12 
septae are 1 nearly the same as in the last, as I find from 
separated specimens which I possess. It appears to be a 
new species, and I have called it centralis because the 
siphunculus is central. 
The specimen is from a well dug in Richmond Park, 
175 feet deep in the great Clay formation. It is filled up 
with a dullish Pyrites, and the Shell is slightly pearly. 
NAUTILUS ziczac . — Lowest figure . 
Spec. Char. Involute, inner turns concealed,, aper* 
ture bluntly triangular, septae concave much 
recurved at their ends with a deep indenture in 
the edge on each side, siphunculus nearest to 
the inside. 
It is about one third of its diameter in thickness, being a 
flattish Shell. The remarkable zigzag appearance of the 
septae and their broad edges distinguish this Shell pretty 
readily from any I before knew, except a large one figured 
by Mr. Parkinson in his Organic Remains, vol. 3, tab. 7, 
fig. 15, and which may perhaps prove to be an older 
specimen of the same Shell, but the great indentation in the 
edge of each septae is contracted towards the middle so as 
to become suddenly acute, and not turning regularly round 
as in this, but it must be remembered that the specimen he 
has figured is a cast, and not the Shell. My specimen is 
from High gate , and is the only one I have met with. 
