The _Parietal Bones_ (_d_) make a large Cavity, in which the greatest Part of the Brain is contained, and _this_ we may call the _Sinciput_. Behind this Bone are placed the _Ossa Temporum_ (_f f_) in which lye the Organs of _Hearring_; and behind Them a Bone (_g_) which, we may call the _Os Occipitis_, covers the posterior Part of the Brain. This is joined to the first _Vertebra_ of the Neck (_h_), by a Spherical Articulation, as all the _Vertebræ_ are to one another; and this is the Reason why this Creature can turn its Head and Body so much, and so nimbly, every way. To some of _These_ there are Two other Bones Articulated for particular Uses. The First of _Them_, which serves as a _Basis_ to the Articulation of the Rest (_a_, _Fig. 4._), is fastned by one Extremity to a small Proturberance (_i_, _Fig. 2._) in the middle and lateral Part of the _Os Sincipitis_, and running back towards the _Vertebræ_, lyes in the same Plain with the _Sinciput_. This Bone has a Motion, tho’ very inconsiderable, both upwards and downwards. By means of This, the opening of the Mouth is somewhat inlarged in the Time of _Deglutition_. That End of this Bone, which is next to the _Vertebræ_, is articulated at oblique Angles with _Another_ (_b_) placed Horizontally, and whose Motion is forwards and backwards, being made chiefly for moving the Bones of the upper and lower Jaw, into which the Teeth are inserted. By reason of this kind of Articulation, It cannot contribute any thing towards widening the Mouth for Swallowing. This Bone, and That with which it is joined, I call the _Common Bones_. The _Upper Jaw_ (_Fig. 3._) is, besides the Teeth, composed on each side of _three_ Bones. The _First_ (_a_), into which the Poisonous _Fangs_ are fixt, is articulated with the Anterior Protuberance of the _Orbit_ of the Eye; and has a Motion of Flexion and Extension, that is, forwards and backwards, by which the _Fangs_ are Erected or Depress’d. It is small at the Joint, but grows broader by degrees, to a pretty large _Basis_, the better to contain a considerable Number of _Teeth_. It is _Spongy_ like the Substance of the _Vertebræ_, and no ways fit to be the immediate Organ of _Hearing_, as Mr. _Charas_ and some others have imagined. The _Second_ (_c_), is a broad thin Bone, Articulated by _one_ Extreme to the _Former_, (_f_), and by the _other_ firmly fixt to the middle of the _third_ Bone. When _this_ is thrust forwards, it likewise pushes the _First_, and by this means the _Erection_ of the _Fangs_ is helped; and when it is pull’d backwards, they are _depressed_. The _third_ Bone (_e d_), is join’d by one Extremity (_e_), to the End of one of the Bones of the Lower Jaw (_c_, _Fig. 4._), And being somewhat crooked, turns in a little towards the _Basis_ of the _Cranium_, and running along the Inferior Part of it towards the _Nose_, terminates near the Internal and Anterior Part of the _first_ Bone.