4.  Chalk  Marl.
5.  Chloritic  series  (or  Upper  Greensand).
6.  Gault.
LOWER   CRETACEOUS    OR  NEOCOMIAN.
Marine

1.  Upper  Neocomian,  see  p.  284.
2.  Middle  Neocomian,  see  p.  288.
3.  Lower  Neocomian,  see  p.  289.
Freshwater

Wealden  Beds

(upper  part).
MaScht* Faxo'eTnd'
White'chalk.'


Maestricht  Beds.— On  the  banks  of  the  Meuse,  at  Maestricht,
reposing  on  ordinary  white  chalk  with  flints,  we  find  an  upper
Fig.  226.  calcareous  formation  about  100  feet  thick,

the  fossils  of  which  are,  on  the  whole,
very  peculiar,  and  all  distinct  from  ter-
tiary species.     Some  few  are  of  species
common   to   the    inferior    white    chalk,
among  which  may  be  mentioned  Belem-
nitella  mucronata  (fig.  226)   and  Pecten
quadricostatus,  a  shell  regarded  by  many
as    a    mere    variety    of   P.    quinquecos-
tatus  (see  fig.  270,  p.  275).     Besides  the
Belemnite  there  are  other  genera,  such
as  Baculites  and  Hamites  never  found  in
strata  newer  than  the  cretaceous,  but
frequently  met  with  in  these  Maestricht
outer  surface,  and  cha-  beds.       On    the    other    hand,     Voluta,
b.  IsSti™tof  tame,  showing  Fasciolaria,  and  other  genera  of  univalve
place  of  phragmocone.*       shells,  usually  met  with  only  in  tertiary
strata,  occur.
The  upper  part  of  the  rock,  about  20  feet  thick,  as  seen  in  St.
Peter's  Mount,  in  the  suburbs  of  Maestricht,  abounds  in  corals
and  Bryozoa,  often  detachable  from  the  matrix  ;  and  these  beds
are  succeeded  by  a  soft  yellowish  limestone  50  feet  thick,  exten-
sively quarried  from  time  immemorial  for  building.  The  stone
below  is  whiter,  and  contains  occasional  nodules  of  grey  chert
or  chalcedony.
