CS) 
DIVISION I. NUMMULACER, 
GENERA. 
4, {Nummuta. Lam. Ca- 
MERINA. Brug. 
Exterior form lenticu- No siphon. Marine. 
Jar, without any apparent 
opening ; a spiral cavity 
divided by septa mto an 
infinity of small chambers 
(1). 
a. Perfectly discous. Only one row of cham- Fossil and living. 
Pl. 1, fig 3,4. (2) bers to each turn of the 
spire. 
b. (Siderolites, Lam.) The edge with bluntor Microscopic. 
sharp rays. P}. 4, fig. 23. 
ec. (Renulites, Lam.) Several rows of cham- ......... a 'aKb so chins acai 
bers to each turn of the 
spire, 
2. DiscorsirEs. (3) Lam. 
Spiral, all the turns vi- No siphon. 
sible and exposed. (4) PI. 
1, fig. 5. 
(1) The Nummutites are amongst the most widely-spread fossils, forming, al- 
most exclusively, entire chains of calcareous hills and immense beds of building 
stone. The Pierre de Laon is composed of Nummulites; the pyramids of Egypt 
were constructed with stone of this nature, and are raised upon the rocks which 
supplied it. They were formerly considered, by some, to be Lusus Natura, by 
which portions of calcareous matter assumed the form of organised hoties? by 
others, as petrified seeds, opercula, bivalve shells, etc. etc. Breynius, in 1732 bana 
Gesner, in 1758, concluded them to be univalve shells, very analogous to the Am- 
monifes. Bruguiere thought that the animal was contained in the last chamber of 
the shell. Cuvier considers them to be interior shells. To observe the chambers 
more distinctly, let a drop of ink fall on the worn face, and when it is quite dry, 
rub the Nummulite delicately on a stone to take off the exterior black, after which 
all the points which have retained the ink become evident on a white ground, and 
the interior organization is perfectly discovered. This practice is useful for recog- 
nising several other delicate fossil shells. 
(2) These are the most common and the largest amongst the fossil species, but 
the living species are very small. ; 
(3) The termination tes distinguishes the Genera exclusively fossil, no analogous 
living species having been yet discovered, 
(4) This character distinguishes them from the Spirolinites, the absence of the 
siphon from the Naut#. 
