Yol.  49.] 
ST.  CASSIAN  STRATA  IN  SOUTHERN  TYROL. 
43 
fossiliferous  Eaibl  horizon  which  I  have  mentioned  in  the  above 
sections,  one  must  conclude  that  the  Schlern-plateau  Beds  are  still 
older.  The  Eaibl  Beds  of  Southern  Tyrol  fall  into  the  following 
sub-groups : — 
(  Variegated  marls  and  Megalodon- bearing  dolomitic  flags, 
j  0sfr«a-limestone  '\ 
Eaibl  Beds.  ■{  Mgophoria-limestone  [  passing  into  a  dolomitic 
j  Schlern-plateau  strata,  and  dolomitic  f  facies. 
(  encrinite-  or  coral-limestone  J 
8.  The  Dachstein  Dolomite. — The  Dachstein  Dolomite  is  the 
highest  subdivision  of  the  Triassic  system  in  Southern  Tyrol.  It  is 
a  continuous  development  of  dolomite  and  dolomitic  limestone  several 
thousand  feet  thick  ;  and  since  it  lies  conformably  above  the  Eaibl 
Beds  and  below  the  Liassic  strata  it  is  the  representative,  in  the 
Southern  Tyrol  Dolomites,  of  the  ‘  Hauptdolomit  ’  Kossen  Beds,  and 
the  Dachstein  Limestone  of  Northern  Tyrol. 
The  rock  is  a  crystalline  dolomite,  generally  greyish-white  in 
colour,  but  sometimes  reddish.  It  is  always  well  stratified,  and 
may  be  either  of  compact  or  drusy  structure.  Fossils  occur  commonly 
enough,  although  in  small  variety.  The  typical  fossil  Megalodon 
triquetei',  Wulf.,  is  common  also  in  the  Dachstein  Kalk  of  Fort-hern 
Tyrol.  Specimens  of  a  very  large  Megalodon  occur  sometimes  in 
great  number  in  the  Dachstein  Dolomite  of  Tofana. 
YII.  Palaeontological  Conclusions. 
The  first  nine  columns  of  the  List  of  Fossils  (pp.  48  et  seqq.), 
containing  345  species,  include  the  various  localities  in  Enneberg 
and  Ampezzo  where  I  worked.  The  tenth  column,  referring  to 
Partnach  Beds,  etc.,  is  introduced  only  to  show  the  particular  species 
in  this  list  which  are  already  known  to  occur  elsewhere  in  other 
strata.  The  fauna  of  the  Partnach  Beds  in  Forthern  Tyrol  is  com- 
paratively  meagre,  about  half  the  known  species  being  identical  with 
St.  Cassian  and  Wengen  species  in  Southern  Tyrol.  On  the  other 
hand,  only  about  6  per  cent,  of  the  fossils  given  in  the  TTengen  and 
St.  Cassian  horizons  in  the  list  have  been  found  in  Partnach  strata. 
Comparing  then  the  tenth  column  with  the  others,  we  find  that 
16*5  per  cent,  of  the  St.  Cassian  species  occur  also  in  Eaibl  Beds 
(including  all  the  districts  referred  to).  The  faunal  relations  of 
the  two  series  of  Fpper  Triassic  strata  are  readily  seen  from  the 
following  percentages  : — Of  St.  Cassian  sponges  13  per  cent,  are 
present  in  Eaibl  strata,  of  corals  5‘9  per  cent.,  of  echinoderms 
33’3  per  cent.,  of  brachiopods  3  per  cent.,  of  lamellibranchs  40*3 
per  cent.,  of  gasteropods  8*2  per  cent.,  of  nautiloid  and  ammonite 
forms  19 ‘2  per  cent. 
The  writer  collected  also  a  number  of  fossils  in  the  Eaibl  strata 
