of) 



BOXES OF THE HEAD. 



with the nasal spine of the frontal bone, and frequently with the perpen- 

 dicular plate of the ethmoid. The anterior surface, concave at its upper 

 part, convex in the rest of its extent, presents a minute vascular foramen ; 

 the posterior or nasal surface is marked by a groove for the passage of the 

 nasal nerve. 



THE LACHRYMAL BONE. 



The lachrymal bone, or os unguis, is a thin scale of bone placed at the 

 anterior and inner part of the orbit. It articulates superiorly with the 

 frontal bone, posteriorly with the orbital plate of the ethmoid ; anteriorly 

 it presents a longitudinal or vertical groove, and articulates with the 

 ascending process of the superior maxillary bone, completing with it the 

 groove for the lachrymal sac ; inferiorly it articulates in its greatest extent 

 with the orbital plate of the superior maxillary bone, while its anterior 



Fig. 44. Fig. 44. RIGHT LACHRYMAL BONE, FROM THE OUTSIDE. | 



1, upper or frontal border ; 2, the orbital surface ; 3, lachrymal 

 groove ; 4, the hooked process which meets the inferior turbinated bone. 



grooved part projects downwards, taking part in the formation 

 of the lachrymal canal, and terminates in a pointed extremity, 

 hamulus lachrymalis, which fits into an angle between the 

 superior maxillary and inferior turbinated bone. The inner 



surface looks superiorly to the anterior ethmoidal cells, and inferiorly to the 



middle meatus of the nose. 



THE INFERIOR TURBINATED BONE. 



The inferior turbinated, or spongy bone, is a slender lamina, attached by 

 one margin from before backwards along the lateral wall of the nose, and 



Fig. 45. 



B 



Fig. 45. THE INFERIOR TURBINATED BONE OF 

 THE RIGHT SIDE. f 



A, from the outside ; B, from the inside. 



1, anterior angle ; 2, posterior angle ; 1, 3, 2, 

 inferior free border ; 4, internal convex surface ; 

 5, part of the bone articulating with the uncinate 

 process of the ethmoid ; 6, portion articulating 

 with the lachrymal ; 7, the outer concave sur- 

 face ; 8, the maxillary process or deflected scale 

 of bone from the upper border, which, by union 

 with the superior maxillary, forms a part of the 

 inner wall of the maxillary sinus. 



projecting into the nasal cavity, so as to 

 divide the middle from the inferior meatus. 

 It is slightly convoluted, its convexity look- 

 ing upwards and inwards, and its free mar- 

 gin being dependent, slightly thickened, 



and rolled upon itself. The attached margin articulates anteriorly with the 

 oblique ridge below the ascending process of the superior maxillary bone, 

 and ascends abruptly to form the lachrymal process and complete the 

 lachrymal canal and articulate with the lachrymal bone ; behind this it bends 

 downwards in the maxillary process, forming part of the inner wall of the 

 antrum below the entrance into that cavity ; above and behind this, it 

 presents a small projection which articulates with the uncinate process of 

 the ethmoid, and posteriorly it is attached to the horizontal line on the ver- 

 tical plate of the palate bone. 



