196 BONES OF THE FACE. 



bone forwards, to the centre of the coronal suture. The 

 two extremities of this suture occupy the place of the 

 anterior and posterior fontanelles. 



The lambdoidal connects the posterior edges of the parietal 

 with the superior margin of the occipital hone, and extends 

 from the posterior end of the sagittal suture, on either side, 

 to the mastoid process of the temporal bone. An extension 

 of this suture, under the name of the additamentum sutures, 

 lambdoidalis, reaches as far down as the foramen lacerum 

 posterius, passing between the mastoid and petrous portions 

 of the temporal and the occipital bones. In this suture we 

 find the ossa triquetra or wormiana. 



The sphenoid suture is as extensive as the very irregular 

 edge of the sphenoid bone, connecting with it the ethmoid, 

 frontal, parietal, temporal, and occipital bones of the cra- 

 nium. 



The ethmoid suture in the same way surrounds the 

 ethmoid bone, uniting it with the frontal and other bones. 



The diameters of the cranium are thus given by Bichat: 

 The antero-posterior is about five inches, and extends from 

 the foramen coecum in front, to the internal occipital pro- 

 tuberance behind. The transverse diameter is four inches 

 and a half, and extends between the bases of the petrous 

 portions of the temporal bones. The vertical diameter is 

 somewhat less than the transverse, and reaches from the 

 middle of the sagittal suture to the anterior edge of the 

 foramen magnum. 



SECTION II. 

 BONES OF THE FACE. 



The Superior Maxillary Bones (ossa maxillaria superi- 

 ora.) The superior maxillary is the principal and largest 

 bone of the face. It enters into the formation of the orbit, 

 the nose, the mouth, and the palate. It is situated so as to 

 form the greater part of the front of the face. Its shape 

 is somewhat triangular, though very irregular. *The two 

 taken together are symmetrical, each lateral portion com- 



