362 
VARIETIES. 
fated  forms  which  fancy  had  conjured  up  have  vanished  :  and  around,  on 
every  side,  is  bleak  and  barren  desolation. 
Then,  too,  if  the  exploration  be  made  in  midsummer,  the  scorching  rays 
of  the  sun,  pouring  down  in  the  hundred  defiles  that  conduct  the  wayfarer 
through  this  pathless  waste,  are  reflected  back  from  the  white  or  ash-colored 
walls  that  rise  around,  unmitigated  by  a  breath  of  air,  or  the  shelter  of  a 
solitary  shrub. 
The  drooping  spirits  of  the  scorched  explorer  are  not  permitted,  however, 
to  flag.  The  fossil  treasures  of  the  way,  well  repay  its  sultriness  and  fa- 
tigue. At  every  step,  objects  of  the  highest  interest  present  themselves. 
Embedded  in  the  debris,  lie  strewn,  in  the  greatest  profusion,  organic  relics 
of  extinct  animals.  All  speak  of  a  vast  fresh- water  deposit  of  the  early 
Tertiary  Period,  and  disclose  the  former  existence  of  most  remarkable  races, 
that  roamed  about  in  bygone  ages  high  up  in  the  Valley  of  the  Missouri, 
towards  the  sources  of  its  western  tributaries  ;  where  now  pastures  the  big- 
horned  Ovis  montana,  the  shaggy  buffalo  or  American  bison,  and  the  ele- 
gant and  slenderly  constructed  antelope. 
Every  specimen  as  yet  brought  from  the  Bad  Lands,  proves  to  be  of  species 
that  became  extirminated  before  the  mammoth  and  mastodon  lived,  and 
which  differ  in  their  specific  character,  not  alone  from  all  living  animals, 
but  also  from  all  fossils  obtained  even  from  cotemporaneous  geological 
formations  elsewhere. 
Along  with  a  single  existing  genus,  the  Rhinoceros,  many  new  genera 
never  before  known  to  science  have  been  discovered,  and  some,  to  us  at  this 
day,  anomalous  families,  which  combine  in  their  anatomy,  structures  now 
found  only  in  different  orders.  They  form,  indeed,  connecting  links  be- 
tween the  pachyderms,  plantigrades  and  digitigrades.  For  example,  in  one 
of  the  specimens  from  this  strange  locality,  described  by  Dr.  Leidy  under 
the  name  of  ArcliceoiJierium,  we  find  united  characters  belonging  now  to 
the  above  three  orders ;  for  the  molar  teeth  are  constructed  after  the  model 
of  those  of  the  hog,  peccary  and  babyroussa  ;  the  canines  as  in  the  bear  ; 
while  the  upper  part  of  the  scull,  the  cheek  bones,  and  the  temporal  fossa 
assume  the  form  and  dimensions  which  belong  to  the  cat  tribe.  Another, 
the  Greodon  of  Leidy,  has  grinding  teeth  like  the  elk  and  deer,  with  canines 
resembling  the  omnivorous  thick-skinned  animals  ;  being,  in  fact,  a  race 
which  lived  both  on  flesh  and  vegetables,  and  yet  chewed  the  cud  like  our 
cloven-footed  grazers. 
Associated  with  these  extinct  races,  we  beheld  also,  in  the  Mauvaises 
Terres,  abundant  remains  of  fossil  pachydermata,  of  gigantic  dimensions, 
and  allied  in  their  anatomy  to  that  singular  family  of  proboscidean  animals, 
of  which  the  tapir  may  be  taken  as  a  living  type.  These  form  a  connecting 
link  between  the  tapir  and  the  rhinoceros  ;  while,  in  the  structure  of  their 
grinders,  they  are  intermediate  between  the  daman  and  rhinoceros ;  by 
their  canines  and  incisors,  they  connect  the  tapir  with  the  horse,  on  the  one 
hand,  and  with  the  peccary  and  hog  on  the  other.  They  belong  to  the  same 
