11 7 
AMMONITES subkevis, 
TAB. LIV. 
Spec. Char. Orbicular (rather depressed when 
young), inner whorls exposed within the um- 
bilicus which is deep, undulated, and has an 
angular edge. Septa numerous, with five 
principal undulations which are repeatedly 
divided into many lesser rounded ones. 
Orbulites laevis? Lamarcke , Anim. sans vertebr . 54. 
Nautili tes, &c, Luidii Lithopli. Br it. Tab. 6 , F. 292. 
When full grown about five inches in diameter with a 
very deep conical umbilicus about one inch and a quarter 
wide. The shell is smooth on the surface and free from 
undulations, except within the umbilicus and on the young 
§helh The margins of the septa traced upon the stone 
resemble some pinnate leaves, such as those of curled 
parsley. Aperture very wide, semicircular, truncated at 
the sides. Siphunculus close to the outer margin. 
From Christian Malford, it is undoubtedly the same as 
the Kellaways rock Lyas shell, and is a fine example of 
difference in proportion arising from age, getting rounder 
as it has grown larger. The inner or younger part of this 
specimen at about a quarter of an inch long is only half as 
wide as long, and has very conspicuous rising transverse 
ribs, although so small: these become less sharp or more 
rounded as the shell advances in growth, being alternately 
long and short, and some furcate, at about two and an half 
inches or three inches long these striae begin to be indistinct, 
