224 
NAUTILOIDEA. 
Sp. Char. “ A smooth, or slightly furrowed, and somewhat in- 
flated shell, with rounded and embracing volutions in the young 
state, which become truncate, or subquadrate, in the adult, and 
having a very shallow, or slightly impressed, umbilicus. Aperture 
about twice as wide as it is high, flattened above, and somewhat 
compressed laterally. 
“This shell has the general form of the X. latidor.mtas^ d'Orb. 
l^ — Toarcensifi, d’Orb.], but the broad umbilicus and more quadrate 
form of the young shell in that species readily distinguish them. 
This species belongs to the section of the imperforate Nautili, of 
which N. truncafus^ Sow., N. clausus, d Orb., are examples ; a 
group, the species of which were not apparentl}' numerous during 
the Jurassic period.’’ {Morris and Lijcett.) 
Eemarlcs. This species finds it^ nearest ally in Nautilns clausus. 
d’Orbigny, but the latter has much more flexuous septa, as carefull}' 
indicated in d’Orbigny’s plate (Terr. Jurass. pi. xxxiii. fig. 4). 
besides which the periphery is much narrower than is the ca.se in 
Morris and Lycett’s species. 
N. Baheri has already been compared with this species, under tlie 
description of the former. 
A specimen in the Collection from the Great Oolito of Kings- 
thorpe, Northamptonshire (No. 82345), may belong to this species ; 
it is a fragment of the septate part of the shell ; it shows no 
sculpture. 
I have referred a specimen from the Inferior Oolite of Les Moutier, 
Calvados, to the present species on account of the close resemblance 
to the latter in the form of its shell, though the test is almost 
smooth, with, however, indications of ribbing on the sides of the 
shell. It may be a variety of ^[orris and Lycett’s species. 
None of the specimens from Minchinhampton have the septa 
preserved, the inside of one which was broken open being partly 
hollow and lined with crystals of calc-spar. 
The specimen from Kingsthorpe exhibits rather approximate, 
slightly flexuous septa. 
Horizon. Inferior Oolite. Great Oolite. 
Localities. Minchinhampton, Gloucestershire (Inferior Oolite) ; 
Kingsthorpe, Northamptonshire (Great Oolite). 
Well represented in the Collection. 
