Yol.  49.] 
HORNBLENDE  FROM  THE  BINNENTHAL. 
105 
excavated.  This  group,  the  highest  in  position  among  the  crys- 
talline  rocks  of  the  Alps,  practically  extends,  as  I  have  already 
stated,1  from  one  end  of  the  chain  to  the  other.  Its  members 
are  usually  more  or  less  calcareous,  though  quartz-schists  occur ; 
mica  is  almost  invariably  present,  but  occasionally  the  rock  becomes 
a  marble,  practically  a  crystalline  mass  of  calcite  or  dolomite. 
Chloritic  and  hornblendic  schists  also  occur,  but  some  of  these  are 
certainly  modified  intrusions,  though  others  may  have  been  originally 
interstratified  tuffs.  These  dark-mica  schists  are  not  seldom  inter- 
banded  with  impure  quartzite  or  quartz-schists,  just  as  argillaceous 
and  arenaceous  layers  are  associated  in  the  Palseozoic  rocks  of  the 
Isle  of  Man  or  of  Morlaix,2  or  in  other  cases  of  sediment  too 
numerous  to  mention,  even  down  to  the  stratified  drifts  at  Cromer. 
Not  unfrequently,  as  I  have  noted  in  previous  papers,3  these 
dark-mica  schists  contain  garnets,  from  the  size  of  a  small  cherry 
downwards.  I  have  found  them  myself  at  intervals  from  the 
southern  slopes  of  the  Lukmanier  Pass  to  near  Binn,  a  distance  of 
over  thirty  miles  in  a  straight  line.  In  places,  as  in  the  crags  at 
the  head  of  the  Iiitom  Boden  (Yal  Piora),  on  the  Nufenenstock, 
or  in  the  ridges  about  the  Gries  Glacier,  these  garnet-bearing 
schists  are  of  no  small  thickness,  but  there  are  considerable  intervals 
in  which  I  have  not  met  with  that  mineral,  and  I  have  not  yet 
found  it  on  the  Simplon  Pass  4  or  in  the  Yispthal. 
Por  a  description  of  the  structure,  macroscopic  and  microscopic, 
of  these  garnet-bearing  rocks  and  other  associated  schists,  I  may 
refer  to  my  paper,  already  printed  in  this  Journal,5  and  to  an  elaborate 
investigation  by  Dr.  Grubenmann,6  frequently  quoted  therein. 
The  specimen  now  to  be  noticed  was  collected  by  Mr.  J.  Eccles, 
in  the  summer  of  1890,  from  the  outcrop  in  the  bed  of  the  torrent 
above  the  village  of  Binn.7  Above  it  are  schists  of  the  4  Pian 
Alto  ’  type,  which  become,  somewhat  higher  up,  distinctly  calcareous. 
They  are  overlain  by  the  white  dolomite,  mentioned  in  my  former 
paper  (p.  211). 
This  specimen  (a  slab  about  *5  inch  thick)  differs  little  from 
those  collected  by  myself  in  other  localities.  The  upper  and  under 
surfaces  are  due  to  cleavage-foliation  ;  the  lustre  perhaps  is  slightly 
more  silvery  than  it  is  in  some  of  my  own  specimens,  where  it  more 
resembles  that  of  graphite.  Evidently  it  is  due  to  a  continuous 
1  Quart.  Journ.  Geol.  Soc.  vol.  xlvi.  (1890)  p.  187. 
2  Ibid.  vol.  xliv.  (1888)  p.  11. 
3  Ibid.  vol.  xlii.  (1886)  JProc.  pp.  72-75  ;  ibid.  vol.  xlvi.  (1890)  pp.  202-3, 
224-8. 
4  It  has,  however,  been  found  by  Mr.  J.  Eccles  not  far  away  to  the  east,  and 
on  the  southern  side  of  the  watershed. 
5  Vol.  xlvi.  (1890)  pp.  199-204,  208-210,  224-229. 
6  Mitt,  der  Thurg.  naturf.  Gesellsch.  1888,  Heft  viii. 
7  We  discovered  the  rock  in  1889,  but,  being  quite  satisfied  as  to  its  nature, 
we  did  not  bring  away  a  specimen,  for  some  scrambling  would  have  been 
required  to  get  it,  and  we  had  done  more  than  an  eight  hours’  day.  But  as  we 
did  not  find  this  particular  rock  farther  east,  I  asked  Mr.  Eccles,  in  1890, 
to  be  so  good  as  to  bring  back  a  specimen. 
