OSSA MALARUM. 91 



above to the frontal bone ; behind to the os planum ; before 



and below to the maxillary bone. It sometimes is extended 



into the nose, as low as the upper edge of the inferior spongy 

 bone. 



Ossa Malarum. 



The ossa malarum are the prominent square bones which 

 form the cheek, on each side. Before, their surface is convex 

 and smooth ; backward, it is unequal and concave, for lodging 

 part of the temporal muscles. 



The four angles of each of these bones have been reckoned 

 as processes. The one at the external canthus of the orbit 

 called the superior orbitar process, is the longest and thickest, 

 The second terminates near the middle of the lower edge of 

 the orbit in a sharp point, and is named the inferior orbitar 

 process. The third, placed near the lower part of the cheek, 

 and thence called maxillary, is the shortest and nearest to a 

 right angle. The fourth, which is called zygomatic, because it 

 is extended backwards to the zygoma of the temporal bone, 

 ends in a point, and, has one side straight and the other sloping. 

 Between the two orbitar angles there is a concave arch, which 

 makes about a third of the external circumference of the orbit, 

 from which a fifth process is extended backwards within the 

 orbit, to form near one-sixth of that cavity ; and hence it may 

 be called the internal orbitar process. From the lower edge 

 of each of the ossa malarum, which is between the maxillary 

 and zygomatic processes, the masseter muscle takes its origin. 



On the external surface of each cheek bone, one or more 

 small holes are commonly found for the transmission of small 

 nerves or blood-vessels from, and sometimes, into the orbit. 

 On the internal surface are the holes for the passage of the 

 nutritious vessels of these bones. A notch, on the outside of 

 the internal orbitar process of each of these bones, assists to 

 form the great slit common to this bone, and to the sphenoid, 

 maxillary, and palate bones. 



The substance of these bones is, in proportion to their bulk, 

 thick, hard, and solid, with some cancelli. 



