RHYNCHOLITES. 319 
As these belonged to species of hairy brachy- 
urous Crustacea, thatlive exclusively at the bottom 
of the sea, they shew that this Nautilus, though 
occasionally foraging at the surface, obtains part 
of its food from the bottom. As it also had a 
gizzard, much resembling that of a fowl, we see 
in this organ, further evidence that the existing 
Nautilus has the power of digesting hard shells.* 
A similar apparatus is shewn to have existed 
in the beaks of the inhabitants of many species 
of fossil Nautili, and Ammonites, by the abun- 
dance of fossil bodies called Rhyncholites, or 
beak-stones, in many strata that contain these 
fossil shells, e. g. in the Oolite of Stonesfield, in 
the Lias at Lyme Regis and Bath, and in the 
Muschel-kalk at Luneville. 
As we are warranted in drawing conclusions 
from the structure of the teeth in quadrupeds, 
and of the beak in birds, as to the nature of the 
* In PI. 31, Fig. 3 represents the lower mandible, armed in 
front like Fig. 2. with a hard and calcareous margin; and Fig. 4 
represents the anterior calcareous part of the palate of the upper 
Mandible Fig. 2. formed of the same hard calcareous substance 
as its point ; this substance is of the nature of shell. 
These calcareous extremities of both mandibles are of sufficient 
strength to break through the coverings of Crustacea and shells, 
and as they are placed at the extremity of a beak composed of 
thin and tough horn, the power of this organ is thereby materially 
increased. 
In examining the contents of the stomach of the Sepia vul- 
garis, and Loligo, I have found them to contain numerous shells 
of small Conchifera. 
