OSTEOLOGY AND SYNDESMOLOGY. 17 
This plate is perforated by numerous holes, through which pass the ramifi- 
cations of the olfactory nerve. The lateral portions of the ethmoid (pl. 121, 
fig. 10°) are covered by the frontal bone. That portion of the ethmoid 
which enters into the orbitar cavity ( fig. 14°) is called the os planum, or 
lamina papyracea. The internal or nasal face forms part of the nostril. 
Between the two halves of the bone, and beneath the cribriform plate, is 
the nasal lamella, or lamina perpendicularis (fig. 11°, 127, 18°), which, in 
conjunction with the vomer, divides the nasal cavity into halves. In the 
posterior middle portion of the nasal face is a deep furrow, called the supe- 
rior nasal meatus (fig. 15°). The upper margin of this meatus is constituted 
by the upper turbinated bone, the middle turbinated bone being below. 
B. Bones of the Face. 
The face is composed of fourteen bones, of which thirteen enter into the 
composition of the upper jaw. Of these, twelve are in pairs: the ossa max- 
illaria superiora, ossa malarum, ossa nasi, ossa ungues, ossa turbinata inferi- 
ora, ossa palati. The single vomer constitutes the thirteenth, and the os 
maxillare inferius, or lower jaw, the fourteenth. 
Superior maxillary bones, ossa maxillaria superiora (pl. 121, figs. 1°, 4°; 
pl. 123, fig. 6). These are the largest of the bones of the face, and occupy 
the anterior part of the upper jaw. ach consists of a central portion, 
with various processes for articulation with the contiguous bones. This 
central portion is hollowed out into a large cavity, called the antrum high- 
morianum, or maxillary sinus, communicating with the cavity of the nose. 
‘The superior face is formed by a thin plate, the orbitar process, constituting 
the floor of the orbit (pl. 123, fig. 6°). Inthe posterior part of this plate is 
a groove, which leads to a canal terminating at the front of the bone in the 
infra-orbitar foramen (fig. 6*; pl. 121, fig. 4°), through which pass the 
infra-orbitar nerve and an artery; below this, again, is a depression in the 
front of the bone (pl. 123, fig. 6°), known as the fossa mazxillaris, filled up 
during life by muscle and fat. The nasal process (jig. 6”*) connects the 
bone with the frontal and nasal bones, and exhibits an emargination inferiorly 
and anteriorly (fig. 6°), to which is attached the cartilage of the nose. The 
malar or zygomatic process (jig. 6") connects it with the malar bone. The 
alveolar processes, for lodging the eight teeth of the adult, are situated in the 
external inferior portion, and the palatine process (pl. 121, fig. 6”) consti- 
tutes the greater portion of the bony palate. In the suture of the two max- 
illary bones, and immediately behind the front alveolar processes, we find 
the foramen incisivum (fig. 6), which bifurcates above, sending a branch 
into each nostril. Through this passes a branch of the spheno-palatine 
nerve. The intermaxillary bone, so universal in the lower Mammalia, is 
wanting as a distinct element in the adult man (it being fused with the true 
maxillary), but in the young foetus may be distinctly recognised ; it rarely 
exists after birth. The articulations of the maxillary bones are with the 
frontal, nasal, unguiform, malar, and ethmoid, above; with the palatine, 
behind ; with the vomer, in the middle; and with the inferior spongy bone, 
by the nasal surface. 
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