MAESTRICHT BEDS. 
283 
Fi^. 226 . 
UPPER CRETACEOUS OR CHALK PERIOD. 
1. Maestridit Beds and Faxoe Limestone. , • 
2. Upper White Chalk, with flints. 
3. Lower White Chalk, without flints. 
4. Chalk Marl. 
5. Chloritic series (or Upper Greensand). 
6. Gault. 
LOWER CRETACEOUS OR NEOCOMIAN. 
Marine. Fresh-water. 
1. Upper Neocomian, see p. 808 ,') 
2. Middle Neocomian, see p. 312. Wealden Beds (upper part). 
3. Lower Neocomian, see p. 312.) 
Maestricht Beds ,—On the hanks of the Meuse, at Maes- 
tricht, reposing on ordinary white chalk with flints, we find 
an upper calcareous formation about 
100 feet thick, the fossils of which are, 
on the whole, very peculiar, and all dis¬ 
tinct from tertiary species. Sojne few 
are of species common to the inferior 
white chalk, among which may be men¬ 
tioned Belemnitella miicronata (Fig. 
226) and Pecten quadricostatus,^ a shell 
regarded by many as a mere variety 
of jP. quinquecostatus (see Fig. 270, 
p. 300). Besides the Belemnite there 
are other genera,^ such as Bacidites and 
Hamites,^ never found in strata newer 
than the cretaceous, but frequently 
met with in these Maestricht beds, 
On the other hand, Vokita,, Fasciola- 
ria^ and other genera of univalve 
shells, usually met with only in ter¬ 
tiary 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, extensively quarried from time immemorial for 
building. The stone below is whiter, and contains occasion¬ 
al nodules of gray chert or chalcedony. 
M. Bosquet, with whom I examined this formation (Au¬ 
gust, 1850), pointed out to me a layer of chalk from two to 
four inches thick, containing green earth and numerous en- 
crinital stems, which forms the line of demarkation between 
the strata containing the fossils peculiar to Maestricht and 
* For particulars of structure, see p. 318. 
1 
p 
ii 
Belemnitella mucronata, 
Maestricht, Faxoe, and 
White Chalk. 
vascular impression on out¬ 
er surface, and characteris¬ 
tic slit. &. Section of same, 
showing place of phragmo- 
cone.* 
