190 
ribbed edges of the whorls: the radii are nearly close 
together, and very regular until just before the last whork 
is completed, when their place is supplied by two or 
three irregular waves ; the shell is then finished with a 
sharp edge. 
This species occurs in a marly Limestone, which is 
replete with grains of Iron Ochre : the place of the shell 
is supplied by foliated carbonate of Lime. It is from 
Bayeux, in Norraandy. 
AMMONITES Erongniartt. 
"LAB, Anwsoltg..2- 
Spec. Cuar. Gibbose; radiated ; umbilicate ; in- 
ner whorls concealed; umbilicus minute ; 
aperture transverse, oblong, arched, with a 
thick or inflected lip ; radii fureate, bent. 
"TP uicxness about two-thirds the diameter: the radii are 
close, waved, and very regular: the umbilicus is minute, 
round within, but oblong externally, in consequence of 
the last whorl being carried forward in a straight line for 
a short distance, after which it turns suddenly towards 
the mouth. 
This is found in the same state of preservation in the 
same stratum with fig. 3; and it may be worthy of obser- 
vation, that the Rev. Mr. Buckland possesses in his 
cabinet, a specimen from Yeovil of the same species with 
this, but in a stone very sparingly furnished with the fer- 
ruginous grains, and such as there are being in a decom- 
posed state. 
I have named these. two last shells, the one as a testi- 
mony of respect to an enlightened and warm friend of 
science in general, and of Natural History in particular, 
Mons. de Gerville, who bas laboured with much assiduity 
in collecting and arranging the fossils of the Cotentin :--- 
the other in honor of Brongniart; its rotundity may be 
considered as a type of the orb of knowledge spread 
abroad by that luminary, in conjunction with Cuvitr, 
after whom I have already named the spreadimg Inoce- 
ramus, Cuvieri. 
My kind friend M. de Gerville, above named, furnished 
me with all the three species figured on this plate. 
