin.  Maxillae  and  dentary 
with  numerous  closely-set  grinding  teeth  arranged  in  a  single  row ;  the  teeth 
when  unworn  are  spatulate,  loosely  socketed,  and  with  serrated  margins ; 
successional  teeth  well  formed  below  those  of  the  functional  row.    Mandibular 


ORDER  VIH 


DINOSAURIA 


239 


ramus  composed  of  six  pieces,  and  with  slender  coronoid  process.  There  are 
teil  cervical,  eighteen  dorso-lumbar,  four  to  six  sacral,  and  forty  to  fifty  caudal 
vertebrae.     All  the  presacral  vertebrae  except  the  atlas  and  a  few  lumbars 

bear  ribs,  as   do  also  the   thirteen 

anterior  caudals.     Ossified   tendons 

frequently  observed  along  the  neural 

'  **  ^K5^  spines  of  the  back  and  tail.    Scapula 

very  long  and  slender ;  coracoid 
small  and  rounded,  notched  or  per- 
forate  at  its  articular  border ; 
supposed     pair    of     sternal     bones 


>.^-'' 


Fig.  341 


Ljuanodoii  mantelli,  Owen.  Wealden  ;  Isle  of  Wight. 
Inner  (A),  and  posterior  (B)  aspects  of  mandibular  tooth 
(after  Mantell). 


triangulär.  Manus 
pentadactyl,  the 
pollex  reduced  to  a 
Single  spur-like 
phalanx ;  the  others 
having  a  formula  of 
3,  3,  3,  4.  Iliuni 
greatly  extended  on 
either  side  of  the 
acetabulum.  Post- 
pubis  process  slender 
and  rod-like,  shorter 
than     the     ischium. 


Fio.  34S 


Jguunodon  bernissartensis,  Boul.     Wealden  ;  Bernissart,  Belgiiun.     Complete 
skeleton,  i/ßo-     co,  Coracoid  ;  is,  Ischium  ;  p,  Pubis ;  pj>,  Postpubic  process  ;  sc, 
remur         SCarcely    Scapula  ;  I—  V,  Digits  (after  Dollo). 

ionger  than  the  crus, 

and  with  prominent  pendent  inner  trochanter.  This,  according  to  Dollo,  is 
distinct  from  the  third  trochanter  of  mammals,  and  indicates  a  powerful  caudo- 
femoral  musculature,  as  in  birds.  Metatarsal  No.  l  rudimentary,  No.  V  wanting ; 
the  three  ungual  phalanges  broad  and  claw-shaped  ;  formula  of  pes,  0,  3,  4,  5,  0. 
Iguanodon  is  known  by  numerous  complete  skeletons  from  the  Wealden  of 
Bernissart,  near  Mons,  Belgium,  as  many  as  twenty -three  being  exhibited  in  the 
Brüssels  Museum.  Fragmentary  remains  occur  also  in  the  English  Wealden. 
Lower  Greensand,  Purbeckian,  and  perhaps  also  in  the  Kimmeridge  Clay.  The 
typical  species,  /.  mantelli,  Owen,  from  the  Wealden  of  England,  attains  a  total 
length  of  6  m.,  and  /.  bernissartensis,  Boulenger  (  =  /.  seelej/i,  Hulke),  is  between 
8  and  10  m.  long.  As  proved  by  its  three-toed  footmarks,  the  animal  walked 
on  its  bind  feet  in  a  kangaroo-like  attitude,  thus  leaving  the  hands  free  for 
prehension. 


240 


EEPTILIA 


CLASR  III 


Trachodon,  Leidy  (Radrosaurus,  Thespesius,  Leidy ;   Diclonius,  Cope),  (Figs. 
343-345).     Skull  elongated,  depressed,  with  broad,  beak-like  siiout,  very  large 


Pnix: 


art 


aug- 


Prd 


Fig.  343. 


Trachodon  mirahilis,  Leidy.  Uppermost  Cretaceous  (Laramie  Formation);  Dakota.  Superior  and  lateral 
aspects  of  skull,  1/12.  A,  Orbit;  ang,  Angular;  art,  Articular ;  fr,  Frontal;  jit,  Jugal  ;  la,  Laclirymal ;  mx, 
Maxiila  ;  N,  Antorbital  vacuity ;  na,  Nasal ;  pa,  Parietal ;  pmx,  Premaxilla  ;  prd,  Predentary  ;  prf,  Prefrontal ; 
ptf.  Postfrontal;  qu,  Quadrate;  quj,  Quadrato-jugal ;  S,  Lateral  temporal  vacuity;  S',  Supratemporal  vacuity; 
so,  Supraoccipital ;  sq,  Squamosal  (after  Cope). 


nostrils,  subrectangular  orbits,  and  long  and  narrow  temporal  vacuities.   Parietal 

ABC 


Fig.  344. 

Trachodon  foidki,  Leidy.  Upper  Cretaceous ; 
New  Jersey.  Inner  (.4),  outer  (JS),  and  (C),  lateral 
aspects  of  mandibular  tootli,  somewhat  worn,  1/1 
(after  Leidy). 


KKi.  34ü. 

Trachodon  breviceps,  Marsh  sp.  LTpper  Cretaceous  ; 
Montana.  A,  Inner,  and  B,  Superior  aspect  of 
functional  and  successionäl  teeth  of  dentary,  1/4 
(after  Marsh). 


very  small ;  premaxillae  edentulous.      Teeth  closely  arranged  in  an  alveolar 
groove  opening  inwardly,  the   successionäl   teeth   forming  several   tectiform 


ORDER  VIII  DINOSAUEIA  241 

series.  Dorsal  vertebrae  opisthocoelous ;  caudals  amphiplatyari.  Other 
characters  as  in  Iguanodon.  Upper  Cretaceous ;  New  Jersey,  Dakota,  and 
Montana. 

Claosaurus,  Marsh.  Skull  very  similar  to  the  preceding,  and  the  genus 
possibly  not  distinct  from  Trachodon.  Nostrils  large,  and  no  supra-orbital 
bones  observed.  There  are  thirty  presacral  vertebrae,  nine  fused  sacrals,  and 
about  sixty  caudals.  All  the  presacrals  are  opisthocoelous  and  costiferous ; 
anterior  caudals  also  opisthocoelous,  and  with  very  long  chevron  bones.  Fore- 
limbs  unusually  short  and  small  in  proportion  to  the  hinder  pair.  In  the 
manus  digit  l  is  rudimentary,  and  No.  V  is  wanting ;  functional  digits 
hoofed,  each  with  three  phalanges.  Functional  digits  of  bind  foot  very 
massive,  with  broad  hoofs ;  their  formula  0,  3,  4,  5,  0.  C.  amiedans,  Marsh, 
attains  a  length  of  9  m.  A  complete  mounted  skeleton  in  Yale  Museum. 
Upper  Cretaceous ;  Colorado,  Wyoming,  and  Montana. 

Limnosaurus,  Nopsca.     Cretaceous  ;  Austria. 

Family  2.     Stegosauridae.     Marsli.     {Bcelidosauridae,  Huxley.)  i 

Skull  small,  without  antorUtal  vacuity  ;  nostrils  large  and  placed  far  forwards  ; 
premaxillae  edentulous.  Vertebrae  amphicoelous  or  amphiplatyan,  and  solid  ihrough- 
ouf,  like  the  limb  bones.  Post-pubic  process  robust ;  fore-limbs  much  smaller  than  the 
hinder  pair.  Feet  plantigrade,  tri-  or  penta-dadyle,  with  short,  hoof-like,  ungual 
phalanges,  Exoskeleton  strongly  developed,  consisting  of  a  series  of  large  dermal 
plates  and  spines.     Lias  to  Upper  Cretaceous. 

This  family  comprises  moderate  or  large -sized  Predentata,  with  well- 
developed  exoskeleton,  solid  limb  bones,  and  solid  amphicoelous  or  amphi- 
platyan vertebrae.  The  dermal  armour  usually  consists  of  large  bony 
plates  or  spines,  but  in  a  few  genera  the  back  is  encased  in  a  continuous 
shield  of  fused  plates  (Polacanthus).  The  neural  canal  of  the  sacrum  is 
sometimes  enormously  expanded.  In  the  pelvis  the  post-pubic  process  is 
greatly  extended,  as  in  the  Ornithopodidae,  and  there  is  likewise  a  marked 
disparity  between  the  fore-  and  hind-limbs.  The  galt  was  probably  in  most 
cases  quadrupedal,  although  a  study  of  femoral  characteristics  has  led  Dollo 
to  suggest  that  they  may  have  been  at  least  at  one  stage  bipedal. 

Sfegosaurus,  Marsh  (Figs.  346-348),  Skull  narrow  and  depressed,  relatively 
very  small,  and  brain  cavity  in  proportion  to  size  of  the  body  more  diminutive 
than  in  any  other  land  vertebrate.  Orbits  small ;  laterally  directed ;  supra- 
temporal vacuities  small  and  rounded ;  nasals  nearly  half  as  long  as  the  skull. 
Mandibular  ramus  deep,  pierced  by  a  lateral  foramen.  Teeth  very  numerous, 
bluntly  pointed,  more  or  less  spatulate  in  form,  loosely  socketed  in  a  single 
functional  series.  Vertebrae  slightly  amphicoelous  or  with  flat  ends,  the 
cervicals  with  short  ribs  and  dorsals  with  much  elevated  neural  arches,  on 
which  the  stout  dorsal  ribs  are  borne.  Sacrum  of  four  fused  vertebrae,  some- 
times with  one  or  more  lumbars  added  on  in  front ;  their  neural  canal  enlarged 

^  Literature  : 

Bunzel,  E.,  Reptilien  der  Gosauformation  (Abhandl.  Geol.  Reichs.  Austalt,  vol.  V.  pt.  1),  1871. 
—Davies,  W.,  On  the  exhumation  of  Omosaurns  (Geol.  Mag.  [2],  vol.  III.  p.  193),  1876.— Hidke, 
J.  W.,  On  Polacanthus  (Phil.  Trans,  vol.  CLXXVIII.  B,  p.  169),  1887.— Marsh,  0.  C,  On  Scleido- 
saurus,  etc.  (Amer.  Journ.  Sei.  [3],  vol.  L.),  1895.— Seelei/,  H.  G.,  The  Reptile  Fauna  of  the  Gosau 
Formation  (Quar.  Journ.  Geol.  Soc.  vol.  XXVI.  p.  620),  1881.— On  Polacanthus,  etc.  {ibid.  vol. 
XLVIII.  p.  81),  1892. 

VOL.  II  R 


242  KEPTILIA  cla.ss  iii 

to  ten  times  the  capacity  of  brain  cavity  (Fig.  347).      Anterior  caudal  vertebrae 


Fig.  346. 

Stiujosaurus  stenops,  Marsh.     Upper  Jura  ;  Colorado.     Superior  and  lateral  aspects  of  skull, 
i/e  (after  Marsh). 

the  largest  in^the  column,  and  with  strong  chevron   bones.     Fore-limb  short 
A  and  stout,  uina  with  large  olecranon  pro- 

cess.  Manus  short,  apparently  penta- 
dactyle.  Femur  large  and  straight, 
without  inner  trochanter ;  tibia  and 
fibula  much  shorter.  Astragalus  and 
calcaneum  fused  Avith  opposing  bones  of 
the  crus ;  pes  tridactyle,  digit  No.  l 
rudimentary,  and  No.  v  wanting. 
Dermal  armour  consisting  of  two  rows 
of  flattened  bony  plates  extending  from 
the  back  of  the  head  well  down  the  tail, 
the  largest  plates  situated  immediately 
over  the  pelvis.  Four  spines  on  the 
tail,  and  throat  protected  by  a  shield  of 
irregulär  ossicles.  Known  by  complete 
skeletons  from  the  Upper  Jura  of 
Wyoming  and  Colorado.  S.  nngulatus, 
Marsh,  over  9  m.  long. 

Diracodon^     Marsh.        Is     probably 
founded  on  tjie  young  of  this  species. 

ScelidosauruSy  Owen.  Skull  only 
about  0*25  m.  long.  Teeth  with  tri- 
angulär or  spatulate  crowns,  coarsely 
serrated  on  the  margins.  All  the  centra 
amphicoelous,  some  with  an  internal 
cavity,  and  the  neural  canal  not  expanded.  There  are  six  or  seven  cervicals, 
sixteen  dorsals,  one  lumbar,  four  sacrals,  and  about  forty   caudals.     Femur, 


Fig.  347. 
unciulatus,    Marsh. 


Upper    Jura  : 


Stegosaunis 
Colorado.  A,  Gutta-percha  cast  of  neural  canal  in 
sacrum,  dorsal  aspect,  1/4-  J^>  Same  of  brain  cavity, 
1/4.  a,  Anterior  end ;  c,  Cerebral  hemisphei'es ;  cb, 
Cerebellum ;  /,  Vacuities  between  transversa  pro- 
cesses  of  sacrum ;  m,  MeduUa  oblongata ;  ol,  Olfac- 
tory  lobe  ;  op,  Optic  lobe  ;  p,  Posterior  end. 


ORDER  VIII 


DINOSAURIA 


243 


tibia,  and  fibula  hollow,  the  crus  somewhat  shorter  thaii  the  femur  and  not 
fused  with  proximal  tarsals.  Hind  foot  functionally  tridactyle.  the  hallux 
reduced,  and  digit  No.  v  wanting ;  phalangeal  formula  2,  3,  4,  5,  0.  Dermal 
armour  of  longitudinal  series  of  small  tubercles  and  triangulär  or  conical 
scutes  covering  the  back  and  tail.  S.  harrisoni,  Owen,  attains  a  length  of  4  m. 
Lower  Lias  ;  England. 

Echinodon,  Owen.     Purbeckian ;   England.     Hylaeosaurus,  Mantell ;    Fedi- 
saurus,  Hulke  ;  Stenopelix,  v.  Meyer.      Wealden.     All  imperfectly  known. 


7]i  /'' 


Fig.  348. 
Stegosaurus  ungulatus,  Marsh.     Upper  Jura  ;  Colorado.     Restoration  of  skeleton,  Viio  (aftpr  Marsh). 

Polacanthus,  Owen.  Lumbar-sacral  region  completely  encased  in  a  con- 
tinuous  shield  of  fused  plates,  which  press  the  ilium  downwards.  Wealden ; 
Isle  of  Wight. 

Friconodon,  Marsh.  Founded  on  detached  teeth  from  the  supposed  Upper 
Jura  of  Maryland. 

From  the  Upper  Cretaceous  of  Austria  and  North  America  a  number  of 
fragmentary  remains  of  armoured  OrnitJiopoda  have  been  described  under  the 
names  of  Struthiosaiirus  and  Danubiosaurus,  Bunzel ;  and  Crataeomus,  OligosauruSy 
and  Hoplosawus,  Seeley,  etc.  Like  the  members  of  the  following  family,  they 
are  supposed  to  represent  a  highly  specialised  group  of  Stegosaurs. 


Family  3.     Ceratopsidae.     Mareli. 

Skull  of  enormous  size,  wedge-shaped  in  form,  very  narrow  in  the  facial  portion, 
with  two  very  large  pointed  horns  on  the  frontals,  a  median  nasal  hörn  ariteriorly,  and 
a  row  of  sharp  projedions  around  the  margin  of  the  posterior  hood,  which  is  formed 
hy  the  parietals  and  squarnosals.  An  upper  toothless  beak  is  formed  by  the  premaxillae 
together  with  a  median  "  rostral "  bone  corresponding  to  the  predentary  of  lower  jaw. 
Teeth  with  a  divided  root  fixed  in  socket s.  Vertebrae  amphiplat yan  ;  dorsal  centra 
extremely  short.  Limbs  nearly  equal ;  five  hoofed  digits  in  the  fore-,  three  in  the  hind- 
foot.     Dermal  armour  imperfectly  known. 

Most  of    the   forms   here  included  attain  gigantic  proportions,  and  are 


244 


KEPTILIA 


CLASS  III 


known  only  from  the  Uppermost  Cretaceous  (Laramie  Formation)  of  Mon- 
tana, Wyoming,  Colorado,  and  Dakota.  They  are  chiefly  remarkable  for 
the  armature  of  the  huge  skull,  the  strong,  pointed  horn-cores  of  which 
resemble  those  of  the  Bovidae.  Their  rugose  outer  surface  exhibits  distinct 
vascular  impressions,  and  was  doubtless  onee  sheathed  with  horny  tissue. 
Internally  they  are  hollow  at  the  base,  but  become  solid  higher  up. 

Triceratops,  Marsh  {Polyonax,  Jgathaumas,  Cope),  (Figs.  349,  350).     Skull 
over  rS  m.  long,  exceeding  in  size  that  of  any  known  land  aoimal.     Facial 

region  compressed  and  pointed,  hinder  half 
greatly  expanded  and  hood-like.  There  is 
a  sharp  cutting  beak  in  front,  a  strong  nasal 
horn-core,  a  pair  of  large  pointed  horns 
over  the  orbits,  and  a  row  of  sharp  pro- 
jections  around  the  margin  of  the  posterior 
hood.  External  nares  very  large,  placed 
between  the  nasals  and  rostral  bone.  Brain 
cavity  smaller  in  proportion  to  the  skull 
than  in  any  other  known  reptile.  Besides 
the  dentary,  which  develops  a  large  coronoid 
process,  an  articular,  angular,  surangular, 
and  splenial  are  distinguishable  in  the 
pjf,  34P  lower  jaw.     Atlas  and  axis  are  fused  with 

THceratopsserratiis,  M&rsli.   Upper  Cretaceous ;    the     next    Cervical     tO    SUpport     the    head  ; 
Montana,    Outer  (^),  and  lateral  (ß)  aspect  of    xi^        i.  luTuhars     and     first     four    raudals 

worn  maxillary  tooth,  Vi  (after  Marsh).  ^"®     ^^^0     lUmoars     aUQ     nrst    lOUr    cauaaib 

fused  with  the  sacrum,  which  has  double 
transverse  processes,  and  the  neural  canal  is  not  especially  enlarged.  Tail 
of  moderate  length,  chevron  bones  placed  intervertebrally.     The  small  per- 


FiG.  350. 
Iriceratops  proisus,  Marsh.     Upper  Cretaceous  ;  Montana.     Restoration  of  skeleton,  1/70  (after  Marsh). 


forated  coracoid  sometimes  fused  with  the  scapula  in  old  individuals.  Radius 
and  ulna  short  and  stout,  the  latter  with  large  olecranon  process ;  manus 
with  five  hoofed  digits.  Ilium  much  elongated ;  pubis  massive,  but  with 
slender  post-pubic  process.  Ischium  smaller  and  more  elongated  than  the 
pubis.  Femur  not  much  longer  than  the  humerus,  tibia  and  fibula  short,  the 
latter  very  slender.     Astragalus  usually  fused   with  distal  end   of  tibia ;  pes 


ORDER  VIII 


DINOSAURIA 


24/ 


with  three  hoofed  digits.     Dermal  armour  not  observed.     Laramie  Formation  ; 
Montana,  Wyoming,  and  Colorado. 

Cemtops  (MonodoniuSj  Cope),  Sterrholophus  (Fig.  351),   Torosaurus,  Marsh. 


Fig.  351. 
Sterrholophus  flabellatm,  Marsh.     Uppermost  Cretaceous  ;  Montana.     Lateral  and  superior  aspects  of  skull, 
1/20-    ^)  Orbit;  c,  Marginal  bosses  ("  epioccipital  plates");  /,  Brain  ;  h,  Horn-core ;  h\  Nasal  horn-core ;  N, 
External  narial  opening ;  n,  Nasal ;  p,  Parietal ;  pd,  Predentaiy  (restored  in  outline) ;  q,  Quadrate ;  7-,  Rostral 
bone  (restored  in  outline) ;  S,  Supratemporal  vacuity  ;  s,  Squaniosal  (after  Marsh). 

These  are  less  perfectly  known,  but  apparently  allied  genera  accompanying 
the  preceding  in  the  Laramie  Formation. 


Range  and  Distribution  of  the  Dinosauria. 

The  remarkable  and  by  no  means  homogeneous  group  of  Dinosauria  arose 
during  the  Trias,  attained  its  maximum  development  in  the  Upper  Jura  and 
Cretaceous,  and  passed  entirely  away  at  the  close  of  the  latter  period.  The 
abundance  of  Dinosaurs  during  the  Trias  is  indicated  by  countless  footprints 
in  the  sandstones  of  that  age  in  Massachusetts,  Connecticut,  Pennsylvania, 
Virginia,  and  North  Carolina,  where  hordes  of  these  creatures  roamed  along 
the  beaches  in  quest  of  prey.     Upwards  of  100  difFerent  varieties  of  footprints 


246 


REPTILIA 


CLAS8  III 


have  beeil  discovered  in  the  Connecticut  Valley,  varying  between  2 '5  cm.  and 
60  cm.  in  length.  Most  of  these  imprints  are  three-toed,  although  four-  and 
five-toed  tracks  also  occur,  and  their  paths  are  often  traceable  for  a  number  of 
meters.  Since  many  of  these  indicated  creatures  of  bipedal  gait,  early  writers 
(notably  Hitchcock  in  1837  and  1858)  very  naturally  attributed  them  to 
birds,  and  designated  them  by  various  names.  The  paucity  of  skeletal  remains 
in  the  strata  where  footprints  are  so  conspicuous  a  feature  is  remarkable. 

The  earliest  known  Dinosaurs  belong  to  the  carnivorous  group  of  Theropoda, 
and  are  extremely  generalised.  Their  obvious  relations  to  the  Bhynchocephalia, 
Crocodiliay  and  Theromorpha  have  already  been  discussed,  and  attention  directed 
to  avian  resemblances  pervading  both  this  and  the  herbivorous  sub-orders.  It 
need  only  be  repeated  in  this  connection  that,  in  spite  of  the  remarkable  simi- 
larity  between  birds  and  Dinosaurs,  there  is  no  evidence  to  prove  that  the 
former  have  come  down  to  us  through  any  known  type  of  the  latter.  And 
yet  it  would  appear  rather  more  probable  that  the  avian  phylum  should  have 
originated  from  primitive  Dinosaurs — that  is  to  say,  from  a  Dinosaur-avian 
stem,  than  that  the  two  groups  arose  independently  from  some  common  stock. 

TABLE  SHOWING  VERTICAL  RANGE  OF  THE  DINOSAURIA. 


Families.                            • 

1 

i 
*  1 1 

1  'B 

1    1 

5 

t 

Theiiopoda 

1.  Megalosauridae 

2.  Compsognathidae 

3.  Goeluridae ....... 

Sauhopoda. 

1.  Gamarasaurida  c 

2.  Diplodocidae 

PllEDENTATA 

1.  Iguanodontida  c 

2.  Stegosauridae 

3.  Ceratopsidae 

..  .. 

i 

1 

{ 

1 

j 

1 

i 
1 

1 

..?.. 

1 

1 

j 
i 

1 


[The  text  for  the  introductory  portion  of  the  preceding  chapter  on  Dinosaurs  lias  been 
revised  to  a  slight  extent  by  Professor  H.  F.  Osborn ;  that  for  the  systematic  part  has  been 
revised  by  Mr.  J.  B.  Hatclier,  of  the  Carnegie  Museum  at  Pittsburgh. — Editor.] 


Order  9.     PTEROSAURIA.     Kaup.     (Ornithosanria,  Fitzingery 

Reptiles  of  more  or  less  hird-like  aspect,  with  hollow  hones,  well-formed  articula- 
Hons,   aiul  fore-Umhs    adapted  for  flighf.     Skull  with  acuminate  snout,   and   long 

^  Literature  : 

Burmeister,  JI.,  Kritische  Beleuclitung  der  Pterodactylus-Arten  (Sitzungsber.  naturf.  Gesellsch. 
Halle,  vol.  III.),  1855. — Fraas,  0.,  Ueber  Pterodactylus  suevicus  (Palaeontogr.  vol.  XXV.  p.  163), 
1878. — Goldfuss,  A.,  Reptilien  ans  dem  lithographischen  Schiefer  (Nova  Acta  Acad.  Leop.  vol.  XV. 


ORDER  IX  PTEROSAUKIA  247 

axis  extemling  nearly  at  right  angles  with  the  neck  Invesfing  hones  of  temporal 
region  contracting  into  an  upper  and  a  lower  arcade  ;  sutures  becoming  obliterated  in 
the  adult.  Quadrate  large,  firmly  fixed  ;  orbit  very  lavge,  and  usually  with  sclerotic 
ring  ;  antorbital  vacuity  large,  sometimes  confiuent  with  external  nares.  Teeth,  when 
presenf,  slender,  conical,  thecodont,  and  confined  to  margin  of  the  jaws.  Mandibular 
rami  fused  at  the  Symphysis.  Presacral  vertebrae  procoelous,  caudals  amphicoelous  ; 
sacrals  four  to  seven  in  nurnber,  usually  fused.  Cervical  and  anterior  dorsal  ribs  double- 
headed.  Sfernum  large,  clavicular  elements  waiding,  scapula  ano^  coracoid  long  and 
slender.  Fifth  digit  of  manus  enormously  elongated  aiul  reflexed  to  support  the  wing 
membrane.  Pubis  excluded  from  the  closed  acetabulum.  Both  rows  of  tarsals  ossified, 
the  astragalus  sometimes  fused  with  the  tihia,  Two  to  four  digits  of  the  pes  bear  claws, 
the  fifth  digit  sometimes  vestigial.     Abdominal  ribs  present ;  no  dermal  armour. 

The  Pterosauria  or  Ornithosauria,  as  they  are  also  called,  constitute  an 
extraordinary  group  of  extinct  reptiles,  rangirjg  from  the  Lias  to  the  Upper 
Cretaceous.  They  are  remarkably  bird-like  in  general  appearance,  and 
their  whole  Organisation  is  modified  for  the  accomplishment  of  fiight  through 
the  air.  In  the  larger  nurnber,  however,  the  power  of  fiight  was  more  limited 
than  in  birds,  and  may  have  been  in  many  forms  feebler  than  in  bats.  The 
skeleton  was  more  or  less  pneumatic,  like  that  of  birds,  and  the  general 
avian  appearance  was  accentuated  by  the  articulation  of  the  head  at  right 
angles  to  the  cervical  axis.  Some  of  these  bizarre  creatures  were  no  larger 
than  sparrows,  but  others,  with  whose  extinction  the  history  of  the  race 
terminates,  were  of  gigantic  size,  the  spread  of  their  cutaneous  expansion 
being  nearly  6  m.  from  tip  to  tip. 

The  vertebral  column  comprises  seven  true  cervicals,  twelve  to  sixteen 
dorsals,  four  to  seven  sacrals,  and  ten  to  forty  caudals.  The  presacral  vertebrae 
are  procoelous,  and  the  caudal  amphicoelous.  The  neural  arches  are  usually 
fused  with  their  centra,  and  the  sides  of  the  latter  are  more  or  less  extensively 
hollowed.  Cervical  ribs,  when  present,  are  very  much  shorter  than  the  dorsal 
ribs.  The  latter  are  double-headed  anteriorly,  but  become  single-headed  and 
more  slender  toward  the  sacral  region.  Transverse  processes  are  very  strongly 
developed  in  the  anterior  sacral  vertebrae.  There  is  a  triple  series  of  small 
V-shaped  abdominal  ribs  along  the  ventral  wall  of  the  body  cavity. 

The  sJmll  (Fig.  352)  is  remarkably  bird-like  in  form,  and  its  constituent 
elements  usually  become  anchylosed  at  an  early  age.  The  orbits  are  very 
large,  laterally  placed,  and  surrounded  by  a  sclerotic  ring  of  small  plates.    An 

p.  63),  1831. — Hvxley,  T.  H.,  On  Rhampliorhynchus  Bucklandi  (Quar.  Jouni.  Geol.  Soc.  vol.  XV. 
p.  658),  1860. — Marsh,  0.  C,  Various  articles  in  Amer.  Journ.  Sei.  [3],  1871-84  (vols.  I.  p.  472  ; 
III.  p.  241  ;  XI.  p.  507  ;  XII.  p.  479  ;  XVI.  p.  233  ;  XXI.  p.  342  ;  XXIII.  p.  251  ;  XXVII.  p. 
423,  etc.). — Meyer,  U.  van,  Reptilien  aus  dem  lithographischen  Schiefer  (Faunader  Vorwelt,  pt.  IV.), 
1860. — Xewton,  E.  T.,  On  the  skull,  brain,  and  anditory  organ  of  Scaphognathus  purdoni  (Phil. 
Trans,  vol.  CLXXIX.  B,  p.  503),  1888.— Notes  cn  Pterodactyles  (Proc.  Geol.  Assoc.  vol.  X.),  1888. 
— Owen,  Tl.,  Reptilia  of  tlie  Liassic  Formations  ( Palaeontogr.  Soc.  pt.  II.),  1863. — PUeninffer,  F., 
Campylognathus  Zitteli  (Palaeontogr.  vol.  XLT.),  1894.— Beiträge  zur  Kenntniss  der  Flugsaurier 
{ibüi.  vol.  XliVIII.),  1901.— Qnenstedt,  F.  A.,  lieber  Pterodactylus  suevicus.  Tübingen,  1855. 
— Seeley,  H.  (r.,  The  Ornithosauria,  Cambridge,  1870. — On  the  Organisation  of  the  Ornithosauria 
(Journ.  Linn.  Soc.  vol.  XIII.),  1884.— The  Ornithosaurian  pelvis  (Ann.  Mag.  Nat.  Hist.  [6],  vol. 
VII.  p.  237),  1891. — On  the  shouMer-girdle  in  Cretaceous  Ornithosauria  (iä/(/.  p.  438).— Dragons 
of  the  Air,  London,  1901. —  Wagner,  A.,  Contributions  on  Upper  Jurassic  Pterosaurs  in  Abhaudl. 
Bayer.  Akad.  Wissensch.  math.-phys.  Classe,  vols.  II.  p.  163;  VI.  pp.  129,  690;  VIII.  p.  439 
(1837-58).  —  WilUston,  Ä  W.,  On  the  skiül  of  Ornithostoma  (Kansas  Univ.  Quar.  vol.  IV.  p.  195), 
1896.  — Restoration  of  Ornithostoma  (Pteranodon),  {ibid.  vol.  VI.  p.  35),  1897. — Zittel,  K.  A., 
Ueber  Flugsaurier  aus  dem  lithograpliischen  Schiefer  (Palaeontogr.  vol.  XXIX.  p.  49),  1882. 


248 


EEPTILIA 


CLASS  III 


Fio.  352. 

Scaphognathus  crassirostris,  Goldf.  sp.  Upper  Jura ;  Eichstädt,  Bavaria. 
D,  Antorbital  vacuity ;  fr,  Frontal ;  ju,  Jugal ;  vw,  Maxiila ;  N,  Narial  opening  ; 
pvtx,  Premaxilla  ;  qu,  Quadrate. 


antorbital  vacuity  is  present  as  in  birds  and  Dinosaurs,  and  is  either  confluent 
with  the  external  nostril  on  each  side,  or  separated  from  it  by  a  narrow  bar. 
The  supratemporal  vacuity  is   small,  entirely  enclosed,  and   placed   far   back- 

wards.  The  lateral 
temporal  vacuity 
appears  as  a  narrow 
slit  behind  the  orbit, 
extending  downward 
and  forward,  and 
bounded  posteriorly 
by  the  quadrate. 
The  cranial  roof  is 
formed  by  the  un- 
paired  frontal  and 
the  smaller  parietals, 
which  are  without 
a  foramen.  At  the 
base  of  the  skull  is  placed  the  single  occipital  condyle,  by  means  of  which 
the  head  is  carried  approximately  at  right  angles  to  the  long  axis  of  the  neck. 
Natural  casts  of  the  brain  cavity  prove  it  to  have  been  remarkably  bird- 
like,  though  smaller  in  proportion  to  the  size  of  the  skull.  It  was  entirely 
roofed  by  the  frontal  plate,  which  sometimes  extended  as  far  forwards  as  the 
anterior  border  of  the  orbits,  and  formed  not  only  their  upper,  but  also  a  part 
of  their  posterior  border.  The  orbit  is  separated  from  the  lateral  temporal 
vacuity  by  a  trifid  post-frontal  plate,  one  brauch  of  which  joins  the  squamosal, 
and  forms  at  the  same  time  the  outer  bar  of  the  supratemporal  vacuity.  The 
orbit  is  bounded  anteriorly  by  slender  processes  of  the  jugal  and  prefrontal, 
which  meet  each  other  half-way,  both  of  these  plates  being  small  and 
triangulär.  The  quadrate  is  a  relatively  long  and  narrow  bar,  united  with  the 
squamosal  above,  and  with  a  buttress  of  the  pterygoid  below.  In  the  facial 
region,  which  closely  resembles  that  of  birds,  sutures  are  always  difficult  to 
determine.  The  snout  is  pointed  in  front,  or  in  some  cases  slightly  rounded, 
and  is  formed  by  the  enlarged  premaxillae,  which  constitute  the  greater  part 
of  the  Upper  jaw.  Teeth,  when  present,  occur  in  single  series  at  more  or  less 
irregulär  intervals  along  the  margin  of  the  jaws.  They  are  invariably  simple 
and  conical,  and  implanted  in  distinct  sockets.  In  some  genera  the  sharp 
margins  of  the  jaws  are  completely  edentulous,  and  may  have  been  sheathed 
with  a  horny  layer,  as  in  birds. 

The  mandibular  rami  are  straight  and  elongate,  and  fused  together  at  the 
Symphysis.  They  are  composed  of  the  usual  six  elements,  but  the  sutures 
between  the  latter  are  seldom  determinable.  A  coronoid  process  is  lacking, 
and  the  Suspensorium  is  sometimes  inclined  forwards  at  a  considerable  angle, 
so  that  the  articulation  with  the  quadrate  is  placed  underneath  the  orbits. 

The  pedoral  arch  comprises  merely  a  pair  of  long,  narrow  scapulae,  and 
equally  long  but  somewhat  stouter  and  imperforate  coracoids,  which  articulate 
with  the  large  sternum  by  a  synovial  Joint.  There  is  no  clavicular  arch,  nor 
any  indication  of  precoracoid  elements.  The  humerus  is  of  moderate  length, 
much  expanded  proximally,  and  exhibits  a  deltoid  crest.  The  axis  of  the 
distal  articular  facette  is  approximately  at  right  angles  to  that  of  the  head  of 
the  same  bone.     Kadius  and  ulna  sometimes  doubly  exceed  the  length  of  the 


ORDER  IX 


PTEROSAUKIA 


249 


humerus,  and  are  about  equally  developed.  The  number  of  carpal  elements 
in  both  rows  varies  considerably.  The  first  digit  of  the  manus  is  either  wanting 
or  represented  by  a  backwardly  directed  styliform  bone.  The  second,  third, 
and  fourth  metacarpals  are  closely  apposed  and  nearly  uniform  in  size,  but 
the  fifth  is  very  much  stouter  than  the  rest,  and  bears  a  series  of  four  enor- 
mously  elongated  phalanges,  turned  backward  to  support  the  wing-membrane. 
Sometimes  metacarpals,  Nos.  ii  to  iv  are  incomplete,  and  either  filiform  or 
tapering  to  a  point  proximally,  being  fixed  only  to  the  side  of  the  greatly 


Fig.  353. 

RhamphorhyncJms  phyllurus,  Marsh.     Upper  Jura  (Lithographie  Stoiie) ;  Bavaria.     Restoration, 

showing  extent  of  cutaneous  expansions,  1/7  (froiii  A.  S.  Woodward,  after  Marsh). 

developed  metacarpal  of  the  wing-digit.  The  three  inner  digits  are  clawed 
and  exhibit  the  phalangeal  formula  2,  3,  4.  They  are  entirely  free  from  the 
membranous  expansion  of  the  fifth  digit  (Fig.  353).  Attached  to  the  radial 
side  of  the  carpus  is  sometimes  observed  a  slender  splint-like  bone,  which  is 
directed  backward  nearly  parallel  with  the  radius  and  ulna.    This  is  the  so-called 


Fig.  354. 

Rhamphorhynchus  gemmingi,  v.  Meyer.  Ui)per  Jura  (Litliographic 
Stone);  Bichstadt,  Bavaria.  Right  fore-linib  with  impression  of  volant 
niembrane. 


"  pteroid  bone  "  (SpannJcnochen,  von  Meyer),  which  some  writers  have  regarded 
as  an  ossified  tendon,  or  as  a  support  for  the  wing  membrane ;  but  it  is  more 
properly  interpreted  as  a  rudimentary,  abnormally  reflexed  first  metacarpal. 
The  cutaneous  expansion,  or  patagium  (Fig.  354),  is  quite  narrow  and  tapering, 
in  this  respect  resembling  the  wing  of  a  swallow  or  sea-gull.  It  was  attached 
at  its  base  along  the  sides  of  the  body  wall,  and  extended  beyond  the  bind 
limbs  to  the  base  of  the  tail.  In  at  least  one  genus  {Rhamphorhynchis)  it  also 
developed  a  leaf-like  expansion  at  the  extremity  of  the  tail  (Fig.  353).     The 


250 


REPTILIA 


CLASS  IIT 


ja-..'^^| 


Fig.  355. 


impressioiis  of  the  membrane  exhibit  a  number  of  longitudinal  wrinkles  or 

folds,  and  also  numerous  fine  parallel  Striae, 
but  are  othervvise  smooth. 

In  the  pelvic  arch  (Figs.  355,  356)  the 
ilium  is  low  and  extended  antero-posteriorly 
on  either  side  of  the  imperforate  acetabulum 
as  in  Dinosaurs,  the  pre-acetabular  portion 
<X  being  much  longer  than  the  post-acetabular. 

N^"-^;:;^;^  Its    anterior    extremity    is    sometimes    ex- 

panded    (Bhamphorhi/nchus),   in   other   cases 
slender   and   tapering   {Pterodadylus).     The 

Pta-cMctvlus  antiguns,  Söm:n.  sp.  Upper  ischium  USUally  fuses  with  the  ililim,  and 
Jura ;  Bavaria.  Right  lateral  aspect  of  pelvis.  excludes  the  Dubis  from  the  acetabulum  : 
a,    Acetabulum,    belovv    which    is    obturator     .  ^        ^  iii  •  i- 

foramen ;  ii,  Ilium ;  is,  ischium ;  pw,  Pubis.       it  is  a  much-expanded  bone,  pierced  in  most 

cases  by  a  small  Perforation.  The  pubis 
appears  to  have  been  very  loosely  attached  to  the  antero-inferior  portion  of 
the  ischium,  and  almost  invariably  occurs  dis- 
placed.  Some  authors  regard  this  bone  as  a 
pre- pubis,  and  Interpret  the  posterior  ventral 
Clement  as  a  fused  ischio-pubis.  In  Pterodadylus 
the  bone  here  called  the  pubis  is  much  expanded 
distally,  and  was  probably  united  with  its  fellow 
in  a  cartilaginous  Symphysis.  But  in  Bhampho- 
rhi/nchus, Pteranodon,  and  Nydodadylus,  it  is 
narrow  and  band-like,  extending  forwards  for  a 
certain  distance,  and  then  beut  inwards  approxi- 
mately  at  right  angles  so  as  to  meet  its  fellow 
of  the  opposite  side,  with  which  it  becomes  fused 
in  a  ventral  Symphysis. 

The  femur  is  rather  longer  and  more  slender 
than  the  humerus  in  some  forms,  but  in  others 
is  very  much  shorter,  as  in  birds  ;  and  as  in  birds 
also,  it  is  exceeded  in  length  by  the  tibia,  which 
is  stout  and  straight.  The  fibula  is  reduced  to 
a  mere  splint,  often  fused  with  the  tibia,  and  its 
pointed  distal  end  extending  scarcely  half-way 
down  the  shaft  of  the  tibia,  or  it  may  be  absent 
altogether.  There  are  two  proximal  tarsals 
(astragalus  and  calcaneum),  which  in  the  Phampho- 
rhyndiidae  and  Ornifhocheiridae  are  always  fused 
with  the  tibia.  At  least  two  distal  tarsals  are 
always  present. 

The  bind  foot  is  characteristically  reptilian 
in  structure.  The  four  inner  metatarsals  are 
abtout  equally  developed,  and  bear  clawed 
phalan^es,  havinsr  the  formula  2,  3,  4,  5,  or  some-      „,      ,.   ^     ^  .    .     «„„„,. 

times,   when    the    lirst  two  dlgltS  are  clawleSS,  the    Upper  Jura;   Eichstädt,  Bavaria.    Vi- 
r  1      •      1      n      ^      K         rriu       iiTi-i,     J '    '  i.     •         1  i.    f,  Femur ;  ü,  Ilium;  is,  Ischium;  pf, 

lormula  is  1,  2,  4,  5.      Ihe  nfth  digit  is  almost   pubis ;  ^  Tibia. 

always    shorter    than    the    rest,    its    metatarsal 

reduced  to  a  mere  stump,  sometimes  without  phalanges,  and  sometimes  with 


Fig.  356. 


ORDER  IX 


PTEROSAURIA 


251 


as  many  as  three.  In  Rhamphorhynchus  and  Dimorphodan  it  was  divaricated, 
and  doubtless  assisted  in  the  support  of  the  patagium.  The  claws  are  usually 
sharp  and  delicate,  and  during  life  were  doubtless  sheathed  with  hörn. 

Sub-Order  1.     PTERODERMATA.     Seeley. 

2\iil  elongated ;  wing  metacarpal  less  than  half  the  length  of  the  boTies  of  the 
antehrachiiim  ;  fifth  digit  of  pes  with  one  to  three  phalanges.  Jaws  dentigerous  ; 
external  nares  completely  separat  ed  fr  am  antorbital  vacuity. 

This  group  comprises  the  earlier  and  more  generalised  Pterosaurs,  none  of 
which  survived  the  Jurassic  so  far  as  known.  Teeth  are  always  present, 
increasing  in  size  posteriorly,  but  sometimes  do  not  extend  to  the  anterior 
extremity  of  the  jaws.  The  scapulae  and  coracoids  are  often  fused  proximally, 
and  the  proximal  tarsals  are  fused  with  the  tibia. 

Family  1.     Rhamphorhynchidae. 

With  the  characters  of  the  sub-m'der.     Jurassic. 

Dimorphodon,  Owen  (Fig.  357).  Skull  relatively  very  large,  deepened  in 
form,   and   extremely   light ;    brain  case   unusually   small.      External   narial 


Fio.  357. 

Diniorplwdon  macronyx,  Owen.     Lower  I.ias  ;  Dorsetshire.     Restoration  of  skeleton,  i/;. 

-,  Antorbital  vacuity  ;  »,  Extfinal  narial  opening ;  o,  Orbit  (from  A.  S.  Woortward,  after  Owen). 

openings  and  antorbital  vacuities  very  large.     Jaws  toothed  to  the  extremity, 
the  anterior  teeth  very  large  and  irregularly  spaced  ;  mandibular  Suspensorium 


252 


EEPTILIA 


CLASS  III 


vertical.  Probably  four  sacrals,  and  at  least  thirty  caudals  present,  some  of 
the  latter  with  chevroii  bones.  Scapula  and  coracoid  fused.  First  digit  of 
manus  represented  by  a  styliform  ("pteroid")  bone,  and  first  wing  phalanx 
shorter  than  the  antebrachium.  Ischium  large,  distally  expanded.  The  iirst 
four  clawed  digits  of  the  pes  are  normal,  and  the  fifth  divaricated ;  the  latter 
with  an  attenuated  metatarsal  and  two  phalanges.     The  skull  of  D.  macronyx, 


Fig.  358. 

Rtiamphorhyrnhus  gemmingi,  v.  Meyer.  Lithographie  Stone  ;  Eichstädt,  Bavaria.  A,  Orbit ;  D,  Antorbital 
vacuity  ;  N,  External  narial  opening  ;  pmx,  Premaxilla ;  r,  Rib  ;  S,  Lateral  temporal  vacuity  ;  S',  Supratemporal 
vacuity ;  st,  Sternum. 

Owen,  the  only  described  species,  attains  a  length  of  20  cm.  Lower  Lias ; 
Dorsetshire. 

Dorygnathus,  Oppel.  Upper  Lias  ;  Würtemberg  and  Franconia.  Bhampho- 
cephalus,  Seeley.     Bathonian  ;  Stonesfield,  England.     Imperfectly  known  genera. 

Campylognathus,  Plien.  Known  by  a  complete  skeleton  from  the  Upper 
Lias  of  Holzmaden,  Würtemberg.  Skull  less  deep  than  in  Bimorphodon, 
toothed  to  the  extremity  of  the  jaws ;  the  anterior  tooth  above  and  the  first 
two  below  large  and  recurved.  Mandibular  rami  toothed  nearly  to  the 
extremity,    which  is  deflected   downward.      Narial   opening   larger  than  the 


ORDER  IX  PTEROSAURIA  253 

antorbital  vacuity.  Proximal  phalanx  of  wing  digit  more  than  double  the 
length  of  antebrachium.  Type,  C.  zitteli,  Plieninger.  Palate  and  brain  cast 
4inown  in  C.  purdoni,  Newton,  from  the  Upper  Lias  of  Yorkshire. 

ScaphognathuSj  Wagner,  Like  the  preceding,  but  mandibular  rami  toothed 
quite  to  the  extremity,  and  not  defiected.  External  nares  smaller  than  the 
antorbital  vacuity.  S.  crassirostris,  Goldfuss,  the  type  species,  occurs  in  the 
Lithographie  Stone  of  Bavaria. 

Bhamphorhynchus,  v.  Meyer  (Figs.  354,  356,  358).  Skull  sometimes  attain- 
ing  a  length  of  20  cm.  Snout  produced  and  acuminate ;  teeth  large,  irregulär, 
inclined  forwards,  and  not  extending  to  anterior  end  of  the  jaws.  Orbits  very 
large,  with  sclerotic  ring ;  narial  opening  and  antorbital  vacuity  very  small. 
Four  sacrals  and  upwards  of  forty  caudals  present.  Sternal  keel  extending 
downward  as  a  slender  process,  scapula  and  coracoid  usually  fused.  Pubis  in 
the  form  of  a  slender  bar,  bent  inwards  nearly  at  right  angles  to  meet  its 
fellow,  with  which  it  fuses  in  a  median  Symphysis.  Limbs  similar  to  those  of 
Dimorphodon,  except  that  the  fifth  toe  comprises  three  phalanges.  Upper 
Jura  (Lithographie  Stone) ;  Bavaria  and  Würtemberg. 

Sub-Order  2.     ORNITHOCHEIROIDEA.     Seeley. 

Tau  short;  wing  metacarpal  at  least  as  long  as  the  bones  of  the  antebrachium;  fifth 
digit  of  pes  vestigial,  without  phalanges.     Teeth  sometimes  absent.     No  cervical  ribs. 

The  members  of  this  sub-order  vary  greatly  in  size,  some  being  no  larger 
than  a  sparrow,  and  the  largest  having  a  wing  expanse  of  nearly  6  m. 
Initiated  in  the  Upper  Jura,  the  group  culminated  in  the  Upper  Cretaceous, 
and  became  extinct  before  the  close  of  that  period.  This  sub-order  probably 
includes  all  knovvn  forms  of  Cretaceous  Pterosaurs. 

Family  1.     Pterodactylidae. 

Skull  with  very  snudl  lateral  temporal,  vacuities,  and  large  external  nares  iiuom 
pletely  separated  from  the  q/ntorbital  vacuity.  Coracoid  aiid  scapula  separated,  the 
distal  end  of  the  latter  spatulate,  and  not  articulating  with  vertebral  column.  Anterior 
dorsal  vertebrae  without  supraneural  plate.  Elements  of  carpus  and  tarsus  distinct. 
Teeth,  when  present,  extending  to  extremity  of  jaws.     Upper  Jura  and  Cretaceous. 

Fterodactylus,  Cuvier  (Ornithocephalus,  p.p.  Sömm.  ;  Diopecephalus,  Cycno- 
rhamphus,  Seeley;  Ftenodracon,  Lyd.),  (Figs.  355,  359,  360).  Teeth  invariably 
present.  Eepresented  by  numerous  species  varying  in  size  between  that  of  a 
sparrow  and  that  of  an  eagle.  The  most  perfectly  preserved  skeletons  occur 
in  the  Lithographie  Stone  of  Bavaria,  Würtemberg,  and  Cerin,  France. 
Certain  detached  fragments  from  the  Kimmeridge  Clay  of  England  are  perhaps 
referable  to  this  genus. 

Nyctodactylus,  Marsh  (Fig.  361).  Known  by  a  nearly  complete  skeleton  from 
the  Niobrara  Cretaceous  of  Kansas.  Head  slender,  jaws  edentulous.  Lateral 
pieces  of  atlas  not  fused  with  axis ;  cervicals  seven,  dorsals  twelve,  sacrals 
six,  caudals  ten  to  fourteen.  Anterior  ribs  stout,  double-headed ;  posterior 
very  slender  and  single-headed ;  three  pairs  of  flat  V-shaped  abdominal  ribs 
connecting  the  xiphisternal  process  with  the  anterior  processes  of  the  coössified 
pubes.  Ischiadic  foramen  very  large.  Proximal  row  of  tarsals  united  to  tibia 
by  persistent  suture  ;  three  carpals  present.  Wing  expanse  in  typical  species 
about  2  m. 


254 


REPTILIA 


CLASS  III 


Dermodadylm,  Marsh.     Imperfectly  known,  perhaps  belonging  among  the      ^ 
Pterodermata.     Upper  Jura  (Como  Beds) ;  Wyoming. 


Fio.  359. 

J'terodactijlus  elegans,  Wagner.     Lithographie  Stone  ; 

Eichstäclt,  Bavaria.     Vi- 


Fig.  360, 

Pterodactyhis  spectabüis,  v.  Meyer.     Lithographie 
Stone  ;  Eichstädt,  Bavaria.     '-^/^  (after  H.  v.  Meyer) 


Family  2.     Ornithocheiridae.      Seeley. 

External  nares  confluent  with  antorbital  vacuity.  Teeth,  when  present,  restrided 
to  posterior  portimi  of  the  jaws.  Pectoral  arch  strong,  coracoids  and  scäpulae  firmly 
fused ;  the  former  articulating  with  the  sternum,  and  the  latter  hy  a  large  oblique 
facette  with  a  supraneural  plate  above  the  coössified  anterior  dorsal  verlebrae.  Proxi- 
mal tarsals  fused  with  the  tibia;  no  fibula.     Cretaceous. 

This  family  includes  the  largest  known  Pterosaurs,  their  wing  expanse 
varying  between  \'b  and  5 '8  m.  In  these  highly  specialised  forms  the  anterior 
extremities  attained  their  greatest  power,  while  the  posterior  pair  were 
weakened,  and  probably  of  slight  use  as  locomotive  orgaiis. 

Fteranodon,  Marsh  (?  Ornithostoma,  Seeley).  Skull  considerably  elongated, 
with  slender,  pointed,  edentulous  jaws,  and  a  long  thin  supraoccipital  crest. 
Sclerotic  ring  present.  Sternum  keelless,  but  with  a  stout  anterior  median 
projection.  Sacral  vertebrae  seven  in  number.  Anterior  ribs  stout, 
coössified  with  their  centra.  Carpus  composed  of  three  bones  in  two  rows. 
Pubes  band-like,  coössified  in  the  middle.  Hind  limbs  relatively  small ; 
femur  short  and  curved,  with  a  small  trochanter ;  tarsus  consisting  of  two 
free  bones  in  a  single  row.  Fifth  digit  represented  by  a  small  claw-like 
metatarsal ;  median  phalanges  of  second,  third,  and  fourth  digits  very  short ; 
first    and    second    digits    without    claws.       Niobrara     Cretaceous ;    Kansas. 


ORDER  IX 


PTEROSAURIA 


255 


Ornithostoma,   Seeley,   from  the   Cambridge    Greensand,   presents    no  generic 
difFerences  from  Fteranodon  so  far  as  known,  and  may  prove  to  be  identical. 

Ornithocheirus,  Seeley.  Similar  in  all  essential  respects  to  Pteranodmi, 
except  for  the  presence  of  well-developed  teeth  in  both  jaws.  Pelvis  and  bind 
limbs  imperfectly  known.     Cambridge  Greensand  ;  England. 


Fig.  361. 
Nyctodactylns  gracllis,  Marsh.     Niobrara  Cretaceoiis  ;  Kansas.     1/9  (after  WillistonX 

Ornithodesmus,  Doi^aiorhynchus,  Seeley ;  Palaeornis,  Mantell.  Founded  on 
fragmentary  remains  from  the  Wealden  and  Purbeck  of  England. 

Range  and  Phylogeny  of  the  Pterosauria. 

The  earliest  undoubted  remains  of  Pterosaurs  occur  in  the  Lower  Lias  of 
England,  from  which  horizon  the  history  of  the  group  is  traceable  to  near  the 
close  of  the  Mesozoic  era.  Eegarding  its  origin  and  evolution  very  little  can 
be  affirmed.  Dimorphodon,  the  oldest  known  genus,  appears  suddenly  and  fully 
difFerentiated  in  the  same  manner  as  do  the  earliest  Chelonians ;  nor  are  there 
any  essential  modifications  to  be  observed  among  its  successors  throughout  the 
Jura  and  Cretaceous,  except  that  some  of  the  latest  survivors  were  toothless 
and  of  gigantic  size.  The  group  attained  its  maximum  development  during 
the  Upper  Cretaceous,  and  passed  away  with  the  Dinosaurs,  Pythonomorphs, 
and  Plesiosaurs  towards  the  close  of  this  period. 

Although  Pterosaurs  exhibit  a  number  of  avian  resemblances,  they  can  in 
no  sense  be  regarded  as  the  ancestors  of  birds,  and  are  in  fact  even  more  widely 
separated  from  them  than  from  other  Orders  of  reptiles.  They  are  known  to  us 
simply  as  a  race  of  peculiarly  modified  Archosauria,  or  reptiles  with  two  temporal 
iirches,  whose  origin  is  as  yet  mysterious,  and  whose  hypertropic  specialisation 
precipitated  their  decline,  and  finally  swept  them  from  off  the  face  of  the  earth. 

[The  text  for  the  preceding  chapter  on  Pterosauria  has  beeu  revised  by  Dr.  S.  W.  Williston, 
of  the  University  of  Kansas,  who  has  also  put  the  chapters  on  Pythonomorphs  and  Plesiosaurs 
in  their  present  shape.— Editor.] 


256  EEPTILIA 


Class  4.    AVES.    Birds.i 


CLASS  III 


Feathered,  warm-hlooded,  oviparous  vertebrates  with  Chambers  of  the  heart 
completely  separated.  There  is  a  single  occipital  condyle,  the  quadrate  is  free,  and 
the  fore-limhs  are  modified  into  wings.  Proximal  tarsals  fused  with  tibia  to  form  a 
tibio-tarsiis ;  metapodal  bones  fused  with  one  another,  and  with  the  distal  tarsals  to 
form  a  tarso-metatarsus.     Fifth  digit  of  the  pes  always  absent. 

Of  all  classes  of  vertebrates,  birds  constitute  the  most  homogeneous  and 
narrowly  ^ircumscribed  group,  and  exhibit  everywhere  the  most  remarkable 
uniformity.  Descended  without  question  from  reptiles,  their  affinities  with 
that  class  are  so  intimate  that  Huxley  included  them  both  under  the  common 
designation  of  Sauropsida.  This  proposed  merging  of  the  two  classes,  however, 
is  hardly  compatible  with  such  trenchant  distinguishing  characters  as  the 
epidermal  covering  of  feathers,  heterocoelous  vertebrae,  and  warm  -  blooded 
(homothermic)  condition. 

The  exoskeleton  of  birds  consists  of  feathers,  the  horny  covering  of  the  beak, 
claws,  and  spurs,  and  certain  corneous  plates  often  found  on  the  tarsus  and 
feet.  Save  in  penguins  the  feathers  do  not  cover  the  body  uniformly,  but 
are*  arranged  in  certain  definite  tracts  (pterylae),  between  which  are  bare 
Spaces  (apteria).  These  apteria  are  best  seen  on  the  abdomen  and  on  the 
sides  of  the  neck  in  many  birds.  Although  struthious  birds  are  also  com- 
monly  said  to  be  uniformly  covered  with  feathers,  Pycraft  has  shown  the 
presence  of  small  apteria  in  most  species.  Under  exceptionally  favourable 
conditions,  as  in  the  Lithographie  Stone  of  Bavaria,  and  the  Green  Eiver 
Eocene  of  Wyoming,  imprints  of  feathers  may  be  preserved  in  the  rocks. 

The  skeleton  of  birds  is  remarkable  for  its  combination  of  compactness  and 
lightness,  and  for  its  pneumaticity,  or  permeation  by  air  cavities.  The  walls 
of  the  bones  are  very  thin,  but  of  dense  texture,  owing  to  their  richness  in 
calcium  phosphate.  In  young  birds  the  cavities  of  the  long  bones  are  filled 
with  marrow,  and  this  may  persist  in  some  bones  throughout  life,  as  in  a 
number  of  water  birds ;  on  the  other  band,  the  marrow  may  disappear  and 
the  interstices  become  filled  with  air,  as  in  the  long  bones  of  birds  which 
sail  or  soar,  and  many  others ;  finally,  the  long  bones  may  be  completely 
filled  with  spongy  bone  or  cancellar  tissue,  as  is  the  case  with  penguins. 
The  skull,  humerus,  and  femur  may  be  said  to  be  pneumatic  in  the  majority 
of  birds. 

The  vertebral  column  of  birds  is  divisible  into  cervical,  dorsal,  sacral,  and 

^  Literature  : 

Beddard,  F.  E.,  The  structure  and  Classification  of  Birds.  London,  1898. — Fürhringer,  M., 
Untersuchungen  zur  Morphologie  und  Systematik  der  Vögel.  Amsterdam,  1888. — Ruxley,  T.  H., 
On  the  Classification  of  Birds  (Proc.  Zool.  Soc.  London,  p.  415),  1867. — Lydekker,  li.,  Catalogue  of 
fossil  Birds  in  the  British  Museum.  London,  1891. — Marsh,  0.  C,  Odontornithes :  a  monograph 
of  the  extinct  toothed  Birds  of  North  America.  Washington,  1880. — Meyer,  A.  B.,  Abbilddungen 
von  Vogel-Skeleten.  Dresden,  1879-90. — Menzbier,  M.  von,  Vergleichende  Osteologie  der  Pinguine 
in  Anwendung  zur  Haupteintheilnng  der  Vögel  (Bull.  Soc.  Imp.  Moscöw),  1887. — Müne- Edwards, 
A.,  Eecherches  anatomiques  et  paleontologiques  pour  servir  ä  l'histoire  des  oiseaux  fossiles  de  la 
France.  Paris,  18Q7 -72.— I^ewton,  A.,  Dictionary  of  Birds.  London,  1893 -9Q.— Pycraft,  W.  1\, 
Contributions  to  the  osteology  of  Birds  (Proc.  Zool.  Soc.  London),  1898  et  seq.  [An  important  series 
of  papers  not  yet  (1901)  completed.] — Selenka,  E.,  and  Gadow,  H.,  Aves,  in  Bronn's  Classen  und 
Ordnungen  des  Thierreichs,  1869-91. — Seeley,  II.  G.,  On  the  British  fossil  Cretaceous  Birds  (Quar. 
Journ.  Geol.  Soc.  vol.  XXXIL),  1876. 


PHYLUM  VIII 


VERTEBRATA 


257 


caudal  regions,  but,  as  will  presently  be  explained,  the  sacrum  or  synsacrum 
of  birds  is  a  complex  mass  of  vertebrae  not  comparable  as  a  whole  with^the 
sacrum  of  other  vertebrates.  The  vertebrae  are  remarkable  for  their  peculiar 
saddle-shaped  articulations,  which  allow  great  freedom  of  movement.     In  the 


Fic3.  3(52. 
Hesverorriisreqalis,  Marsh.     Upper  Cretaceous  ;  Kansas.     Anterior  {A),  and  posterior  {B)  aspect  of  tl.irteenth 
cervical  vertebra,  i/i-    d,  Transverse  process  ;  /,  Costal  canal  for  vertebral  artory  ;  nc,  Neuml  canal  •  »  Pani- 
pophysis  ;  s,  Rudimentary  neural  spine  ;  z,  z',  Anterior  and  posterior  zygapopl)yses  (after  Marsh).         ' 

Mesozoic  Archaeopteryx  and  Ichthyornis  the  centra  are  slightly  amphicoelous,  as 
is  also  the  case  in  modern  embryonic  birds  and  in  some  of  the  caudal  vertebrae 
of  adults.  Opisthocoelous  vertebrae  occur  among  the  dorsals  of  penguins  and 
in  a  few  other  birds,  such  as  cormorants  and  gulls,  but  the  atlas  is  the  only 
procoelous  vertebra  in  the  backbone  of  birds. 

The  cervical  region  consists  of  from  thirteen  to  twenty-five  vertebrae,  the 
commonest  number  being  fourteen  or  fifteen.  The  centra  are  mostly  elongate 
and  freely  movable  upon  one  another, 
save  that  in  hornbills  the  atlas  and  axis 
may  unite,  and  in  a  few  other  birds,  the 
tinamous  for  example,  the  last  cervical 
may  fuse  with  the  dorsals.  The  dorsal 
vertebrae  number  from  six  to  ten,  the 
first  of  the  series  being  always  the  first 
vertebra  connected  with  the  sternum  by 
a  dorsal  and  sternal  rib.  The  dorsal 
series  includes  also  those  rib  -  bearing 
vertebrae  which  are  united  with  the 
sacrum,  and  the  number  of  free  dorsals 
is  much  less,  being  as  few  as  three  in  Petroica,  only  seven  in  the  long-bodied 
grebe,  and  eight  in  the  crested  auklet.  The  centra  of  these  vertebrae  are 
comparatively  short. 

In  water  birds  {e.g.  penguins  and  some  auks)  all  the  presacral  vertebrae 
may  be  free  though  their  motion  is  restricted,  but  usually  from  two  to  four  of 
the  dorsals  are  fused  to  stiffen  the  trunk  for  flight,  one  free  vertebra  being  lef t 
between  these  and  the  synsacrum.  The  latter  is  a  very  complex  bone,  usually 
composed  in  the  adult  of  dorsal,  lumbar,  sacral,  and  caudal  vertebrae  united 
in  one  solid  mass,  as  many  as  twenty  vertebrae  taking  part  in  its  formation. 
The  true  sacrals  are  those  two  lying  behind  the  cavity  containing  the  kidneys, 
having  transverse  processes  and  sacral  ribs,  reaching  from  their  centra  to  the 
ilia.     The  rib-like  nature  of  these  may  be  seen  in  embryos,  particularly  of  the 

VOL.  II  s 


Fio.  363. 

Hesperornis  regalis,  Marsh.  Upper  Cretaceous  ; 
Kansas.  Lateral  (A),  and  anterior  (£),  aspects  of 
dorsal  vertebra,  1/2  (after  Marsh). 


258 


AVES 


C'LA^;S  IV 


ostrich,  which  as  well  as  the  apteryx  has  three  sacrals.     The  gieater  iiumber 

of  vertebrae  in  the  synsacrum  are  united  with  the  ilia  by  diapophyses,  or 

transverse  processes  given  otf  from  the  neural  arch.     The  anchylosed  vertebrae 

behind  the  true  sacrals  are  the  urosacrals,  and  belong 

to  the  caudal  series ;  their  number  may  vary  slightly 

within  specific  limits.     The  free  caudals  in  existing  Jma 

birds  usually  number  about  six,  besides  the  terminal 

ploughshare-bone  or  pygostyle,  which  is  composed  of 

from   four   to   six   fused   vertebrae.     In  the  Jurassic 


äj  Pt 


Fig.  3(54. 


Otts  tarda,  Linn.  Recent ;  Europe.  Lateral  (A),  aud  palatal  (ß),  a.spects 
of  skull,  i/j.  als,  Alisphenoid ;  ang,  Angular ;  art,  Articular ;  bo,  Basi- 
occipital  ;  bt,  Basitemporal ;  c,  Occipital  condyle,  underneath  foraiuen 
magnuin  ;  d,  Dentary  ;  et.  Median  ethmoid  ;  fr,  Frontal ;  j,  Jugal ;  jmx,  Pre- 
niaxilla ;  l,  Lachrymal ;  mx,  Maxilla ;  N,  External  nares  ;  ol,  Exoccipital ; 
OS,  Supraoccipital ;  pa,  Parietal ;  pal,  Palatino  ;  pt,  Pterygoid  ;  q,  Quadrate  ; 
sm.  Interorbital  septum  ;  spb,  Basisphenoid  ;  sq,  Squaniosal ;  vo,  Vonier  (after 
Claus). 


Archaeopteryx  there  were  at  least  twenty  free  and  long  caudals  with  a  pair  of 
rectrices  to  each  vertebra. 

All  the  presacral  vertebrae  with  the  exception  of  the  atlas  are  usually 
costiferous,  and  ribs  may  be  present  also  on  the  anterior  two  or  three  sacrals ; 
those  of  the  cervical  region  fuse  with  the  vertebrae,  except  the  last  two  or 
three.  The  true  character  of  the  cervical  processes  thus  formed  may  be  seen 
in  embryos  and  to  particular  advantage  in  the  young  ostrich,  where  they 
remain  for  some  time  free,  as  they  did  permanently  in  Archaeopterijx.  With 
few  exceptions  the  last  cervical  rib  and  all  the  thoracic  ribs  save  the  last  one 
or  two  bear  uncinate  processes,  or  thin  fiat  blades  of  bone  directed  obliquely 
upward  and  backward  to  overlap  the  succeeding  rib.  These  processes  usually 
unite  with  the  ribs,  but  in  some  cases  (Moas  and  many  water  birds)  remain 
free.  The  screamers,  Chauna,  Palarfiedea^  are  exceptional  in  that  the  ribs  are 
devoid  of  uncinate  processes,  while  they  are  vestigial  in  the  Secretary  Bird. 
Appended  to  the  thoracic  ribs  are  sternal  or  abdominal  ribs,  from  two  to 
five  pairs  of  which  are  attached  to  the  sternum. 

A  sternum  is  always  present,  except  possibly  in  Archaeopteryx,  and  this  is 
externally  convex  and  generally  broad.  It  may  cover  only  the  anterior 
portion  of  the  thorax,  or  may  be  so  prolonged,  as  in  water  birds,  that  its 
posterior  end  underlies  the  pelvis,  or  extends  nearly  to  the  pubes,  as  in 
humming-birds.  In  birds  of  fiight  or  those  which  use  their  wings  in 
swimming,  as  the  penguins  and  auks,  the  sternum   is  keeled  beneath ;  but 


PHYLÜM  \ni 


VERTEBRATA 


259 


in  flightless  birds  (Ratites)   it  may  be  quite  smooth.     The  anterior  end  may 

or  may  not  bear  a  manubrial  process,  the  posterior  portion  may  be  pointed 

rounded,     emarginate,  ' 

or    have   two  or   four 

notches,  sometimes 

very  deep.     The  cora- 

coids  are  attached  to    JHH^^^^^^^^M^^Mt^  -.L^S^tKlM^^.  it 

the    front   portion    of 

the   sternum,  and   im- 

mediatelybehind  these 

are  two  processes,  one 

on  either  side,  known  ^ 

as  the  costal  processes, 

to  which  some  of  the 

abdominal    or    sternal  y 

ribs  are  articulated. 

The5Ä;i*//(Fig.364) 
is  characterised  by  the        ,,  ,   ,.     ,         „    Fio.sm. 

,  ,      .  /      ,  Apteryx  austrahs,  Owen.     Receiit ;  New  Zealantl.     Left  lateral  aspect  of 

early      lUSlOn       Ot       itS    pelvls,  8/4.    a,  Acetabulum  ;  il,  Ilium  ;  is,  Ischiuiii ;  p,  Ilio-pectiiieal  process; 
^  ^  ^  „  -  •  4.  i      i,  P',  Pubis  (after  Marsh). 

constituent    bones, 

especially  those   forming   the   brain   case  where   the  sutures   are   completely 

obliterated    in   the    adult.     In   the   tinamous,   however,   the  suture    between 
ij,  the   parietals  and   frontals   seems   to   remain   permanently 

open.  The  brain  cavity  is  relatively  less  diminutive  than 
in  reptiles,  exceeding  even  that  of  Pterosaurs  by  a  con- 
siderable  margin.  The  cranial  osteology  is  very  similar  to 
that  of  the  Archosauria,  the  chief  difference  consisting  in 
the  constant  absence  of  an  upper,  and  constant  presence  of 
a  lower  temporal  arcade.  The  large  orbits  look  forward 
in  the  owls,  but  are  laterally  directed  in  the  majority  of 
birds,  and  except  in  parrots  are  incompletely  enclosed  on 
the  inferior  margin.  A  sclerotic  ring  of  numerous  bony 
pieces  is  very  generally  developed  around  the  eye.  An 
antorbital  vacuity  is  present,  as  in  Dinosaurs,  Pterosaurs, 
and  Crocodilians,  close  in  front  of  which,  near  the  base  of 
the  beak,  are  placed  the  paired  external  narial  openings. 

The  Single  occipital  condyle,  formed  mainly  by  the 
basioccipital,  is  shifted  downwards  and  forwards  so  that 
the  long  axis  of  the  head  is  approximately  at  right  angles 
to  that  of  the  neck.  The  paired  parietals  are  exceeded  in 
size  by  the  large  frontals,  which  form  the  greater  part  of 
the  cranial  roof  and  superior  border  of  the  orbits.  Inde- 
pendent  postorbitals  and  postfrontals  are  not  developed, 
and  there  is,  of  course,  no  supratemporal  vacuity.  The 
inferior  temporal  arcade,  formed  by  the  slender  jugal  and 

i.in...   Anterior  (^X  and  quadrato-iugal,  couuccts   the  equallv  slender  maxilla  with 

proximal  (/>'),  aspect  of    ^  J    ö     J  i  ./ 

tarsometatarsusofyoung    the  Quadrate. 

ludividuai.  rj^j^g  squamosal  and  periotic  Clements  (proötic,  epiotic, 

and  opisthotic)  fuse  to  form  a  single  bone  which  is  united  with  the  occipital  and 
[)arietals,  and  to  which  the  large  quadrate  is  movably  attached.     An  independent 


Fig. 

Meleagris 


galliparo. 


260  AVES  CLASS  iv 

lachrymal  is  often  present  at  the  anterior  margin  of  the  orbit,  and  there  is  an 
ossified  or  membranous  interorbital  septum  of  considerable  size.  In  the  anterior 
Prolongation  of  the  latter  is  a  vertically  placed  unpaired  ethmoid,  which  is 
continued  in  front  as  a  bony  or  cartilaginous  nasal  septum.  The  lateral 
ethmoids  are  placed  between  the  orbits  and  external  nares,  and  are  pierced 
for  the  passage  of  the  olfactory  nerves.  The  greater  part  of  the  beak  is 
formed  by  the  fused  premaxillae,  with  the  sides  of  which  the  maxillae  are 
fused ;  its  margins  are  sheathed  with  a  horny  layer,  and  it  is  often  movably 
connected  with  the  skull.  When  the  mouth  is  opened,  the  end  of  the  beak  is 
raised  by-  pressure  transmitted  to  it  from  the  quadrate  by  means  of  the  ptery- 
goid  and  palatine  bones,  and  more  especially  by  the  rod-like  quadrato-jugal. 

Broadly  speaking,  the  bones  of  the  palatal  portion  of  the  skull  are  arranged 
on  two  plans.  In  the  one  the  vomer  is  broad  and  unites  in  front  with  the 
maxillo-palatines,  while  behind  it  receives  the  posterior  extremities  of  the 
palatines  and  the  anterior  ends  of  the  pterygoids,  which  are  thus  excluded 
from  contact  with  the  sphenoidal  rostrum.  This  is  the  dromaeognathous  type 
of  palate  found  in  struthious  birds,  the  apteryges  and  tinamous.  In  birds 
with  this  arrangement  the  head  of  the  quadrate  usually  has  but  a  single 
articular  face,  or  is  but  faintly  divided  into  two  portions ;  and  rather  long 
basipterygoid  processes  from  the  sides  of  the  sphenoid  give  this  bone  some- 
what  of  a  cruciform  shape. 

In  the  second  type  of  palate,  which  may  be  called  the  euornithic,  the  vomer 
embraces  posteriorly  the  sphenoidal  rostrum  between  the  palatines,  and  these 
latter  articulate  with  the  pterygoids  and  with  the  sphenoid.  This  arrange- 
ment predominates  in  the  vast  majority  of  birds,  and  they  also  have  the  head 
of  the  quadrate  double,  or  with  two  articular  facettes.  Basipterygoid  processes 
are  present  in  some  euornithic  skulls,  but  these  most  frequently  assume  the 
form  of  low  facettes  on  the  sphenoidal  rostrum,  with  which  the  pterygoids  are 
movably  articulated.  The  euornithic  type  of  skull  is  subject  to  various 
modifications  in  the  development  of  the  vomer  and  those  inwardly  directed 
processes  of  the  maxillae  termed  the  maxillo-palatines.  When  the  vomer  is 
pointed  in  front  and  entirely  free  from  the  maxillo-palatines,  and  these  are 
free  from  each  other,  the  skull  is  termed  schizognathous ;  when  the  maxillo- 
palatines  are  expanded  and  fused  with  each  other,  the  vomer  being  small 
or  absent,  the  skull  is  desmognathous ;  when  the  vomer  is  expanded  in  front 
and  free  from  the  maxillo-palatines,  and  these  are  slender  at  their  point  of 
origin  and  disjoined,  the  skull  is  said  to  be  aegithognathous. 

Two  terms  applied  to  conditions  of  the  bones  bounding  the  narial  openings 
and  much  used  in  Classification,  holorhinal  and  schizorJiinal,  may  be  explained 
here.  In  the  holorhinal  type  the  openings  are  more  or  less  oval,  the  posterior 
border  curved  and  lying  in  advance  of  the  posterior  ends  of  the  premaxillaries. 
In  the  schizorhinal  type  the  openings  are  more  or  less  elongate  with  the 
posterior  border  angular  or  slit-like  and  lying  back  of  the  posterior  ends  of 
the  premaxillaries. 

In  all  modern  birds  the  mandibular  rami  become  fused  at  an  early  stage 
into  a  long  Symphysis,  and  only  among  certain  Mesozoic  forms  {Ichthjornü) 
are  they  united  by  suture  or  by  ligaments  as  in  reptiles.  The  six  elements 
of  which  the  mandible  is  composed  fuse  into  a  single  piece  as  in  modern  birds, 
and  there  is  frequently  a  lateral  vacuity  between  the  dentary  and  splenial,  as 
in   crocodiles.     Although    the   earliest   known   birds   have   conical  thecodont 


PHYLUM  VIII  VERTEBRATA  261 

teeth,  and  dental  papillae  or  a  dental  ridge  sometimes  occur  in  the  jaws  of 
some  modern  embryos  (parrot,  ostrich),  trne  teeth  are  invariably  wanting 
among  existing  species. 

The  pedoral  arch  is  firmly  attached  to  the  thorax,  in  conformity  with  the 
mechanical  requirements  of  flight.  The  long  blade-like  scapula  has  no  ridge, 
extends  along  the  dorsal  side  of  the  thoracic  ribs,  and  takes  part  with  the 
coracoid  in  the  glenoid  cavity  for  the  head  of  the  humerus.  Penguins  are 
exceptional  in  having  the  scapula  broadly  expanded  posteriorly.  The  coracoids 
are  stout  and  pillar-like,  their  function  being  to  receive  the  downward  pull  of 
the  wing  muscles  during  flight.  The  clavicles,  which  are  usually  united  in  a 
forked  bone  (furcula),  sometimes  act  as  supports ;  and  by  their  union  with 
the  coracoids  afc  the  shoulder-joint,  and  with  the  sternal  keel  below  in  the 
centre,  tend  to  resist  the  thrust  of  the  wing  muscles  in  flight.  In  some  birds 
of  powerful  flight  (pigeons,  humming-birds),  however,  the  clavicles  are  so  weak 
as  to  be  of  no  service  from  a  mechanical  standpoint.  Among  Ratites  and  also 
a  fevv  Carinates  (toucans,  parrots)  the  clavicles  are  rudimentary  or  wanting, 
and  never  unite  to  form  a  furcula.  The  furcula  of  Carinates  may  anchylose 
either  with  the  keel  of  the  sternum  {Steganopodes)  or  with  the  coracoids  {Opis- 
fhocomiis),  and  in  the  frigate  birds  with  both  at  once. 

The  humerus  of  Carinates  is  expanded  at  both  ends,  and  provided  at  its 
proximal  extremity  with  a  strong  pre-axial  delto-pectoral  ridge  for  the  attach- 
ment of  the  pectoral  muscles.  Its  articular  head  is  vertically  elongated,  and 
there  is  often  a  pneumatic  foramen  adjoining  it  on  the  inner  side.  At  its 
distal  extremity  is  a  prominent  oblique  condyle  on  the  inner  side  of  the  palmar 
aspect  for  articulation  with  the  radius,  but  there  are  never  any  condylar 
foramina.  The  humerus  of  flightless  birds  is  degenerate,  and  sometimes  absent 
altogether,  as  in  many  Moas.  In  the  fore-wing,  which  is  generally  longer 
than  the  humerus,  the  ulna  is  more  strongly  developed  than  the  radius,  and 
often  exhibits  a  row  of  tubercles  along  its  lower  edge  for  the  attachment  of 
the  secondaries.  The  carpus  of  adult  modern  birds  contains  only  two  bones 
(radiale  and  ulnare) ;  a  distal  row,  however,  is  indicated  in  embryos  by  two 
separate  cartilaginous  elements,  which  later  become  fused  with  the  metacarpals. 
The  latter  are  never  more  than  three  in  number,  are  unequally  developed,  and 
in  existing  Carinates  are  more  or  less  completely  fused.  Metacarpal  No.  l  is 
much  reduced,  and  bears  one  or  more,  rarely  two,  short  phalanges  for  the 
Support  of  the  so-called  bastard  wing  (alula) ;  the  second  metacarpal  usually 
bears  two  phalanges  and  the  third,  one.  The  first  and  second  digits  are  some- 
times clawed  (Struthio,  Bhea,  Chauna),  and  in  Arcliaeoptertjx  all  three  terminate 
in  claws. 

The  three  elements  of  the  pelvis  are  anchylosed  (except  in  Archaeopteryx), 
and  usually  unite  with  the  synsacrum.  In  water-birds  this  union  takes  place 
somewhat  slowly,  and  in  penguins  and  the  great  auk  not  at  all.  The  ilium 
is  elongate,  and  may,  as  in  birds  of  prey,  extend  much  further  in  front  of  the 
acetabulum  than  behind  it.  Ischium  and  pubis  are  both  directed  backwards. 
The  pubes  often  remain  free  from  the  ilia,  and  never  unite  with  one  another 
to  form  a  Symphysis  except  in  the  ostrich.  Since  the  retroversion  of  the  pubis 
is  proved  by  embryological  researches  to  be  a  secondary  modification,  no 
homology  can  exist  between  this  and  the  post-pubis  of  Ornithopodous  Dino- 
saurs,  and  the  processus  iliopeäinealis  (Fig.  365)  must  be  regarded  as  a  structure 
peculiar  to  birds  alone. 


262  AYES  CLASS  iv 

The  femur  in  birds  is  short  and  stout,  with  the  neck  and  head  extending 
inwards  into  the  acetabulvim  at  right  angles  to  the  shaft.  The  latter  is 
directed  forwards  and  slightly  downwards  during  life,  and  is  concealed  beneath 
the  flesh  and  feathers  of  the  abdomen  in  such  a  way  that  the  knee-joint  is  not 
visible  externally.  Its  distal  condyles  are  large  and  antero  -  posteriorly 
elongated,  and  a  patella  is  present  in  most  cases.  The  tibia  is  a  stout  bone 
considerably  longer  than  the  femur.  Its  expanded  proximal  end  exhibits  a 
procnemial  crest,  which  may  extend  above  the  knee-joint,  and  the  distal 
extremity  has  a  trochlea-like  surface,  transversely  elongated,  and  slightly 
hollowedjn  the  middle.  In  young  Ratites,  and  in  the  embryos  of  Carinate 
birds,  the  presence  of  a  suture  near  the  distal  end  of  this  bone  indicates  that 
an  astragalus  and  calcaneum  are  fused  with  it,  thus  forming  a  tibio-tarsus. 
In  the  Moas  the  united  astragalus  and  calcaneum  remain  for  some  time  quite 
free  from  the  tibia. 

The  fibula  in  birds  is  a  degenerate  bone,  and  best  developed  in  the  Moas, 
where,  although  short,  it  is  stout  and  free.  In  most  birds  it  is  more  or  less 
fused  with  the  tibia,  and  is  longest  in  the  penguins,  the  fish-hawk,  and  some 
owls,  where  it  reaches  almost  to  the  ankle-joint. 

The  distal  row  of  tarsals  fuses  with  the  coössified  metatarsals  to  form  a 
tarso-metatarsus  (Fig.  366).  This  bone  is  peculiarly  characteristic  of  birds, 
and  its  variations,  together  with  those  of  the  tibia,  cause  the  difFerences  in  the 
length  of  the  leg  among  difFerent  forms,  which  are  sometimes  enormous.  The 
fifth  metatarsal  is  never  developed,  and  the  first,  when  present,  is  always 
rudimentary,  being  attached  to  thfe  inner  side  of  the  tarso-metatarsus  by 
ligament,  or  more  rarely  by  suture.  Metatarsals  Nos.  ll  to  IV  are  imper- 
fectly  united  in  Archaeopteryx,  and  completely  separated  in  the  embryos  of 
modern  birds  ;  but  in  the  adult  condition  they  are  always  fused.  into  a  single 
bone,  although  the  three  components  are  plainly  distinguishable  in  penguins. 
This  metapodal  dement  terminates  distally  in  three  pulley-like  surfaces  for 
the  articulation  of  the  phalangeals.  Generally  the  median  condyle  is  thrust 
forward  in  advance  of  the  other  two,  and  the  modifications  of  this  region 
afFord  important  taxonomic  characters.  There  is  remarkable  constancy  in  the 
number  of  phalanges  present  in  the  toes  of  birds,  the  formula  being  2,  3,  4,  5 
in  almost  all  cases  where  the  füll  complement  of  digits  is  present.  The 
hallux,  however,  is  frequently  wanting,  and  in  the  ostrich  only  digits  Nos.  lil 
and  IV  are  developed.  An  apparent  exception  to  the  usual  formula  occurs 
among  some  swifts  and  goatsuckers,  where  owing  to  fusion  of  some  of  the 
phalanges  the  formula  is  2,  3,  3,  3. 

Fossil  egg-shells  or  casts  of  the  same  have  been  obtained  from  the  Cretace- 
ous  and  various  Tertiary  horizons,  but  are  naturally  much  less  common  than 
bones  of  the  skeleton.  They  belong  for  the  most  part  to  cursorial  or  wading 
birds.  The  largest  known  eggs  are  those  of  Aepyornis,  from  the  superficial 
deposits  of  Madagascar,  which  have  a  capacity  of  about  eight  liters.  Foetal 
bones  are  occasionally  found  in  Moa  eggs  from  New  Zealand.  Certain  three- 
toed  footprints  occurring  in  the  Trias  of  the  Connecticut  Valley  were  formerly 
ascribed  to  an  avian  origin,  but  are  doubtless  referable  for  the  most  part  to 
bipedal  Dinosaurs.  The  presumable  kinship  between  birds  and  Dinosaurs  has 
already  been  discussed  under  the  head  of  the  latter  group 

In  comparison  to  the  large  number  of  recent  species,  of  which  over  12,000 
have  been   described,  the  400  or  500  known   fossil   forms   yield   but   an   in- 


PHYLUM  VIII  VERTEBRATA  263 

significant  record  of  the  ancient  avian  faunas.  Yet  as  far  as  the  record  shows, 
Tertiary  ornithic  faunas  were  essentially  like  the  modern,  and  it  is  only  as  we 
direct  attention  to  the  Mesozoic  that  signal  difierences  are  to  be  observed.  In 
Archaeopteryx,  the  oldest  known  bird,  the  tail  had  not  become  atrophied,  nor 
the  teeth  lost  in  the  adult ;  the  pelvis  was  not  fully  developed,  and  the  verte- 
brae  had  not  yet  acquired  the  saddle-shaped  articulations  characteristic  of 
post-Jurassic  forms. 

The  Classification  of  Birds. — Classification,  as  here  employed,  is  an  attempt  to 
place  together  related  species  and  to  arrange  the  groups  thus  formed  so  as  to 
indicate  the  extent  to  which  each  has  been  modified,  or  has  departed  from 
what  is  conceived  to  be  the  most  generalised  or  lowest  type.  Further  than 
this  a  linear  or  tabular  arrangement  cannot  go,  and  it  is  obviously  impossible 
to  express  in  such  a  manner  the  interrelationships  of  the  various  groups ; 
moreover,  such  a  series  cannot  be  so  arranged  that  we  may  pass  by  regulär 
gradations  from  the  lower  to  the  higher  forms. 

The  difficulties  attending  the  Classification  of  birds  are  at  once  their  great 
general  similarity  of  structure  and  their  numerous  adaptive  modifications, 
sometimes  slight,  sometimes  so  great  as  to  obscure  characters  of  real  value. 
There  are,  besides,  a  certain  number  of  aberrant  forms  whose  exact  position  is 
a  matter  of  uncertainty,  and  others  in  which  there  are  departures  more  or  less 
pronounced  from  the  general  structure  of  the  group  in  which  they  should 
obviously  be  placed.  For  it  must  be  constantly  borne  in  mind  that  in 
palaeornithology  we  are  not  dealing  with  the  entire  class  of  birds,  but  only 
with  a  certain  portion  of  it,  since  the  number  of  known  fossil  birds  is  very 
small,  and  it  is  consequently  impossible  to  trace  the  lines  of  descent  of  existing 
species ;  we  do  not  even  have  broken  lines  to  guide  us,  but  merely  isolated 
dots  to  indicate  their  probable  existence.  For  the  proportion  of  fossil  to 
existing  birds  is  small  indeed,  about  500  extinct  to  12,000  living  species,  and 
most  of  these  are  from  the  Miocene  or  later  horizons ;  they  are  easily  refer- 
able  to  existing  families  and  often  to  existing  genera,  so  that  they  throw  little 
light  on  the  phylogeny  of  modern  birds. 

The  reasons  for  the  remarkable  dearth  of  fossil  avian  remains  are  obscure, 
and  those  usually  adduced,  such  as  the  imperfection  of  the  geological  record,  do 
not  seem  altogether  satisfactory,  the  more  so  since  in  some  favoured  localities, 
such  as  Allier  in  Southern  France,  and  Fossil  Lake,  Oregon,  bones  of  birds 
have  been  found  in  considerable  numbers.  The  palaeontologist  is  further 
hampered  by  having  to  restrict  himself  to  characters  offered  by  the  skeleton 
alone;,  and  while  these  are  of  primary  importance,  much  valuable  evidence 
may  be  gathered  from  the  muscles,  viscera,  and  plumation.  And  birds  must 
be  classified  by  the  resultant  of  all  their  characters,  not  by  any  one  set,  for 
the  exceptions  to  any  general  rule  are  nowhere  more  numerous  among  verte- 
brates  than  in  this  particular  class.  Finally,  there  is  the  personal  equation, 
or  the  individual  opinion  of  the  classifier,  as  to  the  relative  values  of  the 
characters  on  which  we  must  rely  for  uniting  or  separating  species.  For  these 
reasons  no  two  Systems  will  be  found  to  agree  in  all  their  details,  certain 
birds  or  groups  of  birds  being  particularly  liable  to  shifting  about  at  the  hands 
of  the  taxonomist. 

The  divisions  here  employed  are  practically  those  of  Stejneger,^  although 

^  Standard  Natural  History,  vol.  TU.— Birds.  Boston,  1885  (afterwards  changed  to  the  Riverside 
Natural  History). 


264 


AVES 


CLASS  IV 


the  Hespei'ornithes,  Ichthyornithes,  and  Impinmes  have  been  reduced  to  a  lower 
grade  than  that  assigned  them  in  his  System,  as  has  been  done  by  Fürbringer 
and  others.  These  divisions,  Avhich  correspond  in  a  great  measure  to  the  sub- 
orders  of  Fürbringer,  are  larger  than  those  usually  considered  as  Orders,  and 

often  comprise  some  very 
diverse  forms.  An  alterna- 
tive is  to  treat  each  group 
separately,  which  gives  from 
twenty  to  forty  divisions, 
variously  designated  as 
f amilies,  sub-orders,  or  Orders. 


Sub-Class  1. 
SAURURAE.^ 

Tau  feathers  arranged  in 
pairs  on  either  side  of  the  elon- 
nate  caudal  vertebrae.  Sternum 
rudimentary  ;  dorsal  rihs  with- 
out  imcinate  processes ;  cervical 
rihs  free;  vertebrae  amphicoelous. 
Pelvic  elements  separate,  as  are 
also  the  metacarpals ;  digits 
clawed. 


Order  1. 
ARCHAEORNITHBS. 

Skull  typically  bird  -  like, 
provided  with  a  series  of  conical, 
socJceted  teeth  along  the  margin 
of  the  Upper  and  lower  jaws. 
Vertebrae  amphicoelous,  and  the 
lizard-like  tail  long  er  than  the 
presacral  portion  of  the  column. 
Remiges  and  redrices,  tvifh  their 
coverts,  well  developed.  Upper 
Jura. 

Archaeopteryx,  von  Meyer 
(Gryphosawus,  Wagner),  (Fig. 
367).  This  unique  and  in 
many  respects  remarkable  genus  is  known  by  two  nearly  complete  skeletons 
from  the  Lithographie  Stone  of  Bavaria,   one  of  which  is  preserved  in  the 

^  Dames,  W.,  Ueber  Archaeopteryx  (Palaeont.  Abhandl.  Danies  und  Kayser,  vol.  11.  j).  119), 
■  1884. — Ueber  Brustbein,  Schulter-  und  Beckengürtel  der  Archaeopteryx  (Sitzungsber.  preuss.  Akad. 
Wissensch.  vol.  XXXVIII.  p.  818),  1897.— Oweri,  R.,  On  the  Archaeopteryx  of  von  Meyer  (Phil. 
Traus.  vol.  CLIII.  p.  33),  im'd.—Pycraft,  W.  P.,  The  Wing  of  Archaeopteryx  (Nat.  Sei.  vol.  VIII. 
p.  261),  1896.— Seeley,  H.  G.,  Professor  C.  Vogt  on  Archaeopteryx  (Geol.  Mag.  [2],  vol.  VIII.  p.  454), 
18Sl.~Vogt,  C,  Sur  l'Archaeopteryx  macrura  (Revue  Scient.  [2],  vol.  XXIII.  p.  241),  187i\ 


Fig.  367. 


Archaeopteryx  lithographica,  v.  Meyer.  Lithographie  Stone; 
Eichstädt,  Bavaria.  '■^'/■/.  c,  Carpal ;  cl,  Fnrcula  ;  co,  Coracoid  ;  h, 
Humerus  ;  r,  Radius ;  sc,  Öcapula ;  u,  Uhia.  Original  in  Berlin 
^luseum  (from  Steinniann  and  Döderlein). 


SUB-CLASS II  ORNITHURAE  265 

British  and  the  other  in  the  Berlin  Museum.  They  are  considered  as  repre- 
senting  two  species,  A.  macrura  and  A.  siemensi,  and  fortunately  Supplement 
each  other  in  such  wise  that  the  osteology  is  known  with  tolerable  accuracv. 
Contrary  to  the  usual  condition  among  birds,  none  of  the  bones  appear  to 
have  been  pneumatic. 

The  skull  is  shaped  like  that  of  a  typical  bird,  its  constituent  elements 
being  fused  together,  and  the  quadrate  apparently  free.  A  sclerotic  ring  is 
present,  and  there  is  a  series  of  thirteen  conical  teeth  on  each  side  in  the  upper 
jaw,  fixed  probably  in  distinct  sockets.  The  vertebral  column  comprises 
about  fifty  vertebrae,  of  which  ten  or  eleven  are  cervical,  eleven  or  twelve 
dorsal,  two  lumbar,  six  or  seven  sacral,  and  about  twenty  caudal.  The 
cervical  and  dorsal  vertebrae  seem  to  have  been  amphicoelous,  or  amphi- 
platyan,  as  in  reptiles,  and  bear  weakly  developed  transverse  processes  and 
neural  spines.  The  ribs  are  very  slender,  free  in  the  neck  region,  and  without 
ossified  uncinate  processes  in  the  thoracic  region.  Twelve  or  thirteen  pairs  of 
a,bdominal  ribs  are  present  in  the  ventral  wall  of  the  body  cavity.  In  the 
pectoral  arch  the  long  and  slender  scapula  is  essentially  bird-like,  and  exhibits 
a  well-developed  acromion.  The  sternum  is  unfortunately  not  well  preserved, 
but  the  coracoids  and  U-shaped  furcula  resemble  those  of  modern  Carinate 
birds.  The  wing  is  relatively  small,  and  its  bones  slender.  Eadius  and  ulna 
are  straight,  and  but  little  shorter  than  the  humerus.  The  carpus  is  im- 
perfectly  known,  and  the  three  metacarpals  appear  to  have  been  free.  Meta- 
carpal  No.  l  is  quite  short,  and  No.  ll  longer  and  stouter  than  the  first  or 
third.  The  lizard-like  manus  terminates  in  three  clawed  digits  having  the 
phalangeal  formula  2,  3,  4. 

The  three  pelvic  elements  appear  to  have  been  distinct,  and  united  with 
each  other  by  persistent  sutures.  The  acetabulum  is  perforate.  The  bind 
limb  is  essentially  avian,  and  conspicuous  only  for  the  weak  development  of 
the  cnemial  crest  of  the  tibia.  There  are  four  clawed  digits  in  the  pes  (Nos.  l 
to  iv),  with  the  phalangeal  formula  2,  3,  4,  5.  In  the  wing  are  observed 
seven  primary  and  ten  secondary  remiges  with  their  coverts.  The  rectrices  of 
the  tail  are  arranged  in  pairs,  directed  obliquely  back  ward,  one  pair  to  each 
vertebra.  Contour  feathers  are  also  indicated  on  the  neck  and  along  the 
tibia. 

Archaeopteryx  appears  to  have  been  intermediate  in  size  between  an  ordinary 
pigeon  and  crow,  and  to  have  enjoyed  a  moderate  power  of  flight.  The  clawed 
digits  of  the  manus  were  doubtless  effective  in  climbing  trees  and  rocks.  In 
this  connection  the  quadrupedal  habits  of  young  modern  birds,  especially  the 
hoactzin  (Opisthocomus),  cormorant,  and  certain  water-fowls,  are  of  significance 
as  indicating  a  possible  survival,  "  handed  down  from  the  very  dawn  of  avian 
development "  (Pycraft). 


Sub-Class  2.     ORNITHURAE. 

Tail  feathers  arranged  like  a  fan  around  the  terminal  portion  of  the  shorfened 
caudal  vertebrae,  a  number  of  which  are  umally  united  to  form  a  pygostyle.  Sternum 
well  developed;  dorsal  [ribs  (save  in  Palamedea  and  Chauna)  tvith  uncinate 
processes;  cervical  ribs  united  with  their  vertebrae.  Pelvic  elements  proximally 
united  ;  metacarpals  united. 


266 


AYE& 


1 


CLASS IV 


Super-Order  1.     ODONTOLCAE.' 

Birds  with  teeth  implanted  in  a  continuous  groove  ;  mandibular  rami  united  at 
the  Symphysis  hy  ligament  only,  and  with  their  component  hones  free  jrom  one  another. 
Clavides  free  from  one  another.  Basipterygoid  processes  wanting;  palatal  struäure 
imperfedly  known,  but  the  head  of  the  quadrafe  is  single  and  the  vomer  is  probably 
paired.     Bones  of  pelvis  free  posteriorly  ;  vertebral  articidations  saddle-shaped. 

The  Order  Hesperornithes  contains  members  of  the  genus  Hesperornis  (Figs. 
362,  363,  368)  and  their  allies  from  the  Upper  Cretaceous  of  Kansas.     So  far 


Fig.  368. 
Hesperornis  regalü,  Marsh.     Upper  Cretaceous  ;  Kansas.     Restoration  of  skeleton,  Vs  (alter  Marsh). 

as  is  known  the  teeth  in  the  upper  mandible  were  confined  to  the  maxilla,  for 

1  Marsh,  0.  C,  Odoutornithes  :  A  Monograph  on  the  Extinct  Toothed  Birds  of  North  America. 
Washington,  18S0.  — Will iston,  S.  TF.,  Plumage  of  Hesperornis  (Kan.  Univ.  Quart,  vol.  V.  p. 
53),  189(). 


SUPER-ORDER  II 


ODONTORMAE 


26^ 


in  Hesperornis  the  extremely  long  premaxillae  are  toothless.  In  the  mandible 
the  teeth  extend  to  the  tip.  Hesperornis  was  a  flightless  and  highly  specialised 
diving  bird  of  great  size,  having  the  wing  represented  by  the  humerus  only. 
The  coracoid  is  short  and  wide,  but  the  clavicle  articulates  with  the  inner  side 
of  the  head  as  is  customary  among  birds.^  The  pelvis  is  greatly  compressed, 
the  femora  short  and  massive,  the  patella  enormous  and  functioning  as  a 
cnemial  process,  the  tibiae  hollow.  The  outer  digit  of  the  four-toed  foot  is 
much  the  largest,  being  nearly  twice  the  length  of  the  third  digit ;  the  toes 
appear  to  have  been  lobed,  and  the  tarsi  were  directed  outwards  from  the  sides 
of  the  body  and  not  downwards  as  in  modern  birds. 

Emdiornis,  from  the  Cambridge  Greensand,  has  been  considered  as  a  related 
form,  and  another  genus,  Baptornis,  also  oceurs  in  the  Kansas  Cretaceous. 


Super-Order  2.     ODONTORMAE. 

Birds  with  teeth  in  separate  sockets  and  with  slightly  amphicoelous  vertehrae. 
Palatal  striidure  unknown,  but  the  quadrate  has  but  a  Single  head. 

The  Order  Ichthyornitlies  is  best  known  by  Ichthyornis  victor,  Marsh  (Figs. 

369-371),  a  bird  about  the  size  of  a  pigeon, 
from  the  Cretaceous  of  Kansas.  The  deeply 
keeled  sternum  and  the  humerus  indicate  a 
bird  of  powerful  flight,  but  as  in  Hesperornis 
and  most  Dromaeognathae,  thecomponentbones 
of  the  pelvis  are  posteriorly  free.  As  in 
Hesperornis,  the  teeth  of  the  separated  halves 


Fir..  370. 

Ichthyornis  dispar,  Marsli.    Upper  Cretaceous ; 
Kansas.     Mandible,  ^U  (after  Marsh). 


If 


Fio.  371. 


Fio.  369. 
Ichthyornis  victor,  Marsh.     Upper  Cretaceous;    Kansas. 
Restoi-ation  of  skeleton,  1/2  (alter  Mansh). 


Ichthyornis  dispar,  Marsh.  Lateral  (A),  and 
anterior  (/?),  aspect  of  cervical  vertebra,  2/j 
(after  Marsh). 


of  the  lower  mandible  extend   the  füll  length  of  the  dentary,  while  in  the 
Upper  jaw  they  were  confined  to  the  maxilla. 

^  This  is  quite  differeut  from  what  is  sliown  in  Professor  Marsh's  figure,  but  a  specimen  in  the 
United  States  National  Museum  shows  that  in  his  specimens  the  clavicles  were  slightly  imperfect. 
'^  Marsh,  0.  C,  Odontornithes,  etc.     Washington,  1880. 


268  AVES  CLASS  iv 


Super-Order  3.     DROMAEOGNATHAE/ 

The  skull  is  of  the  Dromaeognathous  type,  and  the  head  of  the  quadrate 
is  Single,  save  in  the  Apteryges,  in  which  the  articular  head  is  broad,  and 
almost,  or  quite,  double.  While  the  single-headed  quadrate  is  also  found  in 
the  toothed  birds  Ichthyornis  and  Hesperornis,  in  these  the  halves  of  the  lower 
mandible  are  free  from  one  another,  a  point  wherein  they  difFer  from  other 
birds.  The  ischia  are  never  united  with  the  ilia  save  at  the  extreme  distal 
portion,  and  are  usually  slender  and  free,  while  the  aspect  of  the  entire  pelvis 
is  quite  Hifferent  from  that  of  the  Euornithes.  The  upper  end  of  the  tarsus 
is  never  perforated  for  the  passage  of  tendons,  and  the  terminal  caudals  do  not 
fuse  to  form  a  pygostyle. 

The  Dromaeognathae  comprise  a  small  number  of  birds  difFering  from  one 
another  in  important  particulars,  but  all  evidently  related  to,  or  directly 
descended  from,  old  and  primitive  forms ;  they  may  be  considered  as  the 
scattered  survivors  of  the  ancient  avi-fauna  of  the  globe,  and  some  are  confined 
to  a  remarkably  small  area.  It  is  scarcely  too  much  to  say  that  greater 
differences  of  structure  are  to  be  found  among  the  few  members  of  this  division 
than  among  all  other  existing  birds,  and  these  differences  are  such  that  they 
are  frequently  placed  in  different  Orders.  The  flightless  struthious  birds  have 
a  sternum  devoid  of  a  keel,  and  very  variable  in  shape  posteriorly,  while  the 
Shoulder  girdle  exhibits  various  degrees  of  degeneration  from  the  absence  of 
cla vieles  to  the  lack  of  the  entire  wing.  The  pelvic  region  is  also  very  variable 
as  to  the  ischia  and  pubes. 


Order  1      STRUTHIONBS. 

This  Order  comprises  the  true  ostriches  (Struthio),  the  rheas  (FJiea),  the 
cassowaries,  and  emeus  (Casuarius  and  Dromaius),  these  forming  three  groups 
in  the  order  given,  which  are  sometimes  raised  to  ordinal  rank,  but  more  often 
considered  as  families,  super-families,  or  sub-orders.  The  extinct  Moas  forming 
the  family  Dinornithidae  form  a  distinct  division,  and  the  Aepyornithes  of 
Madagascar  still  another,  although  owing  to  lack  of  knowledge  of  their  palatal 
structure  these  last  cannot  be  accurately  placed. 

These  are  all  large  flightless  birds,  having,  so  far  as  known,  a  typically 
Dromaeognathous  skull  with  the  long  basipterygoid  processes  arising  from  the 
body  of  the  parasphenoid,  giving  it  something  of  a  cruciform  shape  ;  the 
nostrils  are  holorhinal.  The  sternum  is  not  keeled ;  the  scapula  and  coracoid 
are  short  and  fused  with  one  another,  and  the  wings  small.  All  these,  how- 
ever,  are  negative  characters  correlated  with  loss  of  the  power  of  flight. 

Family  1.     Struthionidae. 

In  the  Struthionidae,  or  ostriches,  the  pubes  are  united  in  a  ventral  Sym- 
physis, the  toes  reduced  to  two,  the  third  and  fourth  digits  only  being  present, 

^  PycrafU  W.  P.,  Morpliology  and  Phylogeny  of  the  Palaeognathae  [Ratitae  and  Onjiitvn)  and 
Neognathae  {Carinatae),  (Trans.  Zool.  Soc,  London,  vol.  XV.  p.  149),  1900.  This  important  paper 
contains  a  very  füll  bibliography  of  works  relating  to  the  group  here  called  Dromaeognatlwe.  Mr. 
Pycraft  shows  very  clearly  that  the  groups  Ratitae  and  Carinatae  are  artificial.  and  that  the 
Tinamous  belong  with  the  Ostriches. 


SUPER-ORDER  III  DROMAEOGNATHAE 


269 


and  the  weight  of  the  body  carried  mainly  by  the  third,  a  high  degree  of 
specialisation  due  to  modification  for  nmning.  Fossil  remains  of  these  birds 
occur  in  the  Lower  Pliocene  of  the  Siwalik  Hills  and  the  Island  of  Samos, 
while  fossil  eggs,  slightly  larger  than  those  of  the  living  ostrich,  have  been 
described  under  the  name  of  Struthiolithus,  frora  superficial  deposits  of  Southern 
Eussia  and  Northern  China.  This  would  seem  to  indicate  that  the  ränge  of 
the  group  has  been  restricted  through  the  agency  of  man. 

r  Family  2,     Bheidae. 

The  rheas  have  the  ischia  turned  inward,  so  that  they  meet  and  are  united 
beneath  the  ilia,  while  a  number  of  the  anterior  caudal  vertebrae  are  crowded 
out  and  aborted ;  they  have  three  digits  in  the  foot.  The  species  of  this 
family  are  confined  to  southern  South  America,  where  remains  referable  to 
existing  species  occur  in  Pleistocene  deposits. 

Diafri/ma,  Cope,  from  the  Eocene  of  New  Mexico,  was  assigned  to  this  group 
by  Cope,  but  it  is  very  doubtful  if  this  is  correct ;  the  affinities  of  Diatryma 
appear  to  be  rather  with  the  South  American  PJiororhacidae. 

Family  3.     Dromaiidae. 

The  emeus  from  Australia,  and  the  cassowaries  from  Northern  Australia, 
and  a  number  of  the  islands  to  the  northward,  have  no  striking  peculiarities 
of  the  pelvic  region,  and  are  three-toed.  The  bones  of  the  wing  are  very 
greatly  reduced  in  size.  Allied  to  the  emeus  is  Genyornis  from  the  Pleistocene 
of  Australia,  a  bird  of  massive  build  with  a  skull  0*3  m.  in  length.  Hypselomis 
occurs  in  the  Pliocene  of  India. 

Family  4.     Aepyornithidae.^ 

The  Aepyornithidae,  although  known  only  by  fossil  remains,  including  entire 
egg-shells,  from  Northern  Madagascar,  have  becöme  extinct  at  a  coraparatively 
recent.  epoch.  They  were  birds  of  great  size  and  massive  build,  having  a 
relatively  small  skull  and  an  unusually  short  and  broad  sternum,  with  well- 
developed  facettes  for  the  coracoids.  Foot  normally  with  four  digits,  but  the 
hallux  is  sometimes  wanting.  The  nearest  relatives  of  these  birds  are  con- 
sidered  to  be  the  cassowaries  and  emeus.  The  typical  species  is  the 
unfortunately  named  Aepyornis  maximus,  a  species  considerably  exceeded  in 
size  by  A.  titan,  which  has  a  tibia  80  cm.  in  length.  ' 

Family  5.     Dinomithidae. 

The  Dinomithidae  ^  comprise  about  twenty  or  twenty-five  species  of  birds 
popularly  known  as  Moas. 

1  Am/re2vs,  C.  W.,  Skeleton  of  Aepyornis  (Ibis,  p.  376),  1896.  Also,  Geol.  Mag.  [4],  vol.  IV. 
(1897),  p.  2il.—Bianconi,  G.  G.,  Recherches  sur  l'Epyornis  maximus  (Ann.  Sei.  Nat.  Zool.  [5],  vol. 
III.  p.  58),  ISQo.—Capellini,  G.,  Sul  primo  novo  di  Aepyornis  maximus  arrivato  in  Italia  (Mem.  Acad. 
Sei.  Ist.  Bologna  [4],  vol.  X.),  1889.— Mü)ie-Ed7mrds,  A.,  and  Grandidier,  A.,  Ann.  Sei.  Nat.  Zool. 
[5],  vol.  XII.  p.  167),  1870. 

-  For  papers  relating  to  Dinomithidae,  see  Hamilton,  A.,  Bibliography  of  Dinomithidae  (Trans. 
New  Zeal.  Inst.  XXVI.  (1893),  p.  229).  Also,  Hutfon,  F.  ir.,  New  Zeal.  Journ.  Sei.,  Nov.  1891, 
p.  Q.— Parker,  T.  J..  On  the  Cranial  Osteology,  etc.  of  Dinomithidae  (Trans.  Zool.  Soc.,  London, 
vol.  XIII.  p.  373),  1895.— Andrews,  C.  W.,  Skeleton  of  Megalapteryx  (Novit.  Zoologicae,  vol.  II. 
p.  188),  1897. 


270 


AVES 


The  wirigs  and  pectoral  arch  extremely  rudimentary  or  absent.  Beak 
short  and  slightly  deflected.  Hind  limbs  in  most  species  exceptionally 
massive.  Femur  usually  without  pneumatic  foramina.  Tibio-tarsus  with 
bony  bridge  over  the  groove  for  extensor  tendons.  Hallux  sometimes  present 
in  addition  to  the  three  usual  digits. 

The  "  Moas "  are  birds  of  large  or  gigantic  size,  and  of  exceptionally 
massive  build,  which  existed  in  New  Zealand  in  great  abundance  and  variety 

_  during  the  late  Tertiary,  and  became 
extinct  only  in  comparatively  modern 
times.  Their  charred  bones  and  egg- 
shells  occur  in  the  refuse  heaps  of  the 
Maoris,  and  large  numbers  of  bones  or 
occasionally  complete  skeletons  have 
been  found,  especially  in  swamps.  A 
few    specimens     have    been     found    in 


Palapte7-yx  elephantopus,  Owen  sp. 


Fio.  372. 
Pleistocene  ;  New  Zealand. 


1/18  (after  Owen). 


caves  with  some  of  the  ligaments  and  portions  of  the  integument  preserved. 
No  remains  are  known  older  than  the  Pliocene.  The  plumage,  so  far  as 
known,  resembles  that  of  emeus  and  cassowaries. 

Dinornis,  Owen.  Beak  relatively  wide  and  pointed,  temporal  fossae  large. 
About  twenty  vertebrae  present  in  cervical  and  sacral  regions  respectively. 
Sternum  about  as  long  as  broad,  very  convex,  with  small  coracoidal 
facettes,  three  costal  facettes  on  each  side,  widely  divergent  lateral  processes, 
and  a  xiphi-sternal  notch.  Scapulo-coracoid  element  without  glenoid  cavity 
for  the  humerus.      Pelvis  narrow,  with  elevated  ilium.     Femur  comparatively 


SUPER-ORDER  IV  EUOKNITHES  271 

long,  its  medullary  cavity  with  very  thick  walls.  Tibio-tarsus  and  tarso- 
metatarsus  also  long  and  slender ;  hallux  rudimentary  or  absent.  D.  maximis, 
Owen,  attained  a  height  of  over  3*5  m.  when  standing. 

Falapteryx,  Owen  (Eurapteryx,  Haast),  (Fig.  372).  Smaller  bat  much 
stouter  than  the  preceding.  Beak  short  and  rounded ;  sternum  flat,  broader 
than  long,  without  coracoidal  facettes  ;  pelvis  low  and  broad.  Hind  limbs 
extremely  massive,  crus  relatively  short ;  hallux  present.  Total  height  less 
than  2  m. 

Anomalopteryx,  Reich.  Small  birds  of  comparatively  slender  build.  Skull 
narrow  and  elevated,  with  sharply-pointed  beak.  Sternum  much  longer  than 
broad,  moderately  flattened,  with  faint  or  no  coracoidal  facettes,  three  costal 
facettes  on  each  side,  and  a  pair  of  long  and  slender  lateral  processes.  Tarso- 
metatarsus  shorter  than  the  femur,  and  scarcely  half  as  long  as  the  tibio- 
tarsus  ;  hallux  present. 

Megalapteryx,  Mesopteryx,  Haast.  These  genera  accompany  the  preceding, 
but  are  less  satisfactorily  known. 

Order  2.     APTBRYGES.i 

This  Order  contains  the  small,  fiightless  birds  of  the  genus  Apteryx,  found 
only  in  New  Zealand.  They  are  readily  distinguished  by  their  long,  rather 
slender  beaks,  and  by  the  nostrils  opening  at  the  end  of  the  beak,  a  point 
wherein  they  differ  from  all  other  birds.  The  sternum  is  broad,  the  wings 
minute,  the  foot  four-toed,  the  first  digit  being  small,  and  above  the  level  of 
the  others.  Remains  of  several  species  of  Apteryx,  mainly  ascribable  to  living 
species,  occur  in  superficial  deposits  of  New  Zealand. 

Order  3.     CRYPTURI. 

The  tinamous,  constituting  the  order  Crypturi,  are  Dronmeognathae,  having  a 
long,  narrow  keeled  sternum,  with  a  long,  slender  lateral  process  on  either 
side.  In  the  shortening  of  the  vomer,  and  moving  forward  of  the  palatine 
region,  they  show  an  approach  towards  the  Euornithes.  The  tinamous  resemble 
little  ostriches  in  their  appearance,  but  have  a  limited  power  of  flight ;  and 
because  of  this,  their  small  size,  and  keeled  sternum,  they  have  been  kept  near 
the  gallinaceous  birds.  It  may  well  be  that  they  retain  the  primitive  characters 
of  the  group  from  which  some  of  the  Gallinae  have  been  derived,  but  it  is  of 
interest  to  note  that  while  in  some  details  of  their  musculature  they  resemble 
the  fowls,  in  other  and  more  striking  points  they  resemble  the  ostriches.  The 
group  is  eminently  characteristic  of  South  America,  although  it  extends  north- 
wards  into  Mexico.  So  far  very  few  fossil  remains  of  the  tinamous  have  been 
found,  and  these  from  comparatively  recent  deposits. 


Super-Order  4.     EUORNITHES. 

The  super-order  Euornithes  comprises  the  vast  majority  of  existing  birds, 
and  is  the  equivalent  of  the  Carinatae,  less  Ichthyornis,  and  the  tinamous.  Its 
members  are  characterised  by  having  the  Euornithic  type  of  skull  (see  p.  260), 

^  Parker,  T.  J.,  Anatomy  an-l  Development  of  Apteryx  (Pliil.  Trans.  Roy.  Soc.),  London,  1891. 


272  AVES  CLAS8IV 

and  the  ilium  and  ischium  are  always  fused  posteriorly.  The  hypotarsus  has 
oiie  or  more  tendinal  canals,  and  the  sternum  is  generally  keeled,  although  this 
is  a  character  of  little  value,  since  any  group  may  have  its  flightless  forms. 
Thus  we  have  the  owl  parrot  (Stringops  habroptilus),  Harris's  cormorant  {Halieus 
harrisi),  the  weka  rail  {Ocydromus  australis),  and  the  dodo  (Didus  ineptus), 
each  representing  a  difterent  order. 

Limits  of  space  preclude  more  than  a  brief  survey  of  the  various  sub- 
divisions  of  the  Euornithes,  and  the  student  will  no  doubt  be  Struck  by  the 
slight  and  often  unsatisfactory  nature  of  the  osteological  characters  used  to 
define  them.  It  is  hoped  that  failure  in  this  respect  may  be  pardoned,  since 
Huxley,  Fürbringer,  and  Beddard  were  all  forced  to  rely  largely  on  the  muscles 
and  pterylosis  to  define  their  divisions  of  birds. 


Order  1.     IMPENNBS.     Penguins.i 

The  penguins  deserve  particular  notice  on  account  of  their  high  specialisa- 
tion  as  swimming  birds,  while  at  the  same  time  they  present  some  primitive 
characters.  The  wings  are  shortened,  fiattened,  and  modified  into  paddles,  but 
as  they  are  moved  by  the  muscles  employed  by  other  birds  in  flight,  the 
sternum  retains  its  keel.  The  skull  is  schizognathous,  and  the  component 
bones  remain  free  from  one  another  for  an  unusual  length  of  time ;  the 
pterygoids  are  very  large.  The  scapula  is  unique  among  birds  in  being 
expanded  posteriorly.  The  dorsal  vertebrae  are  markedly  opisthocoelous. 
The  tarsus  is  short  and  wide,  and  its  three  component  tarsals  plainly  indicated 
by  their  imperfect  fusion. 

On  account  of  these  characters  and  peculiarities  found  in  the  pterylosis 
and  muscles,  Gill,  Stejneger,  and  Menzbier  have  considered  the  penguins  as 
forming  a  group  equal  in  value  to  the  rest  of  the  Euornithes ;  but  this  seems 
too  exalted  a  rank,  and  does  not  take  purely  adaptive  features  sufficiently  into 
account.  The  group  is  characteristic  of  the  southern  parts  of  the  southern 
hemisphere,  but  extends  to  the  equator  ofF  the  west  coast  of  South  America. 
Its  geological  histor}^  is  imperfectly  known,  but  the  penguins  must  have 
attain ed  their  specialisation  at  an  early  date,  as  one  genus  (Palaeospheniscns) 
has  been  obtained  from  the  Eocene  of  Patagonia,  and  a  giant  form  (Palce- 
eudyptes)  is  known  from  the  Eocene  of  New  Zealand. 


Order  2.     CBCOMORPHAE. 

The  Cecoinorphae  include  the  auks,  gulls,  divers,  and  petrels,  these  last 
diverging  from  the  other  members  of  the  order  and  often  placed  in  an  order 
by  themselves,  the  Tubinares.  The  divers  {Colymbidae)  and  petrels  are  con- 
sidered, among  existing  birds,  to  be  those  nearest  the  penguins,  the  Tubinares 
again  having  some  points  of  resemblance  to  the  storks  (Grallae).  The  Ceco- 
morphae  are  swimming  birds,  having  a  schizognathous  palate  and  the  angle  of 
the  mandible  truncate. 

An  albatross,  Diomedea  anglica,  occurs  in  the  Red  Crag,  Pliocene,  of 
England,  and  remains  of  gulls  are  numerous  in  the  Miocene  of  the  south  of 

^   Watson,  J/.,  Report  ou  the  Penguins  collectecl  by  tlie  Challenger  (Challenger  Reports,  vol.  VlI. 
Part  XVIII.),  1883. 


SüPEK-oRDER  IV  EUORNITHES  273 

France ;  and  it  is  of  interest  to  note  that  the  earliest  known  auk,  MancaUa 
mliforniensis,  from  the  Upper  Miocene  of  California,  was  a  highly  specialised 
and  flightless  form. 

Order  3.     QRALLAE. 

The  Grallae  are  a  group  of  wading  birds  having  a  schizognathous  skull  with- 
out  basipterygoid  processes  and  schizorhinal  nostrils.  The  order  embraces  the 
cranes,  snipe,  bustards,  and  rails,  and  includes  an  unusual  number  of  aberrant 
forms,  such  as  the  South  American  trumpeter,  Psopkia;  the  Seriema,  Cariama; 
and  the  New  Caledonian  Rhinochoetus,  birds  which  retain  some  of  the  characters 
of  their  ancestral  forms,  and  hence  being  more  generalised  than  their  modern 
relatives,  are  hird  to  fit  into  any  scheme  of  Classification. 

The  plovers  closely  approach  the  gulls  among  the  Cecomorphae^^  while 
through  Cariama  the  Grallae  point  towards  the  birds  of  prey,  and  there  is  a 
strong  and  probably  more  than  superficial  likeness  between  this  and  the 
equally  aberrant  accipitrine  secretary  bird. 

The  gigantic  birds  of  the  genus  Phororhacos,  and  their  allies  from  the 
Miocene  of  Patagonia,  are  gralline  birds  related  to  Cariama,  although  some 
structural  details  seem  to  point  towards  the  herons.  They  are  distinguished 
by  a  large  skull  having  a  high,  compressed,  and  sharply  hooked  beak,  and  by 
a  small  sternum  and  Shoulder  girdle ;  the  pubis,  save  the  anterior  end,  is 
lacking.  The  skull  of  the  largest  species,  Phororhacos  longissimus,  was  0*6  m. 
long,  and  the  cervical  vertebrae  1 3  cm.  across,  far  exceeding  in  their  dimensions 
those  of  any  other  bird.  Their  structure  suggests  that  they  were  cursorial 
birds  of  prey  in  their  habits.  These  highly  specialised  forms  are  from  the 
Santa  Cruz  beds  of  the  Miocene  of  Patagonia.  It  is  probable  that  Diatryma 
from  New  Mexico  is  related  to  these  birds.  A  crane,  Palaeogrus,  occurs  in 
the  Eocene  of  Italy ;  and  another,  Alefornis,  in  the  Eocene  of  Wyoming.  A 
rail,  Gi/psoniis,  is  found  in  the  Eocene  of  Montmatre. 


Order  4.     CHENOMORPHAE. 

The  Ghenmnorphae,  or  ducks,  after  excluding  one  or  two  debatable  species, 
form  a  sharply  defined  group  of  water-birds,  whose  skull  is  typically  desmo- 
gnathous,  either  by  the  direct  fusion  of  the  maxillo-palatines  or  their  indirect 
Union  through  the  ossified  narial  septum.  Low  basipterygoid  facettes  are 
present,  well  forward  on  the  sphenoid,  and  on"  these  the  pterygoids  slide, 
allowing  a  slight  motion  of  the  beak.  The  posterior  end  of  the  mandible  is 
produced  and  recurved. 

The  "outliers"  of  the  Chenomorphae  are  three  species  of  South  American 
birds  representing  the  genera  Palamedea  (or  Anhima)  and  Chauna,  which  form 
either  a  separate  order,  sub- order,  or  superfamily,  the  Palamedeae.  These 
birds  have  neither  webbed  feet  nor  duck-like  bills,  and  bear  a  slight  superficial 
resemblance  to  the  fowls,  although  anatomical  characters  place  them  near 
the  ducks. 

The  flamingoes  form  another  debatable  group,  assigned  by  some  to  the 

1  Tliat  Beddard  includes  botli  gulls  and  plovers  in  his  Limicolae  may  serve  as  au  illust.ration 
of  the  slight  variations  among  birds,  and  the  exteut  to  which  individual  opinion  enters  into  the 
classifyiug  of  birds. 

VOL.  II  "^ 


274 


AVES 


Cheiiomorphae,  by  others  to  the  Herodiones,  their  affinities  to  both  leading 
Huxley  to  place  them  in  a  separate  group  termed  Amphimorphae.  It  may  be 
that  we  have  in  the  flamingoes  the  survivors  of  a  group  from  which  both  the 
storks  and  ducks  were  derived,  since  the  group  is  an  old  one  and  its  i;ange 
formerly  much  more  extensive  than  at  j)resent.  The  earliest  known  member 
is  Scaniornis,  from  the  Cretaceous  of  Sweden,  while  the  allied  genus  Agnopterus 
comes  from  the  Eocene  of  the  Paris  Basin,  and  Elornis  from  the  Eocene  and 
Miocene.      Several    species    of    Palaeolodus,   a    shorter-legged   bird   than   the 

flamingo,  also  occur  in  the 
Miocene  of  France,  and  a 
true  Phoenicopferus  in  the 
Pliocene  of  Oregon  and 
Miocene  of  France. 

Gastornis,  from  the  Eocene 
of  Europe,  is  a  large  bird, 
placed  at  first  with  the 
ostriches,  but  more  generally 
regarded  as  an  aberrant 
member  of  the  Chenomorphae. 
It  is  remarkable  from  the 
fact  that  the  bones  of  the 
skull  seem  to  have  remained 
free  from  one  another 
throughout  life. 

Ducks  are  not  uncommon 
in  the  Miocene  of  France 
and  Pliocene  of  Oregon,  and 
a  large,  fiightless  species, 
Onemiornis  ccdcitrans,  occurs 
in  the  Pleistocene  of  New 
Zealand.  This  bird  well 
exemplifies  some  of  the  ditfi- 
culties  in  the  way  of  deter- 
mining  the  exact  affinities 
from  isolated  bones,  since 
from  the  tibia  Owen  considered  it  to  belong  with  the  Moas,  while  from  the 
sternum  Parker  believed  it  to  be  a  rail ;  the  discovery  of  the  skull  showed  it 
to  be  unequivocally  a  goose.  Numerous  species  of  Anas  (Fig.  373),  as  well 
as  isolated  representatives  of  Anser,  Cygnus,  Fuligula,  Spatula,  Mergus,  and  the 
like  are  known  from  the  late  Tertiary  of  various  European  localities. 


Anas  UancJiardi 
France.     Restoration  of  skeleton 


Fig.  373. 
Miliie-Edw.     Miocone ;    St.   Gerand-le-Puy, 


i  (after  Milne-Edwards). 


Order  5.     HERODII. 

The  Herodii,  containing  the  herons,  storks,  and  ibises,  may  be  defined  as 
wading  birds  with  unusually  long  legs,  having  desmognathous  skulls  without 
basipterygoid  processes,  and  (save  for  few  exceptions)  with  the  angle  of  the 
mandible  truncate,  the  exceptions  occurring  in  the  spoonbills,  Platalea. 

The  herons  appear  first  in  the  Lower  Eocene,  Proherodius  occurring  in 
England,  and  Gypsornis  and  Propelargus  from  the  Upper  Eocene  of  France. 
An  ibis,  Ihidopsis,  is  found  in  the  Upper  Eocene  of  England,  and  Ibidopodia  in 


SUPER-ORDER  IV  EUOBNITHES  275 

the  Lower  Mioceiie  of  France,  while  from  the  same  formation  and  locality 
comes  Leptoptüus,  now  confined  to  warmer  regions  of  Asia  and  Africa.  From 
the  Middle  Miocene  comes  a  true  heron,  Ardea,  and  above  that  the  species 
represented  are  of  existing  genera.     The  flamingoes  are  discussed  nnder  the 

Chenomorphae. 

Order  6.     STEGANOPODES. 

The  Sfeganopodes  include  the  pelicans,  cormorants,  gannets,  frigate 
birds,  and  tropic  birds,  and  form  a  fairly  homogeneous  group  of  birds  with 
a  desmognathous  skull,  a  sternum  with  a  feeble  keel,  on  the  forwardly  pro- 
duced  anterior  portion  of  which  the  lower  ends  of  the  clavicles  rest  and  are 
frequently  joined  by  anchylosis.  A  distinctive  external  feature  is  the  union  of 
all  four  toes  by  a  web. 

The  desmognathism  of  this  group,  as  indicated  by  the  species  that  have 
been  most  carefully  studied,  is  of  a  difFerent  nature  from  that  of  the  Accipitres, 
being  a  secondary  character  acquired  after  the  bird  has  been  hatched,  and  due 
to  the  extension  of  ossification  into  the  palatal  region,  which  finally  unites  the 
various  portions.  In  the  cormorants,  Fhalacrocoracidae,  and  probably  in  the 
gannets,  Sulidae,  this  is  concomitant  with  the  closing  of  the  external  nostrils, 
for  the  cormorants  when  hatched  are  schizognathous  and  holorhinal,  and  this 
condition  lasts  up  to  about  the  time  they  take  to  the  water.  The  changes 
that  occur  are  directly  connected  with  the  bird's  habits,  for  the  cormorants 
pursue  their  prey  beneath  the  surface,  while  the  gannets  plunge  down  upon  it 
from  above.  This  absence  of  nostrils  is  associated  with  absence  of  the  supra- 
orbital glands,  and  this  in"  turn  with  the  lack  of  the  depressions  to  contain 
them,  which  are  such  obvious  characters  in  the  skuUs  of  aquatic  birds  with 
open  nostrils,  such  as  ducks,  gulls,  petrels,  and  penguins. 

The  Steganopodes  seem  to  have  differentiated  early,  for  a  cormorant,  Gracu- 
lavus,  occurs  in  the  Cretaceous  of  the  United  States.  Cyphornis  magnus  is 
known  from  the  Eocene  of  Vancouver,  and  Prophaethon  shrubsolei  and 
Odontopteryx  toliapicus  from  the  London  Clay,  Lower  Eocene.  It  is  possible 
that  this  last  may  not  belong  to  the  order,  although  believed  to  be  related 
to  the  gannets ;  it  is  distinguished  by  having  the  mandible  armed  with 
tooth-like  projections.  The  genus  Phalacrocorax  ranges  from  the  Eocene  of 
Montmatre  to  the  present,  and  other  members  of  the  order  are  found  in  the 
Miocene  of  Europe  and  Pliocene  of  the  United  States. 

« 
Order  7.     OPISTHOCOMI. 

The  order  Opisthocomi  contains  but  a  single  species,  the  extraordinary 
hoactzin  (Opisfhocomus  cristatus)  of  South  America.  The  skull  is  schizo- 
gnathous, without  basipterygoid  facettes.  The  sternum  is  widest  posteriorly, 
and  the  keel  is  cut  away  in  front,  a  peculiarity  connected  with  the  presence 
of  a  large  crop ;  the  f urculum  is  anchylosed  to  the  coracoids  above  and  to  the 
sternum  below.  In  the  nestling  the  thumb  is  large,  clawed,  and  used  in 
climbing,  but  in  the  adult  it  is  clawless,  and  even  smaller  than  in  the  majority 
of  birds,  being  a  remarkable  instance  of  rapid  retrogression.  The  hoactzin 
seems  to  have.affinities  with  fowls,  on  the  one  band,  and  the  plantain-eaters, 
Musophagi,  on  the  other,  and  is  considered  as  a  survival  of  a  primitive  type, 


276  AVES  CLASSiv 

a  suppositioii   that   gathers   strength  from  the   presence   of    an   allied  form, 
Filholornis,  in  the  Upper  Eocene  of  Southern  France. 

Order  8.     GALLINAB. 

The  GaUinae  are  birds  having  a  typically  schizognathous  skull,  the  maxillo- 
palatines  being  (with  rare  exceptions)  widely  separated,  the  vomer  sometimes 
absent,  small  and  pointed  when  present;  there  are  basipterygoid  facettes  on  the 
sphenoid.  The  sternum  is  four-notched,  very  deeply  cleft  in  the  true  fowls, 
and  much  less  so  in  the  curassows  and  Australian  Megapodes,  the  other  two 
groups  included  in  the  order.  The  probable  affinities  of  the  fowls  with  the 
tinamous  have  already  been  noticed ;  through  the  sand-grouse,  Fterodetes,  they 
are  connected  with  the  pigeons,  Columbae,  both  of  which  are  placed  in  Orders 
by  themselves,  although  the  former  is  not  here  noted.  Another  order, 
Hemipodii,  is  usually  made  for  the  reception  of  the  small  birds  of  the  genera 
Coturnix  and  Fedionomus,  familiarly  known  as  button  quails  or  bush  quails, 
and  ranging  from  Spain  to  Australia. 

A  small,  generalised  form,  GaUinuloides,  nearly  related  to  the  existing 
Ortalis,  but  considered  as  representing  a  distinct  family,  has  been  described 
from  the  Green  Eiver  Eocene  of  Wyoming,  and  true  GaUinae  of  the  genera 
Falaeörtyx,  Taoperdix,  and  Tetrao  occur  in  the  Upper  Eocene  of  France.  The 
genus  Fhasianus,  not  found  native  in  Europe  as  an  existing  genus,  occurs  in 
the  Miocene  of  France.  Coturnix  dates  back  to  the  Eocene,  and  Coliimha  to 
the  Lower  Miocene  of  Europe. 

Order  9.     COLUMBAE. 

The  Columbae,  or  pigeons,  have  a  schizognathous  skull  and  schizorhinal 
nostrils,  a  point  wherein  they  differ  from  fowls.  The  furculum  is  U-shaped 
and  devoid  of  a  hypocleidium,  the  sternum  four-notched  and  normally  with 
a  deep  keel,  the  pigeons  as  a  rule  being  birds  of  powerful  flight.  The  angle 
of  the  mandible  is  usually  truncate,  and  the  deltoid  crest  of  the  humerus 
produced  into  a  point. 

Kemains  of  existing  genera  occur  from.  the  Miocene  upwards  in  various 
parts  of  the  world. 

Order  10.     ACCIPITRES. 

The  Accipitres,  as  here  considered,  contain  the  diurnal  birds  of  prey,  the 
owls,  the  American  vultures,  and  the  secretary  bird,  four  very  distinct  groups. 
They  have  an  imperfectly  desmognathous  skull,  the  spongy  maxillo-palatines 
being  only  partly  united  with  one  another,  and  in  some  species  even  free. 
Basipterygoid  facettes  are  absent  in  the  diurnal  birds  of  prey,  but  present  in 
the  other  members  of  the  order.  The  owls,  or  Striges,  are  thought  to  be 
related  to  the  Caprimulgi,  and  are  characterised  by  having  the  orbits  facing 
forwards,  and  by  the  reversion  of  the  outer  toe,  this  last  feature  being 
possessed  also  by  the  somewhat  exceptional  and  widely  distributed  osprey, 
Fandion. 

The  earliest  known  members  of  the  order  are  LitJiornis  from  the  London 
Clay,  Eocene,  Falaeocircus  from  the  Eocene  of  the  Paris  Basin,  and  Fuho  from 
the  Eocene  of  Wyoming.      Teracus,  Falaeohierax,  and  representatives  of  modern 


SUPER-ORDER  IV  EUORNITHES  277 

genera  are  found  in  the  Miocene  of  France.  Gypogeranus  occurs  in  the 
Miocene  of  Africa,  and  Palaeohorus,  a  form  allied  to  Polyborus,  comes  from  the 
Pliocene  of  Mexico.  Harpagornis,  a  bird  much  larger  than  any  existing  eagle, 
has  been  found  in  the  Pleistocene  of  New  Zealand. 

Order  11.     PSITTACI. 

The  Psittaci,  parrots,  have  a  desmggnathous  skull  devoid  of  basipterygoid 
facettes,  with  the  beak  so  hinged  to  the  cranium  as  to  permit  considerable 
movement.  The  quadrate  has  a  peculiar,  long  neck,  and  there  are  processes 
from  the  lachrymal,  post-frontal,  and  squamosal,  which  in  a  number  of  species 
unite  to  form  a  suborbital  bar,  a  feature  not  found  in  any  other  birds.  The 
tarsus  is  short,  the  outer  toe  reversed. 

Fossil  parrots  are  rare,  but  the  African  genus  Psittacus  is  found  in  the 
Lower  Miocene  of  France. 


Order  12.     PICARIAB. 

The  Picariae  comprise  such  a  variety  of  forms  that  it  has  been  termed  the 
"  avian  waste-basket,"  while  the  limits  of  the  group  and  its  subdivisions  are 
variously  defined  by  difFerent  authors.  The  well-marked  groups  embraced 
under  the  term  Picariae,  and  often,  or  usually,  given  the  rank  of  Orders,  are  as 
follows  : — Pici,  Alcedines,  Colii,  Trogones,  Coraciae,  Bucerotes,  Macrochires,  Capri- 
mulgi,  Cuculi,  Musophagi. 

That  this  is  not  a  natural  assemblage  may  be  considered  as  evident  from 
the  fact  that  no  diagnosis  based  on  osteological  characters  alone  can  be  framed 
to  include  all  members,  though  a  better  agreement  is  to  be  found  in  the 
pterylosis  and  muscles.  It  may  be  regarded  as  a  convenient  grouping  of 
heterogeneous  forms,  including  many  that  have  become  specialised  in  some 
ways,  while  at  the  same  time  retaining  other  characters  inherited  from  their 
ancestors,  and  distinguished  by  what  they  lack  rather  than  what  they  possess. 

The  sternum  is  variable,  but  the  manubrium  is  lacking,  or  small,  and  the 
posterior  margin  most  often  four-notched.  The  hypotarsus  never  contains  the 
number  of  tendinal  perforations  found  in  the  Passeres,  and  there  are  often 
peculiarities  in  the  arrangement  of  the  toes ;  thus  some  swifts  and  goatsuckers 
have  the  number  of  phalanges  2,  3,  3,  3 ;  the  woodpeckers,  cuckoos,  and 
toucans  have  the  fourth  toe  reversed  ;  in  the  colies  the  first  toe  may  be  turned 
forwards  ;  and  in  the  trogons  the  first  and  second  toes  are  directed  backwards. 
The  Pici,  characterised  by  a  degenerate  palatal  structure,  and  the  decurved 
end  of  the  scapula,  are  united  by  Fürbringer  to  form  his  Pico-Passeres. 

Through  the  plaintain-eaters,  Musophagi,  the  Picariae  seem  to  point  to  a 
distant  connection  with  Opisthocomus  and  the  fowls,  while  the  Caprimulgi  are 
considered  as  related  to  the  owls,  and  through  the  generalised  Asiatic  tree- 
swifts,  Macropteryx,  from  which  we  pass  to  the  true  swifts,  Micropodidae,  and 
thence  to  the  humming-birds. 

Unitornis,  related  to  the  woodpeckers,  and  Cryptomis,  a  relative  of  the 
hornbills,  occur  respectively  in  the  Eocene  of  Wyoming  and  France.  Cypselus, 
Limnatornis,  a  hoopoe,  Trogon,  and  Necrornis,  one  of  the  Musophagidae,  are  from 
the  Miocene  of  France,  the  last  two  hinting  at  ä  former  more  northerly 
extension  of  the  African  avifauna. 


278  AVES  ciAss  IV 

Order  13.     PASSERES. 

The  Order  Passeres  embraces  about  one-half,  or,  in  round  numbers,  6000 
species  of  existing  birds,  mostly  of  small  size,  the  raven  being  the  giant  of  the 
Order,  widely  distributed  over  the  globe.  The  skull  is  aegithognathous  ;  ^  the 
sternum  bears  a  Y-shaped  manubrium,  and  is  deeply  two-notched  behind 
(Compophaga  and  a  few  others  are  four-notched).  The  hypocleidium  (inter- 
clavicle)  is  well  developed  save  in  Menura  and  Atrichia,  and  almost  rests  upon 
the  anterior  part  of  the  sternal  keel. 

With^the  Single  exception  of  Cholornis,  in  which  the  fourth  toe  is  a  m^e 
vestige,  there  are  three  toes  in  front  and  one  behind ;  the  hypotarsus  is  more 
highly  specialised  than  in  any  other  group,  having  four  large  tendinal 
perforations,  and  sometimes  two  smaller  ones  in  addition ;  the  typical  number 
of  presacral  vertebrae  is  nineteen,  fourteen  of  which  are  cervical,  the 
Australian  genus  Petroica  being  exceptional  in  having  thirteen.  The  skeletal 
variations  in  all  this  great  group  of  birds  are  small,  so  small  indeed  that  it  is 
almost  impossible  to  use  them  in  making  subdivisions,  external  differences, 
such  as  slight  variations  in  the  proportions  of  the  toes  and  form  of  the  beak 
being  used  for  this  purpose.  , 

It  is  instructive  to  note  that  Huxley  and  Fürbringer,  who  used  skeletal 
characters,  made  two  families  of  the  Passeres,  while  Sharpe,  using  external 
characters,  makes  forty-nine.  The  Australian  lyre  birds  (Menuridae),  however, 
form  a  distinct  group,  and  so  do  the  Asiatic  broadbills  {Eurylaimidae),  as 
well  as  the  American  tyrant  flycatchers  (Tyrannidae),  and  their  relatives ; 
also  the  ant  thrushes  (Formicariidae),  and  their  relatives.  The  order  dates 
from  the  Eocene,  Palaeospiza^  coming  from  the  Florissant  Shales  of  Wyoming, 
and  Palaegithalus  and  a  starling  (LauriUardia)  from  the  Eocene  of  the  Paris 
Basin.  Above  that  horizon  more  occur,  but  the  small  size  of  most  Passeres 
is  a  good  reason  for  the  lack  of  discovery,  or  lack  of  preservation,  of  many 
species. 

In  conclusion,  it  may  be  well  to  repeat  that  our  knowledge  of  the  phylogeny 
of  the  various  groups  of  birds  is  very  imperfect,  and  that  most  of  the  fossil 
forms  are  not  only  representatives  of  well-known  families,  but  often  belong  to 
the  same  genera  as  species  now  living  in  the  same  geographic  area  in  which 
the  fossils  occur.  This  is  in  marked  contrast  with  what  we  find  in  the 
Mammalia,  for  not  a  family  of  these  found  in  the  Eocene,  and  few  from  the 
Miocene,  are  represented  by  living  species. 

From  the  fact  that  the  majority  of  birds  possess  the  power  of  flight  they 
throw  little  light  on  the  problems  of  former  land  connections  and  lines  of 
distribution,  although  they  may  to  some  extent  indicate  climatic  differences 
between  the  past  and  the  present.  There  is  a  great  gap  between  the  birds  of 
the  Eocene  and  the  toothed  birds  of  the  Cretaceous,  and  a  greater  one  between 
these  and  the  Jurassic  Archaeopteryx,  while  the  point  at  which  birds  diverged 
from  reptiles,  and  put  on  their  dress  of  feathers,  is  wholly  unknown. 

[The  preceding  chapter  on  Avcs  has  been  revised,  and  in  large  part  rewritten  by  Mr. 
Frederic  A.  Lucas,  of  the  United  States  National  Museum  at  Washington,  D.O. — Editor.] 

1  Parker,  W.  K.,  On  the  Skull  of  Aegithognathous  Birds  (Trans.  Zool.  Soc.  London,  Part  L  vol. 
IX.  pp.  289-352  ;  Part  IL  vol.  X.  pp.  251-314),  1873,  1878. 

-  This  specimen  seems  to  have  been  lost,  but  one  is  inclined  to  doubt  from  the  figure  that  this 
bird  is  truly  a  passerine. 


INDEX 


[Names  of  genera  regarded  as  Synonyms  are  printed  in  italics,  all  otliers  in  Roman  type. 


AcantMas,  20 
Acanthobatis,  42 
Acanthoflerma,  110 
Acantho<les,  21 
Acanthodopsis,  21 
Acanthoesms,  21 
Acanthoiiemns,  108 
Acanthopleurus,  110 
Acanthostoma,  127 
Acanthurus,  107 
Acanus,  105 
Acentrophorus,  SO 
Aeheloma,  131 
Achelonia,  200 
Acherontemys,  201 
Aclchelys,  200 
Acipenser,  74 
Acondylacanthus,  4S 
Acrodobatls,  31 
Acrodus,  28 
Acrolepis,  77 
Acrosaurus,  151 
Acteosaurus,  152 
Actinobatis,  42 
Actinodon,  129 
Adocus,  201 
Adriosaurus,  152 
Aeehmodus,  80 
Aelurosaiirus,  183 
Aeolodon,  214 
Aepyomis,  209 
Aethalion,  94 
Aetobatis,  44 
Aetosaurus,  211 
Agama,  162 
Aganodu.s,  23 
Agassizodits,  27 
Agathawmis,  244 
Agnopterus,  274 
Agompluis,  201 
Aigialosaiu'us,  152 
Albula,  95 
Aletomis,  273 
Alexandrinuiii,  42 
Alligator,  222 
Alligatorellus,  21t> 
AUigatoriura,  215 
Allosanrus,  229 
Alopecias,  34 
Alopiopsi.s,  32 
Alosa,  97 
Amblyodoii,  125 
Amblypterus,  75 
AmhlyuTu.i,  80 
Amia,  92 
Araiopsis,  92 
Ammosaurus,  228 
ATnphibamus,  125 
-1  iiiphicentrum,  78 
ImpMcoelas,  235 
[iiipMcotylus,  210 
I  iiiphiemyv,  201 
\inphisbaena,  100 


Amphiwtiuin,  107 
Amphisyle,  108 
Amylodon,  48 
Amyzon,  101 
Anapterus,  99 
Aiiarosaurus,  173 
Anas,  274 
Anchisaurus,  228 
Ancistrodon,  110 
Andrias,  137 
Anenchdum,  107 
Anguisaurios,  151 
Anhima,  273 

i  Anisodexis,  131 

i  Aiiodontacanthus,  25 
Aiiogmius,  97 
Anomalichthys,  61 
Aiiomalopteryx,  271 
Anomoeodus,  88 
Anostira,  201 
Anser,  274 

j  Anthodon,  181 

I  Anthracosaurus,  132 

i  AntlicHius,  38 

I  Aijatosauriis,  230 
Ajwdodus,  70 
Aphelosaurus,  148 
Aplax,  200 
Aprionodon,  32 
Apsopelix,  108 
Apteryx,  271 

I  Arcliaeobatis,  37 

I  Archaeobolus,  149 

I  Archaeogadus,  99 
Archaeopteryx,  264 
Archaeoteuthis,  52 
Arcl\^eotriton,  137 
Arcliegosaurus,  128 
Archeion,  198 
Archichthys,  71 

;  Arctosaurus,  228 
Ardea,  275 

!  Ardeosaurus,  151 

I  Argillochelys,  198 
Argyrosaurus,  236 
Aristodesnius,  181 
Aristosiichus,  231 
Aiomochelys,  201 
Arpngodtis,  27 
Aspidicl]jthys,  61 
Aspidodus,  36 

I  Asi)idorhynchns,  88 
Asiiius,  101 

1  Astei-acanthus,  28 

1  Asteroderimis,  41 

]  Asterodon,  81 

1  Asterolepis,  57 

'  Asteroplax,  61 
AsttMoptychius,  48 

I  Astei'osteus,  58 

I  AstrcboditJ^,  37 
Atelraspis,  54 
Atherina,  108 


I  Atlierstonia,  77 

AÜantosaurus,  233 
!  Atoposaurus,  216 
I  Atrichia,  278 
j  Attakeopsis,  92 
I  Aublysodon,  230 
I  Auchenaspis,  55 

Aidacostexis,  45 

Aulodus,  43 
I  Aulorhamphus,  107 

Aulostonia,  108 

Aiduxacanthus,  47 

Auxis,  108 

Axestus,  196 

Baena,  20 

Balistes,  110 
Baptanodon,  171 

;  Bapteniys,  201 
Baptornis,  267 
Barbus,  101 
Bathygnathus,  228 
Bathythrissa,  94 
Belemnacanthus,  58 
Belemnobatis,  41 
Belodon,  210 
ßelone,  103 

i  Belonorhynchus,  74 

[  Belonostomus,  89 

I  Belonostomxis,  75 

i  Bernissartia,  210 

1  Birkenia,  53 

'  Blochins,  109 

I  Boavus,  165 

,  Bolboden,  182 
Bothrioeps,  131 
Bothriolepis,  58 
Bothriospondylm,  236 
Bottosaurus,  222 
Brnchyacanthus,  22 
Brachydectes,  126 
Brachydirus,  59 
Bracliymylus,  47 

!  Brachyops,  131 
Brachysaunis,  159 
Branchiosaurus,  124 
Brimosaunis,  177 
Brithoi)us,  183 
Brontosaurus,  235 
Brosmius.  102 
Brychaetus,  97 
Bubo,  270 
Biicklandiuni,  101 
Bufo,  138 
Bfizenos,  38 

Caiman,  222 

Calamoiclithys,  73 
Calamopleurus,  108 
Calamospondylus,  231 

:  Calamostoma,  109 
Cidaviosfoma,  107 

I  Callibraclnon.  149 


Callopristodus,  39 
Callopterus,  83 
Callorhynclius,  48 
Camarasauriis,  233 
Campodus,  27 
Camptonotu^i,  288 
Cainptosaurus,  238 
Campylognathiis,  252 
Campylopriou,  27 
Canobins,  75 
Capitodiifi,  105 
Capitosaurus,  132 

j  Carangopsis,  108 

1  Caranx,  108 

i  Carcharias,  32 

!  Carcharodon,  34 

i  Carcliaropsis,  20 
Cariama,  273 
Carsosaurus,  152 

'  Casuarius,  208 

!  Cataplenra,  198 
VatopUrns,  62 

I  Catopterus,  79 

,  Caturus,  83 
Cenchrodus,  82 
Centrina,  20 
C«ntroiepis,  77 

i  Cevtrophoroides,  26 
Ceutropliorus,  26 
Cephalaspis,  54 
Cephalopterits,  51 
Ceraspis,  58 
Ceraterpetuui,  120 

I  Ceratochelys,  204 
Ceratodus,  64 

j  Ceratops,  245 

:  Ceratosaunis,  228 

I  Cestracioii,  29 

I  Cetiosaurus,  233 

j  Cetorhiuus,  35 

[  rhalcodm,  30 

!  Chalcosanrus,  130 

j  Champsosaurus,  I.'jO 
CharocDdu»,  37,  71 
Charitosoinus,  100 
Chauna,  273 
Cheiracantlius,  21 
Cheirodopsis,  79 
Cheirodus,  78 
Cheirolepis,  75 
Cheii-othrix,  100 
Chelidosjiurus,  129 

,  Chelodiiia,  205 
Chelone,  198 
Vheloufinys,  20«? 
Chelydra,  201 
Chelyopliorus,  59 
Chelyopsis,  198 
Chelys,  205 
Chdytkerium,  204 
Cbilonyx,  182 
Chiloscylliiiin,  31 

I  Chiniaera,  48 


280 


TEXT -BOOK  OF  PALAEONTOLOGY 


Chimaeracanthus,  47 
Chiniaeropsis,  40 
Chitonodtis,  36 
Chitra,  1P6 
Chitracephalus,  200 
Chlamydoselache,  26 
Cholornis,  278 
Chomatodiis,  38 
Chondrosteosaurus,  23( 
Chondrosteus,  73 
Clirysophrys,  105 
Cimochelys,  198 
Cimoliasaurus,  177 
Cimolichthys,  98 
Cinixys,  203 
Cinosternuiii,  201 
Ciiiothorax,  203 
Cistudo,  203   , 
Cladodus,  19 
Cladoselache,  19 
Cladyodon,  228 
Claosaurus,  241 
Claudius,  201 
Cleithrolepis,  81 
Clemmys,  203 
Clepsydrops,  148 
Clepsysaurus,  228 
Clidastes,  159 
Climatius,  22 
Climaxodus,  38 
Cliorhizodon,  183 
Clupoa, 96 
Cnemiornis,  274 
Coccoderina,  72 
Coccolepis,  77 
Coccosteus,  59 
Cochleosaurus,  129 
Cochliodus,  35 
Cocytinus,  126 
Coelacanthus,  72 
Coelodus,  88 
Coelolepis,  51 
Coelosaurus,  230 
Coelurus,  231 
Colobodus,  81 
Colossochelys,  203 
Colosteus,  126 
Coluber,  165 
Colymbosaurus,  177 
Compsacanthus,  23 
Compseinys,  208 
Compsognathus,  230 
Conchiopsis,  72 
Conchiosaurus,  175 
Conchodus,  63 
Conchopoma,  62 
Conophaga,  278 
Coi>odus,  37 
Corax,  34 
Cosmolepis,  77 
Cosmoptychius,  77 
Coturnix,  276 
Crataeomus,  243 
Crenilepis,  80 
Cricosanrus,  215 
Cricotus,  131 
Crocodiieimus,  214 
Crossopholis,  74 
Crotalus,  164 
Cryphiolepis,  77 
Cryptobranchus,  137 
Cryptoclidus,  177 
Cryptomis,  277 
Ctenacanthus,  48 
Ctenodus,  63 
CUnopetahis,  39 
Ctenoptychius,  39 
Curtodns,  28 
Cyamodus,  188 
Cyathaspis,  53 
Cybium,  108 
Cyclemys,  203 
Cyclobatis,  42 
Cycloptychius,  76 
Cyclotosaurus,  133 
Cychirns,  92 


Cycnorhamphus,  253 
Cygnus,  274 
Cymatosaurus,  173 
Cymböspondylus,  171 
Cynochampsa,  183 
Cynodraco,  183 
Cynoguatluis,  183 
Cyuopodius,  49 
Cynosuchus,  183 

!  Cyphoruis,  275 

I  Cypriims,  101 

j  Cypselus,  277  ' 

;  Daccoclielys,  205 
;  Dactylalm,  39 
i  Dactylolepis,  81 
I  Dactylosaurus,  173 
I  Dakosaurus,  215 
;  Damonia,  203 
Daiuibiosaurus,  243 
Uapedius,  80 
Dapedoglosstos,  97 
Daptinus,  96 
Dasylepis,  55 
üawsonia,  125 
üeltodus,  36 
Deltoptychius,  36 
Dendrerpetou,  130 
Dendrodus,  70 
Dcndroptychius,  71 
Dercetis,  97 
Dermatochelys,  199 
Dermochelys,  197 
Dermodactylus,  254 
Deutorosaurus,  183 
Diadectes,  182 
Diadeiaodou,  184 
Diastichus,  101 
Diatryma,  269,  273 
Diceutrodus,  20 
Dichelodus,  36 
Didonins,  246 
J)icrenodus,  20 
Dictaea,  38 
Dictyolepis,  55 
Dictyopyge,  79 
Dicynodon, 187 
Didus,  272 
Didymaspis,  55 
Didymodus,  23,  25 
Dimetrodon,  148 
Dimodosaurus,  22S 
Dimorphodoii,  251 
Diuichthys,  59 
Dinornis,  270 
Dinosaurus,  183 
Diodou, 110 
Diomedea,  272 
Diopecephalus,  253 
Diplacanthus,  22 
Diplaspis,  53 
Diplocynodon,  221 
Diplodocus,  236 
Diplodus,  23 
Diploglossus,  162 
Diplognathus,  61 
Diplomystus,  96 
Diplopterus,  71 
Diplosaiirus,  216 
Diplovertebron,  131 
Diplurus,  72 
Dipriacanthus,  49 
Dipristis,  48 
Dipterus,  62 
Diracodati,  242 
Dirrhizodon,  32 
Uiscosaurus,  129 
Dissorophus,  131 
Disticholepis,  84 
Ditaxiodus,  83 
Ditrochosaurus,  150 
Dittodm,  71 
Dolichorhynciius,  178 
Dolichosaurus,  152 
Dolicliosoma,  128 
Doratorhynchus,  255 


Dorygnathus,  252 
Dorypterus,  79 
Drepanacanthiis,  49 
Drepanaspis,  51 
Drepanephorus,  29 
Dromaeus,  268 
Dryasaurus,  238 
Di'yptosaurus,  230 
Dnctor,  108 
Dules,  105 
Dynatobatis,  42 
Dyoplax,  211 

Echeneis,  108 
Echidnocephalus,  97 
Echinodon,  243 
Echinorhinus,  26 
Kctocynodon,  182 
Bdaphodon,  48 
Edestosaurns,  159 
Edestus,  27 
Elaphis,  165 
Elasiiiodectes,  48 
Elasmodus,  48 
Elasmognathiis,  48 
Elasniosaurus,  178 
Elginia,  181 
Elonichthys,  77 
Elopopsis,  94 
Elops,  94 
Elornis,  274 
Blseya,  205 
Einbaphias,  177 
Embolophorus,  149 
Empedias,  182 

i  Empedoceles,  182 

I  Empo,  99 

1  EiHvdura,  205 

j  Euiys,  202 

I  Enaliochelys,  200 

I  Enalioniis,  267 
Enchodus,  98 
Engraulis,  97 
Eomyrus,  101 
Eosaurus,  132 
Eosphargis,  197 
Epicampodon,  228 
Epiceratodus,  64 
Epicordylus,  131 
Episcoposaurus,  210 
Equula,  108 
Eretmosaurus,  177 
Erisichthe,  91 
Brismacaiithus,  49 
Erpetosaurus,  211 
Erquelinnesia,  198 
Eryninochelys,  205 
Eryops,  131 
Esox,  100 
Eucamerotus,  236 
EucephcUaspis,  54 
Euchirosaurus,  129 
Endastes,  198 
Euctenius,  49 
Eugnathus,  83 
Eukeraspis,  55 
Eumylodus,  48 
Eupiianerops,  54 
Euposaurus,  151 
Eurapteryx,  271 

\  Euryarthra,  41 
Euryaspis,  200 
Burycarpus,  187 
Eurycormus,  83 
Eurygnathns,  98 
Euryiepis,  75 
Burynotus,  78 
Burypholis,  98 
Eurysternum,  200 
Euscelosaurus,  228 
Eusemius,  84 
Eusthenopteron,  71 
Euthacanthus,  22 
Buthynotus,  90 

Fllholornis,  276 


i  Fissodus,  39 
!  Fistularia,  108 
;  Fuligula,  274 

:  Gadus,  102 

I  Galeocerdo,  3-2 

!  Galesaurus,  182      "' 

I  Galeus,  32 

j  Galliiuiloides,  276 

I  Gampsacanthus,  49 

I  Ganodus,  47 

I  Gandodihs,  71 

Ganopristodvs,  62 

Geister  onemus,  108 

Gastornis,  274 

Gastrodus,  71 

Gaudrya,  129 

Gavialis,  221 

Gamalosxichns,  220 

Geikia,  187 

Geisacanthus,  48 

Genyornis,  269 

Geosaurus,  215 

Gerres,  105 

Gillicus,  95 

Ginglymostoma,  31 

Glossochelys,  198 

Glossodus,  39 

Glyptaspis,  61 

Glyptokiemus,  71 

Glyptdepis,  70 

Glyptopomus,  71 

Glyptosaurus,  162 

Glyptosteus,  58 

Gnathacanthus,  49 

Gobio,  101 

Gomphognathus,  184 

Gonatodus,  75 

Goudwanosaurus,  131 

Goniobatis,  44 

Goniochelys,  201 

Gotiiodus,  26 

Gonioglyptus,  134 

Goniopholis,  216 

Gordonia,  187 

Gorgonops,  183 
I  Graculavus,  275 
I  Graphivirus,  72 
i  Gresslyosaurus,  228 

Griphosaurus,  264 

Gymnodus,  110 

Gypochelys,  201 

Gypogeranus,  277 

Gypsornis,  273,  274 

Gyracanthus,  49 

Gyrodus,  85 
i  Gyrolepis,  77 

Gyroptychius,  71 

Gyrosteus,  73 

;  Hadrianus,  203 

Jlailrnsimrus,  240 

Huinosoiin's,  157 
;  Halec,  99 
j  Halieus,  272 
'  Hallopus,  231 

Halosaurus,  97 
i  Haplacanthus,  20 
j  HaiJtodus,  148 
I  Hcirpacodus,  39 
j  Harpagornis,  277 
!  Hatteria,  151 
!  Helagris,  165 
1  Helemys,  207 
i  Heliarchon,  137 

Helicoprion,  27 
!  Heliobatis,  42 
I  Heliodm,  63 
I  Helodus,  35,  36 

Hemicydaspis,  54 

Hemiiopas,  82 
!  Heraipristis,  32 
1  Hemirhynchus,  106 
j  Hemithyrsites,  107 

Heptadiodon,  110 
'  Heptanchns,  25 


INDEX 


281 


Heptanema,  72 
Hesperornis,  20(5 
Heteracanthus,  49 
Heterodontus,  29 
Heterdepidotus,  83 
Heteropython,  165 
Heterosteus,  60 
Heterostrophus,  81 
Heterothrissops,  90 
Hexunchus,  25 
Histionotus,  84 
HolacanthodeSf  21 
Holaspis,  53 
Hdcodon,  98 
Bolcodus,  157 
Holcolepis,  94 
Holocentrum,  104 
Holopha.gus,  72 
Holops,  220 
Holoptychius,  70 
Holosaurus,  158 
Holosteus,  103 
llomacanthus,  48 
Homaeosaurus,  151 
Homalodus,  37 
Homoeolepis,  80 
Homopus,  203 
Homosteus,  60 
Homothorax,  58 
Hoplopteryx,  104 
Hoplopygus,  72 
Hoplosaurus,  243 
Hybocladodus,  20 
Hybodus,  28 
Hydraspis,  205 
Hydromedusa,  205 
Hydropelta,  206 
Hylaeobatrachus,  137 
Hylaeochampsa,  215 
Hylaeochelys,  206 
Hylerpetou,  125 
Hylonomus,  125 
Hyloplesion,  125 
Hyopnous,  182 
Hypelornis,  269 
Hyperodapedon,  149 
Hypoprion,  32 
Hyposaurus.  216 
Hypsilophoidon,  238 
llypsirophus,  230 
Hypsocormus,  90 
Hypsodon,  95 

Ibldopodla,  274 
Ibidopsis,  274 
Ichthyodectes,  95 
IchthyorhynchiTS,  74 
Ichthyornis,  267 
Ichthyosaurus,  171 
Ichthyotringa,  99 
Ictiiiocephalus,  22 
Idiochelys,  206  ' 
Iguana,  162 
Iguanavus,  162 
Iguanodoii,  238 
Ischnacanthus,  22 
Ischyodus,  47 
Ischypterus,  80 
IschyrocepJmlus,  98 
Ischyrodon,  177 
Isodectes,  182 
Isopholis,  85 
Istieus,  94 
Isurichthys,  108 

Jacare,  222 

Janassa,  38 

Kadaliosaurus,  148 

Keirognathus,  187 
Keraterpeton,  126 
Kinixys,  203 
Kinosternon,  201 

Labraz,  105 

Labrosaurus,  229 
Labrus,  103 


l^abyrinthodon,  134 

l>,acerta,  162 

Laelaps,  230 

Lambdodus,  20 

l^amiia,  34 

Lamnodn^,  70 

Lanarkia,  51 

Laosaurus,  238 

Lariosaurus,  172 

Lasanius,  53 

Lates,  105 

Latonia,  139 

Laurillardia,  278 

Lebias,  100 

Lecracanthus,  49 

l.elodon,  159 

r.emboiiax,  198 

Lepidopoides,  107 

Lepidopus,  107 

Lepidosteus,  89 

Lepidotus,  82 

Lepracanthus,  48 

Leptamnthus,  47 

Leptecodon,  98 

Leptolepis,  93 

Leptophractus,  126 

Leptoptilus,  275 

Leptorhamphus,  221 

I.eptorhynchus,  221 

Leptosomus,  99 

Jjeptotrachelus,  98 

Lestosaums,  157 

Leuciscus,  101 

Libys,  72 

Lichia,  108 

Ijimnatornis,  277 

Ivimnerpeton,  126 

Limnophis,  165 

Limnosaurus,  241 

Liodesmus,  92 

Liodon,  157 

IJognathus,  59 

Liopleurodon,  177 

Lisgodus,  38 

Lispacanthus,  48 

Lithophis,  165 

J^ophacanthus,  23 

Lophiurvs,  92 

Lophodus,  36 

Loxomma,  132 
!  Lutremys,  202 
I  Lycosaurus,  183 
!  Lysorophus,  149 
'  Lystrosaumis,  187 

Lytoloma,  198 

Macellodus,  162 

Machaeracaiithus,  49 
Machimosaurus,  217 
Macrepistius,  84 
MaerocJielys,  197,  201 
Macroclemmys,  201 
Macromerion,  132 
Macromirosaurus,  172 
Macropetalichthys,  58 
Macropoma,  73 
Macropteryx,  277 
Macrorhipis,  92 
Macrorhynchus,  215 

:  Macrosaurus,  151 

i  Macrosemius,  84 

I  Mallotus,  97 

!  Mancalla,  273 
Mastodonsaurus,  134 
Mauisaurus,  177 
Megalania,  163 
Megalapteryx,  271 
Megalichthys,  71 
Megalneusaurus,  178 
Megalobatrachus,  137 
Megalolepis,  108 
ilegalops,  94 
Megalosaurus,  229 
Megalotriton,  137 
Megalurus,  91 
Megaplenron,  64 


Megapus,  100 

Megasternum,  207 

Megütopivs,  100 

Melaneri>eton,  125 

Meletta,  97 

MclittomaZepis,  55 

Melosaurus,  180 

Menaspis,  36 

Mene,  108 

Menura,  278 

Mergus,  274 

Merwtodon,  28- 

Mesacanthus,  21 

Mesiteia,  31 

Mesodoii,  87 

Mesogaster,  108 

Mesoganiph^is,  37 

Mesölepis,  78 

Mesolei)tos,  152 

Mesolophodus,  39 

Mesopteryx,  271 

Mesosaurus,  150 

Mesturus,  88 

Metopo.canthtis,  46 
i  Metopias,  132 

Metoposaurus,  132 

Metriorhynchus,  215 

Microbrachis,  126     , 

Microbrachius,  58 

Microdou,  86 

Microgomphodon,  184 

Miolania,  204 

Mioplosus,  105 

Mltsukurina,  33 
I  Mixosaurus,  171 
!  Mdge,  137 
!  Molgophis,  128 
I  Morosaurus,  235 
'  Mosasaurus,  159 
,  Mugil,  108 
'  Muraenosaurus,  177 
i  Mustelus,  32 
I  Mydas,  198 
I  Myliobatis,  44 
;  Mylognathus,  48 
I  Mylorhina,  44 
j  Mylostoma,  61 
i  Myriacanthus,  46 
!  Myriolepis,  77 
1  Myripristis,  104 
!  Mystriosaunis,  213 

I  NannosuchiLs,  217 

[  Nanosaurus,  238 
i  Naosaurus,  149 
Narcine,  42 
Narcöbatis,  42 
Narcodes,  57 
Necrornis,  277 
1  Nemacanthus,  49 
I  Nemachilus,  101 
i  Nematoptychius,  76 
I  Nemopteryx,  102 
I  Nephrotus,  82 
j  Neiisticosanrtis,  173 
'  Xicoria,  203 
I  Nodosaurus,  245 

Notaeus,  92 
I  Notagogus,  84 
I  Nothosaurus,  173 
Notidanus,  25 
Notiosaurus,  163 
Xotogoneus,  100 
Nummopalatus,  103 
1  Nyctodactylus,  253 
I  Nythosaurus,  182 

Ocadia,  203 

!  Ochlodus,  23 

I  Ocydromus,  272 

j  Odontawnthus,  57 

I  Odontaspis,  33 

I  Odonteus,  103 
Odoutopteryx,  275 
Oenoscopus,  92 
OesU^ephalus,  126 


Oligobelus,  101 
Oligopleurus,  92 
Oligosaurus,  243 
Oligosimus,  177 
Omphalodus,  82 
Onchiodon,  129 
Onchus,  48 
Oncobatis,  42 
Ophiderpeton ,  128 
Ophiopsis,  84 
Ophthalmosiiunis,  171 
Opisthocomus,  275 
Opisthomyzoii,  108 
Opi8thopter>-x,  9t» 
Opsigonus,  92 
Oracanthus,  49 
Orcynus,  108 
Ornithocephcdus,  253 
Omithocheirus,  255 
Omithodesmus,  255 
Omithomimus,  230 
Ornithopsis,  236 
Omithostonm,  254 
Ornithosuchus,  211 
Orodus,  27 
OrophosauruM,  177 
Ortalis,  276 
Orthacanthus,  23 
Orthacodus,  33 
Orthagoriscus,  110 
Orthocosta,  126 
Orthopleuroduf,  36 
Orthopus,  183 
Osmeroides,  94 
Osteoglossum,  97 
Osteolepis,  71 
Osteopygis,  198 
Ostracion,  110 
Oterognathua,  158 
Otocoelus,  181 
Otodus,  33 
Oudenodoii,  187 
Oxydontosaurus,  221 
Oxyglossus,  138 
Oxygnathus,  77 
Oxyrhina,  34 

Pachycormus,  90 

Pachygonia,  134 
Pachylepis,  51 
Pachymylus,  47 
Pachypleui-a,  173 
l'achyrhyuchus,  198 
Palaeaspis,  53 
Palaedaphus,  63 
Palaeeudyptes,  272 
Palaegithalus,  278 
Palaeobalistum,  88 
Palaeobates,  28 
Palaeobatrachus,  138 
Palaeoborus,  277 
Palaeocircus,  276 
Palaeogrus,  273 
Palaeohatteria,  147 
PalaeohierdX,  276 
Palaeolodus,  274 
Paloemnedtisa,  200 
Palaeomyhis,  45 
Palaeoniscus,  76 
Palaeophis,  165 
Palaeopython,  165 
Palaeorhynchus,  106 
Palaeornis,  255 
Palaeortyx,  276 
Palaeosaurus,  228 
Palaeoscylliuni,  31 
PalaeospheniscHS,  272 
Palaeospinax,  29 
Palaeospiza,  278 
Palaeospondylus,  17 
P(d((eoteuthij>,  52 
Palaeovaraiius,  162 
Palamedea,  273 
Palapteryx,  271 
Palimphyes,  108 
Pomphractus,  58 


282 


TEXT -BOOK  OF  PALAEONTOLOGY 


Fand  i  011,  27 6 
Pantylus,  182 
Pappichthys,  92 
Parachelys,  20(5 
Parai)erca,  105 
Parascopelus,  99 
Parasuchus,  210 
Pareiasaurus,  ISO 
Parexus,  22 
Pariotichus,  182 
Parioxys,  131 
Passalödon,  48 
Pastinaca,  44 
Pedionomus,  276 
Pelagorhynchus,  it8 
Pelagosaurus,  214 
Pelates,  105 
Pehcapterus,  91- 
Pelioii,  125 
Pelobatochelys,  200 
Pelomedusa,  205 
Peloneustes,  177 
Pelophilus,  139 
Pdorosaurus,  236 
Pelosaurus,  125 
Peltocephalus,  205 
Peltochelys,  201 
Peltodm,  38 
Pelycorapis,  108 
Peripristis,  31» 
Peritresius,  199 
Petalodopsis,  3i> 
Petalodus,  38 
Petalopteryx,  84 
Petalorhynchus,  38 
Petroica,  278 
Petrosuchus,  215 
Phalacrocorax,  275 
Phaneropleuron,  63 
Phanerosaurus,  181 
Phareodiis,  97 
Pharyngodopüus,  103 
Phasiaiius,  276 
Phlegethoutia,  128 
Phlyctaenaspis,  59 
Phoderacanthus,  49 
Phoebodus,  20 
Phoenicopterus,  274 
Pholidophorus,  85 
Pholidopleurus,  84 
Pholidosaiirns,  215 
Pholidurus,  74 
Phorcynis,  39 
Phororhacos,  273 
Phosphorosaurus,  159 
Phrynops,  205 
Phycis,  102 
Phyllodus,  103 
Physodon,  32 
Physonemus,  49 
Phytosaurus,  210 
Pinacodm,  37 
Piptomerus,  177 
Pisodus,  95 
Pistosaiirus,  175 
Placodus,  187 
PUicostens,  51 
Placothorax,  58 
Plastomenns,  196 
Platalea,  274 
Platax,  107 
Platecarpus,  157 
Platemys,  205 
Plateosauriis,  228 
Platyacdnthus,  49 
Platychelys,  201,  207 
Platygruithus,  70 
Platyops,  130 
Platypodosaurus,  187 
Platyrhiiia,  41 
Platysomus,  79 
Platystenuim,  202 
Plectrodus,  55 
Plectrolepis,  78 
Plesiochelys,  206 
Phsiodus,  82 


Plesiosamus,  175 

Plesiosuchus,  215 

Plestiodon,  162 

Plethodus,  97 

Pleuracanthus,  23 

Pleurocoelus,  236 

Pleurodus,  36 

Plenrolepis,  81 

Pleuroneura,  124 

Pleuropholis,  85 

Pleuroplax,  36 

Pleuroptyx,  126 
j  Pleurosaunis,  151 

Pleurosteriium,  207 

Plicodm,  31 
I  Plioplatecarpiis,  158 
j  Pliosaurus,  177 

Pnigeacanthus,  49 
I  Podocnemis,  205 

Poecilodns,  36 
I  Poikilopleuron,  229 
!  Polacaiithus,  243 
j  Polycotylus,  177 

Polyodon,  74 
I  Polyonax,  244 
'  Polyphractus,  62 
;  Polyplocodus,  71 
;  Polypterus,  73 
!  Polyiitychodon,  178 
!  Polyrhizodus,  39 
i  Polysemia,  137 

Polythorax,  201 
'  Pomognothus,  99 
'  Poiitosaurus,  152 

Porthpus,  95 

Porthochelys,  201 

Priconodon,  243 

Priouodon,  32 
i  Priscacara,  103 
\  Pristacanthus,  49 
\  Pristidadodus,  20 
I  Pristiophorus,  40 
I  Pristis,  40 
,  Pristiurus,  31 
I  Pristodus,  39 
i  Procolophon,  181 

Progauochelys,  204 

Prognathodus,  46 

Prognathosaunis,  158 

Proherodius,  274 

Proiguana,  162 

Prolebias,  100 

Prolepidotv^,  82 

Promyliobatis,  44 

Propelargus,  274 
!  Prophaethon,  275- 
j  Proi)leura,  199 
'  Propristis,  40 

Propterus,  84 

Proterosaurus,  148 

Protobcdistum,  110 
I  Protodus,  20 
1  Protogaleiis,  32 
!  Protosphargis,  198 
i  Protosphyraena,  91 

Protostega,  197 
I  Protriton,  124 
I  Psamvioclielys,  204 
i  Psammodus,  37 
'  Psammolepis,  51 

Psammosteus,  51 
1   Psephoderma,  210 
;  Psephodus,  36 
;  Psephoporus,  197 

Psephurus,  74 

Pseudogaleus,  32 

Pseudosphargis,  198 

Pseudosyngnathiis,  109 

Pseiidothrissops,  90 

Pseudotrionyx,  201 

Psittacus,  277 

Psophia,  273 

Ptenodracon,  253 

Pteranodon,  254 

Pteraspis,  52 
I  Pterwhthyodes,  56 


i  Pterichthys,  56 
I  Pternodus,  23 
1  Pterocletes,  276 

Pterodactylus,  253 
I  Pterycolla^mLnis,  159 

Ptychacanthus,  27 
I  Ptychodus,  43 
I  Ptychogaster,  203 
'  Ptychognathus,  187 
1  Ptycholepis,  84 
j  Ptyctodus,  45 
I  Ptyonius,  126 
i  Ptyonodus,  64 
i  Puppigerus,  198,  199 

Pycnodus,  88 

Pycnosterinx,  104 

Pygopterus,  76 

Python, 164 

Pyxis,  203 

Rachitrema,  228 

Raia,  42 
■  Raiia,  138 
I  Re.dßeldius,  79 
;  Rhäbdoderma,  72 

Rhabdolepis,  77,  94 

Rhacheosaurus,  215 

Rliachitomus,  131 

Rhacolepis,  94 

Rhadincvcanthus,  22 

Rhadinichthys,  76 

Rhainphocephalus,  252 

Rhamphognathus,  108 

Rhamphorhynchus,  253 

Rhamphostoma,  221 

Rhamphosus,  108 

Rhea,  268 

Rhiim,  39 

Rhineastes,  101 

Rhinellus,  99 

Rliiiiemys,  205 

Rhinobatus,  41 

Rhiiiochelys,  205 

Rhinochirnaera,  45 

Rhiuochoetus,  273 

Rhinognathits,  33 

Rhinoptera,  44 

Rhlnosaunis,  157 

Rhizodopsis,  71 

Rhizodus,  70 

Rhodeus,  101 

Rhonialeosaurus,  177 

Rhombus,  102 

Rhopalodoii,  183 

Rhymodus,  37 
I  Rhynchodus,  45 
\  Rhynchosaurus,  150 
1  Rhynchostichus,  220 
I  RhytidGsteus,  134 

Ricnodon,  126 

Rinodus,  45 

Sagenodus,  64 

Sandalodus,  36 
j  Saniva,  162 

Sapheosaurus,  151 
I  Sardinioides,  99 
;  Sardinius,  99 

Sargodon,  82 

Sargus,  105 

Sauraiiodou,  150 

Sauranodon,  171 

Saurichthys,  75 

Sauripterus,  71 

Saurocephalus,  96 
,  Saurodon,  96 

Saurorhaviphus,  9S 

8aurorhynchus,  74 

Scnldia,  39 

Scaniornis,  274 

Scapanorhynchus,  33 

Smphaspis,  52 

Scaphirhynchus,  74 
I  Scaphognathus,  253 

Scaphophis,  165 
I  Scarus,  103 


Scaumenacia,  63 
Scelidosaurus,  242 
Sciiicosaurus,  126 
Sclerocephahis,  129 
Sderodus,  55 
Sclerorliyuchus,  40 
Scoliodoii,  32 
Scomber,  108 
Scorabresox,  103 
Scombroclupea,  9(5 
Scopeloides,  99 
Scyllium,  8l 
Scymnus,  26 
Scytalophis,  165 
Seeleya,  126 
Selache,  35 
Seleuosteus,  61 
Semioiiotus,  80 
Semiophorus,  107 
Sericodon,  214 
Seriola,  108 
Serranus,  105 
Ser  rat  od  US,  39 
Shastasaurus,  171 
Sicarius,  38' 
Simaedosaurus,  150 
Simosaurus,  175 
Siphonostoma,  109 
Smerdis,  105 
Smüodon,  228 
Solea,  102 

Solenorhynchus,  109 
Sparagmites,  129 
Sparnodus,  105 
Spathiurus,  92 
Spiithobatls,  41 
Spathodactylus,  95 
Spatula,  274 
Spatularia,  74 
Sphaerodns,  82 
Sphargis,  197 
Sphenacanthus,  27 
Sphenocephahis,  104 
Sphenodon,  151 
Sphenodus,  33 
Sphenolepis,  100 
Sphenonchus,  28 
Sphenosauriis,  220 
Sphyraena,  108 
Sphyrna,  32 
Spinacorhinvs,  45 
Spiiiax,  26 
Squaloraja,  45 
Squatiua,  39 
Stagoiiolepis,  210 
Staurotypus,  201 
Stegosaurus,  241 
Stemmatias,  23 
Stenimatodus,  23,  88 
Steneosaurns,  214 
Stenosteus,  61 
Stephanodus,  105 
Stereorachis,  149 
Stereosteriiura,  150 
Sternothaerus,  205 
Sterrholophus,  245 
Stethacanthus,  49 
Stigmolepis,  55 
Stratodus,  98 
Streblodus,  36 
Strepsodus,  71 
Streptospondylus,  i229 
Stringops,  272 
Strinsia,  102 
Strobilodus,  83 
Strophodus,  28 
Struthio,  268 
Struthiolithus,  269 
Struthiosaurus,  243 
Stylemys,  203 
Stylemys,  206 
Syllaemus,  108 
Syiiechodus,  29 
Syngnathus,  109 
Synthetodus,  63 
Syodon,  183 


INDEX 


283 


Taeaiodus,  m 

Taeniura,  42 
Tamiobatis,  41 
Tamtodus,  38 
Taniwhasaurus,  159 
Tanystropheus,  231 
Taoperdix,  276 
Taphrosphys,  20ö 
Tapinocephalus,  ISl 
Tauiinichthys,  103 
Teleidosaiirus,  '214 
TeleosauruH,  214 
Telerpeton,  14S 
Teracus,  27*3 
Terata'iaurtis,  228 
Testudo,  203 
Tetragonolepis,  81 
Tetrao,  276 
Thalassemvs,  20U 
Thalassochelys,  198 
Tharsis,  98 
TJmwmas,  39 
Thaw^iatosaurus,  177 
Thecodöntosaurus,  228 
Thecospondylus,  231 
Thectodus,  28 
Thelodus,  51 
TheloUpis,  51 
Theriodesinus,  184 
Theriognathus,  187 
Thei-iosuchns,  217 


Theropleura,  149 
■Thespesnos,  240 
Tholodus,  81 
Thoracosaurus,  220 
Thrinacodus,  23 
Thrissonotns,  77 
Thrissopater,  94 
Thrissops,  94 
Thursius,  71 
Thyellina,  31 
Thyestes,  55 
Thynuichthys,  101 
Thynnus,  lOS 
Tigrisuchus,  ISo 
Tinainns,  271 
Tinea,  101 
Tinosaurus,  162 
Titanichthys,  60 
Titanophis,  165 
Titanosaurus,  236 
Titanosuchiis,  187 
Tomistoina,  220 
Torosaurus,  245 
Torpedo,  42 
Toxochelys,  201 
Trachinotus,  108 
Trachodon,  240 
Trachosteus,  61 
Trachyaspis,  201 
Traqiiairitt,  21 
Treinataspi.s,  55 


I  Treiriatosaurus,  132 
I  Tretosternuin,  201 

Triacis,  32 
'  Trkieniupis,  98 
i  Triaenodon,  32 
,  Triceratops,  244 
I  Trichiurichthys,  107 
i  Triglochis,  33 
!  Triglyphus,  184 
'  Trigonodon,  105 

Trigonodus,  36,  39 

Trimerorachis,  130 
j  Trinacroinennn,  177 

Triodus,  23 

Trionyx,  196 

TriplopUrus,  71 
I  Tripterus,  71 
i  Trirachodon,  184 
t  Tristichopterus,  71 
!  Tristychius,  27 
:  Triton,  137 

Tritylodon,  184 
i  Trogon,  277 

Tropidemys,  200 

Trygon,  42 
]  lYygonohatus,  42 
t  Trygonorhina,  41 

Tuditanus,  126 
;  T^irin'm,  51 
,  Tylosaurus,  157 
I  Typothorax,  211 


Undina,  72 

Unitornis,  27V 
Uraeus,  83 
!  Urenchelys,  101 
j  Urocordyhis,  12(i 
Urolophus,  42 
Uronaiites,  177 
Uronemus,  tf 
Urosphen,  lOs 

Vaticinodus,  36 

Vomer,  10« 

Wardichthys,  78 

Weisslit,  129 
Wodiiika,  48 

XenacanthuSf  22 

Xestops,  1(>2 
Xipharttinvii,  95 
Xiphotrygon,  42 

I  Xystracanthiis,  49 
I  Xystrodus,  36 

Zanclodon,  228 
I  Zanclus,  107 

Zatrachis,  131 

Zenaspis,  54 
I  Zygaena,  32 
j  Zygöbates,  44 
I  Zygosaurus,  130 


END   OF   VOL.    II 


Printedby  R.  &  R  Clark,  Limited,  Edinburgh. 


Folume  I.     Medium  8vo.     255.  net      IFith  1476  Woodcuis. 

TEXT-BOOK  OF  PALAEONTOLOGY 

By  KARL  A.  VON  ZITTEL, 

Professor  of  Geology  and  Palaeontology  in  the  University  of  Munich. 
TRANSLATED    AND    EDITED    BY 

CHAELES    E.   EASTMAN,  Ph.D, 

Assistant  in  Palaeontology  in  tlie  Museum  of  Comparative  Zoology 
at  Harvard  College,  Cambridge,  Mass. 

English  Edition  Eevised  and  Enlarged  by  the  Author  and  Editor  in 
CoUaboration  with  the  foUowing  Specialists :  C.  E.  Beecher,  J.  M. 
Clarke,  W.  H.  Dall,  G.  J.  Hinde,  A.  Hyatt,  J.  S.  Kingsley,  H.  A. 

PiLSBRY,  C.  SCHÜCHERT,  S.  H.  SCÜDDER,  W.  P.  SlADEN,  E.  0.  ULRICH, 

C.  Wachsmuth. 

SPEAKER. — "  In  this  sphere  Professor  Zittel's  books  have  long  held  the 
field  as  the  Standard  works  of  their  class,  but  to  many  they  have  been  inaccessible 
on  account  of  their  being  in  a  foreign  tongue.  .  .  .  It  has  not  merely  been 
translated  ;  it  has  been  edited  and  brought  up  to  date  as  well.  .  .  .  The  author 
and  editor  have  conferred  a  great  boon  upon  their  fellow-workers,  whether 
English  or  foreign,  by  bringing  out  what  is  really  a  new  edition  of  this  work. 
.  .  .  A  most  valuable  addition  to  the  scientific  literature  of  the  world,  and  the 
publication  of  the  second  volume,  dealing  ^vith  the  vertebrata,  will  be  awaited 
with  the  keenest  interest  on  all  sides." 

FIELD. — "An  admirable  introduction  to  the  study  of  those  fossils  or 
petrified  organic  remains  of  plants  and  animals  which  existed  before  the  präsent 
geological  period  and  the  advent  of  man  on  the  face  of  the  globe.  .  .  .  Will  be 
of  the  greatest  possible  assistance  to  all  geological  students.  .  .  .  Too  much 
praise  cannot  be  bestOwed  on  the  accuracy  and  beauty  of  the  illustrations." 

MACMILLAN  AND  CO.,  Ltd.,  LONDON. 


THE   CAMBRIDGE    NATURAL    HISTORY 

Edited  by  S.  F.  Harmer,  Sc.D.,  F.R.S.,  Fellow  of  King's  College,  Cambridge, 
Superintendent  of  the  University  Museum  of  Zoology,  and  A.  E.  Shipley, 
M.A.,  Fellow  of  Chris t's  College,  Cambridge,  University  Lecturer  on  the 
Morphology  of  Invertebrates. 

To  he  completed  in  Ten.  Volumes.      Svo.     Frice  175.  net  euch. 

The  following  Volumes  are  ready  :— 

WORMS,   LEECHES,   ETC. 

VOLUME  II 

Second  Impression 

Fiat  Worms.  By  F.  W,  Gamble,  M.Sc.Yict.,  Owens  College.— Nemertines.  By  Miss 
L.  Sheldon,  Newnham  College,  Cambridge. — Thread-worms,  etc.  By  A.  E.  Shipley, 
M.A.,  Fellow  of  Christ's  College,  Cambridge. — Rotifers.  By  Marcus  Hahtog,  M.A., 
Trinity  College,  Cambridge,  D.Sc.Lond.,  Professor  of  Natural  History  in  the  Queen's 
College,  Cork. — Polychaet  Worms.  By  W.  Blaxland  Benham,  D. Sc,  Hon.  M.  A.  Oxon., 
Professor  of  Biology  in  the  University  of  Otago. — Earth-worms  and  Leeches.  By 
F.  E.  Beddard,  M.A.  Oxon.,  F.R.S.,  Prosector  of  the  Zoological  Society,  London.— 
Gephyreä,  etc.  By  A.  E.  Shipley,  M.A. 
Polyzoa.     By  S.  F.  Harmer,  Sc.D.,  F.R.S.^ 

SHELLS 

VOLUME  III 
MoUuscs  and  Brachiopods 

By  the  Rev.  A.  H.  Cooke,  M.A.,  A.  E.  Shipley,  M.A.,  and  F.  R.  C.  Reed,  M.A. 

TIMES. —  "There  are  very  many,  not  only  among  educated  people  who  take  an  interest 
in  science,  but-  even  among  specialists,  who  will  welcome  a  work  of  reasonable  compass 
and  handy  form  containing  a  trustworthy  treatment  of  the  various  departments  of  N^atural 
History  by  men  who  are  familiär  with,  and  competent  to  deal  with,  the  latest  results  of 
scientific  research.  Altogether,  to  judge  from  this  first  volume,  the  Cambridge  Xatural  History 
promises  to  fnlfil  all  the  expectations  that  its  prospectus  holds  out." 

INSECTS   AND   CENTIPEDES 

VOLUME  V 

Second  Impression 

Peripatus.     By  Adam  Seduwick,  ^l.A.,  F.R.S. — Myriapods.     By  F.  G.  Sinclair,  M.A. — 
Insects.     Part  I.    By  David  Sharp,  M.A.  Cantab.,  M.B.  Edin.,  F.R.S. 

FIELD. — "  Although  written  for  the  student  and  the  specialist,  the  book  is  not  the  less 
adapted  to  all  intelligent  readers  who  wish  to  make  themselves  thoroughly  acquainted  with  the 
habits,  structure,  and  the  modern  Classification  of  the  animals  of  which  it  treats.  To  .such  it 
cannot  be  recommended  too  strongly." 

ENTOMOLOGIST S  MONTHLY  MAGAZINE.— ''We  venture  to  think  the  work  ^yiIl 
be  found  indispensable  to  all  who  seek  to  exteud  their  general  knowledge  beyond  the  narrowing 
inrinence  of  exclusive  attention  to  certain  orders  or  groujts,  and  that  it  will  take  a  high  position 
in  '  The  Cambridge  Natural  History'  series." 


INSECTS— Part  U 

VOLUME  VI 
Second  Impression 
Uymenoptera  CO lUimicd  (Tubuliferaand  Aculeata),  Coleoptera,  Strepsiptera,  Lepidoptera, 
Diptera,  Aphaniptera,  Thysanoptera.  Hemiptera,  Anoplura.     ßv  DavikSh  viti-  M  \' 
M.B.,  F.K.S.  ^  ^'    — » 

SATURDAF  IlI!FI£lJF.  —  "Mv.  Sliarp's  treatment  is  altogether  worthy  of  the  series  and 
of  bis  own  high  scientific  reputation.  But  in  a  work  of  this  sort  it  is  not  only  necessary  that 
infoiinatiou  sliould  be  accurate,  bnt  also  that  itshall  be  presented  tothe  eye,  so  faras  illustra- 
tions  and  printing  are  coneerned,  in  such  a  way  as  to  render  its  matter  as  easily  intellicrible 
as  possible,  and  readily  usable  for  purposes  of  reference.  Under  both  these  heads  \\e  have 
nothing  but  comniendation  for  Mr.  Sharp's  treatise.  The  illustrations  are  indeed  ])eautiful, 
and  the  use  of  the  heavy  type  for  the  headings  of  the  various  sections  and  leading  jiaragraplis 
niatorially  helps  the  readcr  in  the  ])rogress  of  his  study,  Certainly  this  is  a  book  tliat  should 
be  in  every  entomologist's  library." 

AMPHIBIA  AND   REPTILES 

VOLUME  VIII 
By  Hans  Gadow,  M.A.,  Ph.D.,  F.K.S. 

FIELD.  —  "The  work  is  worthy  of  the  series  in  which  it  appears,  and  we  eannot  give  it 
higher  praise." 

SCIENCE  GOSSIF.  —  "More  than  maintains  the  high  scientific  reputation  of  tliis  series. 
The  herpetologists,  or  students  of  the  Amphibia  and  Reptiles,  have  now  a  Standard  work  of  tlie 
highest  class." 

BIRDS 

VOLUjNIE  IX. — Second  Impression 
By  A.  H.  Evans,  M.  A.,  Cläre  College,  Cambridge.  With  numerous  Illustrations  by  G.  E.  Lodge. 

IBIS. —  "Mr.  Evans  has  produced  a  book  füll  of  concentrated  essence  of  information  on  birds, 
especially  asregards  their  outer  structure  and  habits,  and  one  that  we  can  cordially  recomniend 
as  a  work  of  reference  to  all  students  of  ornithology." 

MAMMALIA 

VOLUME  X 
By  F.  E.  Beodahd,  M.A.  Oxon.,  F.R.S.,  Prosector  of  the  Zoological  Society. 

NATURE.  — "  Cannot  fail  to  be  of  very  high  value  to  all  students  of  the  Älammalia, 
especially  froni  the  standpoints  of  niorphology  and  palaeontology." 

AT  KEN  JEU M.  — "  Mr.  Beddard  has  produced  a  volume  equal  in  interest  and  value  to  the 
others  in  the  Cambridge  series." 

The  foUowing  volumes  which  are  in  the  Press  or  in  active  preparation  will  complete 

the  series : — 

A^OLUME  I 

Protozoa,  MARcrs  Hartog,  M.A.,  D.Sc,  Trinity  College  (Professor  of  Natural  History  in 
the  Queen's  College,  Cork);  Sponges,  W.  J.  Sollas,  Sc.D.,  F.R.S.,  St.  John's  College 
(Professor  of  Geology  in  the  University  of  Oxford)  ;  Jelly-fish,  Sea-Anemones,  etc.,  S.  J. 
HiCKSON,  M.A.,  F.R.S.,  Dowiiing  College  (Beyer  Professor  of  Zoology  in  The  Owens  College, 
Manchester)  ;  Star-fish,  Sea-Urchins,  etc.,  K.  W.  MacBuide,  M.A.,  St.  John's  College 
(Professor  of  Zoology,  McGill  University,  Montreal).  [In  active prejmi'ation. 

VOLUME  IV 

Spiders,  Mites,  etc.,  C.  Waubuhton,  M.A.,  Chri.st's  College  (Zoologist  to  the  Royal 
Agricultural  Society) ;  Scorpions,  Trilobites,  etc.,  M.  Lauüie,  B.A.,  King's  College, 
D.Sc.  Edinb.  ( Professor  of  Zoology  in  St.  Mungo's  College.  Glasgow);  Pycnogonids,  etc., 
D'AiiCY  AV.  Thompson,  C.B.,  M.A.,  Trinity  College  (Professor  of  Zoology  in  University 
College,  Dundee)  ;  Crustacea,  W.  F.  R.  Wf.ldox,  M.A.,  F.R.S.,  St.  John's  College  (Linacre 
Professor  of  Comparative  Anatomy  in  the  University  of  Oxford).         [In  active  preparafioii. 

VOLUME  VII 

Balanoglossus.etc,  S.  F.  Haumeu,  Sc.D.,  F.R.S.,  King's  College  ;  Ascidians  and  Amphioxus, 
W.  A.  Heim)Man.  D.Sc.  Lond.,  F.R.8.  (Prolessor  of  Natural  History  in  Univer.sity  College, 
Liverpool);  Fishes,  T.  W.  Bimdoe,  Sc.D.,  Trinity  College  (Professor  of  Zoology  in  Birming- 
ham University),  and  G.  A.  Boulengeu,  F.R.S.  [In  the  Press. 

MACMILLAN  AND  CO.,  Ltd.,  LONDON. 


WORKS    ON    ZOOLOGY. 

THE  FOUNDATIONS  OF  ZOOLOGY.  By  William  Keith  Brooks,  Ph.D., 
LL.D.     8vo.      10s.  6d.  net. 

AN  INTRODÜCTION  TO  THE  OSTEOLOGY  OF  THE  MAMMALIA. 
By  Sir  William  Henry  Flower,  F.K.S.  Illustrated.  Third  Edition. 
Revised  with  the  assistance  of  Hans  Gadow,  Ph.D.     Crown  8vo.    10s.  Gd. 

TEXT-BOOK  OF  COMPARATIVE  ANATOMY.  By  Dr.  Arnold  Lang. 
With  Preface  to  the  English  Translation  by  Professor  Dr.  Ernst  Haeckel. 
Translated  by  H.  M.  and  M.  Bernard.  Illustrated.  Two  volumes.  Svo. 
17  s.  het  each.  ^ 

A  COURSE  OF  INSTRUCTION  IN  ZOOTOMY  (Vertebrata).  By  T. 
Jeffrey  Parker,  B.Sc,  F.R.S.     Illustrated.     Crown  Svo.     8s.  6d. 

ELEMENTS  OF  THE  COMPARATIVE  ANATOMY  OF  VERTEBRATES. 
Adapted  by  W.  Newton  Parker  from  the  German  of  Robert  Wieders- 
jieim,  Professor  of  Anatomy,  and  Director  of  the  Institute  of  Human  and 
Comparative  Anatomy  in  the  University  of  Freiburg,  in  Baden.  Illustrated. 
Svo.      12s.  6d.  net. 

THE  PROTOZOA.     By  Gary  N.  Calkins,  Ph.D.     Svo.     12s.  6d,  net. 

NATURAL  HISTORY  OF  MARKETABLE  MARINE  FISHES.     By  J.  T. 

Cunningham.     Svo.     7s.  6d.  net. 

EXPERIMENTAL  MORPHOLOGY.  By  Charles  Benedict  Davenport, 
Ph.D.,  Instructor  in  Zoology  in  Harvard  University.  Part  I.  Svo.  9s.  net. 
Part  IL  Effect  of  Chemical  and  Physical  Agents  upon  Growth.  Svo. 
9s.  net. 

INTRODÜCTION  TO  ZOOLOGY.  By  Prof.  C.  B.  Davenport,  Ph.D.,  and 
Gertrude  C.  Davenport.     Crown  Svo.     6s. 

AN  ATLAS  OF  PRACTICAL  ELEMENTARY  ZOOTOMY.  By  G.  B. 
Howes,  LL.D.,  Professor  of  Zoology,  Royal  College  of  Science,  London. 
With  a  Preface  by  Professor  Huxley.      4to.      10s.  net. 

A  COURSE  OF  ELEMENTARY  INSTRUCTION  IN  PRACTICAL 
BIOLOGY.  By  T.  H.  Huxley,  F.R.S.,  and  H.  N.  Martin.  Revised  and 
extended  by  Professor  G.  B.  Howes  and  D.  H.  Scott,  Ph.D.  Crown  Svo. 
10s.  6d. 

ELEMENTARY  PRACTICAL  ZOOLOGY.  By  the  late  Professor  T.  J. 
Parker,  F.R.S.,  and  Professor  W.  Newton  Parker.  Illustrated.  Crown 
Svo.     10s.  6d. 

A  MANUAL  OF  ZOOLOGY.  By  the  late  Professor  T.  J.  Parker,  F.R.S., 
Professor  of  Biology  in  the  University  of  Otago,  Dunedin,  N.Z.,  and 
Professor  W.  A.  Haswell,  F.R.S.,  Professor  of  Biology  in  the  University 
of  Sydney,  N.S.W.     Crown  Svo.     10s.  6d. 

A  TEXT-BOOK  OF  ZOOLOGY.  By  the  late  Professor  T.  J.  Parker,  F.R.S., 
and  Professor  W.  A.  Haswell,  F.R.S.  Illustrated.  Two  vols.  Medium 
Svo.      36s.  net. 

MACMILLAN  AND  CO.,  Ltd.,  LONDON. 

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