84 



NAUTILUS biangulatus. 



TAB. CCCCLVIIL— /o^. 2. 



Spec. Char. Discoid, subglobose, with a 

 large umbilicus, and a keel upon each side. 



X HE inner whorls of this Nautilus are half exposed, for 

 each following whorl covers the preceding one as far as 

 the keel upon its side, the front is rounded ; the aperture 

 is transversely elliptical, with the extremities angular in 

 young, but obtuse, in old shells ; its width equals two 

 thirds of the diameter of the last whorl. 



Occurs in the Mountain Limestone near Bristol ; the 

 specimens are in the Collection of the Rev. Dr. Beeke, 

 Dean of Bristol. 



