Yol.  49.] 
ST.  CAS  SI  AX  STRATA  IX  SOUTHERX  TYROL. 
11 
nature  of  the  Upper  Triassic  rocks.  He  differed  from  Richt¬ 
hofen  in  assuming  that  the  coral-reefs  began  to  form  in  certain 
localities  directly  after  the  deposition  of  the  Muschelkalk  strata. 
A  case  in  point  is  offered  by  the  dolomite-rock  of  the  Schlern 
mountains.  Referring  to  Richthofen's  section  (op.  jam  cit.  pp.  40- 
43)  this  rock  is  regarded  as  a  reef  built  on  a  subsiding  portion 
of  Muschelkalk  rock  after  the  period  of  the  deposition  of  the 
Buchenstein  and  Wengen  Beds  exposed  on  the  Seisser  Alpe.  The 
highest  beds  exposed  on  the  Seisser  Alpe  contain  a  St.  Cassian 
fauna,  and  these  are  the  beds  regarded  by  Richthofen  as  the 
time-equivalent  of  the  dolomite-reef  in  part ;  he  further  believed 
that  the  reefs  continued  to  grow  after  the  St.  Cassian  period,  and 
that  Raibl  Beds  and  a  Raibl  fauna  spread  themselves  then  irregu¬ 
larly  above  the  reefs  and  above  the  St.  Cassian  Beds  in  the  channels 
beyond.  The  name  of *  4  Schlern  Dolomite  ’  was  given  by  Richthofen 
to  the  dolomitic  rock  developed  within  these  ages. 
Richthofen’s  idea  that  after  Muschelkalk  time  a  gradual  uprising 
of  the  rock,  followed  by  subsidence,  took  place  in  the  Schlern 
district  and  farther  south,  was  not  accepted  by  Mojsisovics,  who 
held  that  the  reefs  grew  upon  the  Muschelkalk  during  the  depo¬ 
sition  of  the  whole  series  of  Buchenstein,  lYengen,  and  St.  Cassian 
sedimentary  beds.  Mojsisovics,  therefore,  gave  up  the  name  of 
‘  Schlern  Dolomite/  and  introduced  names  for  the  dolomitic  horizons 
in  correspondence  with  the  names  of  the  non-dolomitic  beds.  The 
alteration  thus  introduced  by  him  may  be  represented  as  follows  : — 
Richthofen’s  Succession. 
r  Raibl  Beds. 
^  Raibl  Beds. 
*5i 
(  Schlern 
Schlern 
0 
0 
0 
Dolomite. 
< 
Dolomite. 
m 
®  ■< 
St.  Cassian 
1 
.0 
Beds. 
(Unconfor-’ 
0 
VVengen  Reds. 
mity.) 
0 
0 
Buchenstein 
^  Beds. 
Muschelkalk  (Mendola  Dolomite). 
Mojsisovics’  Succession. 
Raibl  Beds. 
(  St.  Cassian 
(  St.  Cassian 
Beds. 
. 
m 
O 
Dolomite. 
ft 
■{  VV  engen 
|  • 
J5 
0 
Wengen 
Beds. 
Dolomite. 
Buchenstein 
ft 
Buchenstein 
^  Beds. 
^  Dolomite. 
Muschelkalk. 
Many  cases  are  quoted  by  Mojsisovics  as  affording  proof  of  the 
4  heteropism  ’  of  the  strata,  either  by  the  thinning-out  of  the  zones 
of  sedimentary  beds  in  the  dolomitic  facies,  or  bv  the  conformable 
succession  of  the  Raibl  Beds,  sometimes  on  the  dolomitic,  sometimes 
on  the  non-dolomitic  facies  of  the  St.  Cassian  horizon. 
