135 
they are mere lines ; thus leading to those Ammonites 
which have deep furrows in several parts of their whorls, 
and which have been elevated into another genus. The 
radii form rings that are split just before they pass over 
the front. Upon the inner laminae of the shell these 
rings are interrupted where they pass over the siphuncle, 
but on the outer surface they are continuous. 
The specimen represented at fig. 1. is a portion of an 
indurated Marl Nodule found amongst Alluvium in the 
parish of Braunston in N orthamptonshire, by Miss Baker, 
whose zeal in collecting the natural productions of the 
district, to assist her brother in a general history, has in- 
duced me to commemorate her name. 
Fig. 2. represents a cast in Pyrites. 
AMMONITES laevigatus. 
TAB. DL XX.— Jig. 3. 
Spec. Char. Depressed, smooth ; inner whorls ex- 
posed ; aperture transversely oblong ; the edge 
of the aperture thickened, produced in the 
front. 
The convex smooth whorls of this shell are so like the 
innermost ones of some large Ammonites, that I suspect 
it to be very young, probably the first period of its 
growth only has been completed. It therefore serves to 
introduce us to the two following species, as well as to 
Ellipsolites funatus (tab. 32.), andMontfort’s genus Pla- 
nulites. 
Drawn from a specimen in the collection of H. T. De 
laBeche, Esq., who found it in the Lyas near Lyme-Regis. 
