187 
AMMONITES Braikenridgii. 
TAB. CLXXXIV. 
Spec. Char. Depressed ; radiated ; volutions ex- 
posed ; front rounded ; crossed by the radii ; 
radii furcate ; mouth round ; lip expanded 
into two oblong - lobes. 
R a dii prominent, numerous, rather sharp, and equal to 
the spaces between them : there is a small tubercle upon 
each at the base of the branches ; the thickness of the last 
whorl is rather less than one-third the diameter of the 
shell : there are about three or four volutions. The lip 
is very striking, it commences with a square base, and 
having been continued a little way from the last radius 
it suddenly expands on the sides into two oblong lobes, 
on which are distinctly marked the lines of growth : the 
edges are sharp, and gradually bent a little inwards. 
Perfect terminations of the Ammonites are rare ; I have 
however, met with several specimens indicating the form 
of the lip, but none of them exhibit any thing much out 
of the usual way, excepting some French ones, and those 
now before us : in one of the French specimens the aper- 
ture is much contracted by the lip ; in another, the lip 
forms a single arched lobe slightly bent inwards.* 
These remarkable fossils are from Dundry near Bristol : 
they are composed of foliated carbonate of lime, and are 
imbedded in a compact limestone, replete with rounded 
shining grains of yellowish brown oxide of iron, and the 
remains of various other shells. They enrich the collec- 
tion of George Weare Braikenridge, Esq. of Bristol. 
* Of these I have made an engraving for comparison ; they are found 
in a similar stone with the British one, at Bayeux in Normandy, and were 
presented to me by Mons. de Gerville, to whom I am much indebted for 
the fossil produce of the Cotentin. 
