44 
MISS  OGILVIE  OH  THE  WENGEN  AND  [Feb.  1 893, 
exposed  within  the  district  of  Enneherg  and  Ampezzo.  These 
are : — 
Ostrcea  moniis-caprilis,  Klipst. 
Gervillia  Bouei,  Hauer. 
Hoernesia  Johannis- Austria,  Klipst. 
Myophoria  jissidentata,  Wohrm. 
- Kefersteini,  Klipst. 
Trigonodus  rablensis,  Gredler,  sp. 
Fimbria  (C orb  is)  Mellingi,  Hauer,  sp. 
Megalodon,  sp.  indet. 
Megalodon,  cf.  complanatus, 
Wohrm. 
Placwiopsis,  sp.  indet. 
Halobia  rugosa,  Gumbel. 
Thecospira  Gumbeli,  Pichler,  sp. 
Cidaris  Braunii,  Desor. 
Fentacrinus  tirolensis,  Laube. 
On  the  western  slopes  of  the  Diirrenstein,  a  hed  of  lithodendroid 
coral-limestone  occurs,  and  may  be  followed  for  some  distance 
between  the  thinly-bedded  doiomitic  flags  belonging  to  the  Raibl 
series. 
In  considering  the  list  of  Wengen  and  St.  Cassian  fossils,  the 
extreme  faunal  poverty  of  the  ashy  Wengen  strata  calls  for 
remark.  Species  of  Halobia  and  Posidonomya  frequently  occur, 
but  in  addition  to  these  I  found  only  a  few  ammonites,  the 
majority,  unfortunately,  too  badly  preserved  for  identification. 
There  are,  among  the  345  species  of  St.  Cassian  fossils  found,  23 
sponges,  51  corals,  30  echinoderms,  32  brachiopods,  62  lamelli- 
branchs,  121  gasteropods,  26  nautiloid  and  ammonite  forms,  together 
with  a  number  of  poiyzoa.  The  great  preponderance  of  gasteropods, 
of  which  only  about  10  per  cent,  continue  into  the  Raibl  period, 
is  very  striking,  and  they  indeed  give  a  quite  peculiar  stamp  to 
the  St.  Cassian  fauna.  The  brachiopods  are  mostly  peculiar  to 
Middle  and  Upper  St.  Cassian  strata  ;  the  number  present  in  Lower 
St.  Cassian  or  in  Raibl  Beds  being  extremely  limited. 
The  following  table  shows  the  percentages  of  St.  Cassian  species 
which  occur  at  all  the  horizons  in  the  list  on  pp.  48  et  seqq. 
Percentage  Table. 
■ 
N.  Tyrol. 
Enneberg  and  Ampezzo. 
N.  &  S.  Alps. 
Partnacb 
Strata. 
Wengen 
Strata. 
St.  Cassian. 
Raibl. 
Lower. 
Middle. 
Upper. 
Lower. 
Upper. 
Corals  . 
0 
0 
8 
74-5 
66-6 
6 
0 
Echinoderms  . 
26-6 
6-6 
26-6 
86-6 
636 
30 
16-6 
Brachiopods  . 
21-8 
0 
3*1 
78T 
34-3 
3 
0 
Lamellibranchs . 
6-4 
5 
6-4 
64-5 
54-8 
38-7 
17-7 
Gasteropods  . 
0 
0 
0 
77-6 
45-4 
74 
0-8 
Naut.  and  Amm.  sp. 
7*7 
? 
11*5 
80-7 
15-3 
19-2 
0 
A  few  typical  Wengen  fossils  still  continue  in  the  Lower  St.  Cas¬ 
sian  zone,  which  I  identify  with  the  first  bed  of  Cipit  Limestone 
on  the  Seisser  Alpe.  In  this  zone  the  first  significant  beginning  of 
the  St.  Cassian  fauna  occurs ;  the  fauna  reaches  its  maximum 
development  in  Middle  St.  Cassian  time  ;  still  continues  strongly 
marked  in  Upper  St.  Cassian  time;  dwindles  gradually, or  sporadic- 
