Yol.  49.] 
OF  THE  SHERBORNE  DISTRICT. 
517 
accuracy — at  least  in  the  strata  known  as  ‘  Sands  and  Cephalopoda- 
bed’;  because  the  beds  are  thin,  and  it  is  possible  to  excavate 
them  with  the  hammer  at  any  time.  In  Dorset,  to  work  the  quarries, 
men  with  heavy  tools  and  gunpowder  are  required,  so  that,  if  the 
quarries  be  not  in  work  at  the  time  of  a  visit,  nothing  precise  can 
be  done  as  to  determination  of  horizons. 
No.  2  of  Munier-Chalmas,  and  again  his  No.  3,  agree  exactly 
with  what  obtains  in  the  bottom  and  top  of  the  Sandford  Lane 
‘  Fossil  Bed  ’  respectively. 
The  change  of  genera  which  he  notes  for  No.  2  also  conforms 
with  our  bed,  compared  with  its  predecessors;  while  his  Poecilomorphi 
are  no  doubt  what  I  have  referred  to  in  this  paper  as  “  species 
allied  to  Zurcheri ,”  and  his  Coeloceras  =  i  S 'teplianoceras,’  pars. 
That  this  bed  is  overlain  by  strata  with  Sonninia  propinquans , 
S.  patella ,  and  Stephanoceras  Sauzei  shows  how  necessary  it  was  to 
be  precise  in  noting  the  difference  in  the  fauna  of  the  top  and 
bottom  of  the  Sandford  Lane  ‘  Fossil  Bed.’  It  can  thus  be  shown 
that  there  is  the  same  faunal  succession  in  Dorsetshire,  in  Nor¬ 
mandy,  and  in  Wiirttemberg. 
No.  4  of  Munier-Chalmas  is  apparently  more  restricted  than 
the  zone  of  4  Sonninia  Romani’  of  Haug.1  I  think  it  possible 
that  this  is  an  horizon  which  has  escaped  notice  in  our  own  country. 
There  are,  in  my  cabinet,  Ammonites  from  the  collections  of  Mr. 
Darell  Stephens,  F.G.S.,  and  Mr.  T.  C.  Maggs,  F.G.S.,  with  a  matrix 
unknown  to  me,  although  they  came  from  Sherborne.  Their 
biological  characters  suggest  that  they  may  have  lived  in  a  hemera 
between  that  of  Sauzei  and  Humphriesianum. 
The  fauna  of  the  Humphries iani  hemera  is  given  h}'  Munier- 
Chalmas  as  occurring  in  strata  superior  to  the  beds  of  Witchellia 
Romani — his  No.  5  [A],  op.  cit.  p.  164.  Haug’s  4  zone  of  Sonninia 
Romani ’  evidently  combined  this  horizon  and  the  preceding  one. 
Under  No.  5  B  Munier-Chalmas  gives  a  list  of  Ammonites  which 
agrees  with  that  I  have  noted  from  the  strata  of  the  niortensis  and 
Garantiance  hemerge.  I  should  remark,  however,  that  I  venture  to 
translate  his  4  Oppelia  Truellii  ’  as  not  the  type-form  of  d’Orbigny. 
4  Coeloceras  Daubenyi  (Gemm.)  ’  occurs  in  this  country  at  Burton  Brad- 
stock  ;  but  from  the  evidence  before  me — its  matrix — I  should  assign 
it  a  date  later  than  the  Garantianoe  hemera.  Considering,  however, 
that  one  by  one  discrepancies  of  this  kind  disappear  with  more 
precise  work,  no  stress  need  be  laid  on  it.  The  same  may  be  said 
concerning  other  discrepancies — they  will  certainly  be  explained  as 
the  Ammonite-faunae  become  better  known. 
There  can  be  no  doubt  that  No.  -6  of  Munier-Chalmas  equals 
the  Truellii  hemera  ;  but  in  No.  7  there  is  shown  apparently  a 
division  not  yet  attempted  in  this  country.  In  No.  8,  44  calcaires  a 
Perisphinctes  zigzag  there  is  no  difficulty  in  recognizing  the  fauna 
of  the  zigzag  hemera. 
1  ‘  Les  Chaines  subalpines  entre  Gap  et  Digue,’  Bull.  Serv.  Carte  geol.  France, 
tome  iii.  No.  21,  1891-92,  p.  69.  The  information  concerning  Ammonite- 
horizons  in  this  work  is  very  interesting,  especially  in  comparison  with  those 
of  Dorsetshire.  I  regret  that  I  cannot  refer  to  it  more  fully  now. 
