18 DESCRIPTION OF THE SKELETON. 



orbitar Orbitar Fossa (Plates last referred to). — The bony orbit is deficient 



Fossa. 



at its posterior part. Near the junction of the jugal and maxillary bones 

 is an eminence, which forms the infero-posterior part of the bony orbit. In 

 front of this is a curve of the jugal bone, which, being continued by a curve 

 in the maxillary bone, terminates at the inferior anterior orbitar process 

 of the os frontis. A curved line extending first upwards, then backwards, 

 forms the superior edge. The inferior anterior orbitar process above men- 

 tioned forms a projection an inch and a half high, dividing the anterior 

 part of the orbit into two portions, as just stated. The bony circle 

 terminates posteriorly in the superior orbitar process. 



The bony orbit, then, is constituted in the following manner : — At its 

 postero-superior part is the large, thick projection of the superior orbitar 

 process ; the bone then arches forwards to a second remarkable projection, 

 the inferior anterior orbitar process ; thence, extending downwards and 

 backwards, it terminates inferiorly and posteriorly in the jugal process of 

 the orbit. The ridge thus described composes about two-thirds of a circle, 

 flattened in its antero-posterior direction. 



LOWER JAW. 



The outline of the lower jaw (Plates II. III. Y.) has the form of a V, 

 the anterior extremity being almost pointed. We shall describe first the 

 branches, and then the body of the bone, on their outer and inner faces, 

 comprehending the description of the superior and inferior edges with that 

 of the faces respectively. 

 External The external face is divided into two parts ; the posterior of which, or 



Face. 



articulating portion, has a quadrangular form. At the upper edge of the 

 quadrangle, we see the narrow condyloid process, measuring six inches in 



