THE SKIN AND SKELETON. 141 
BONES OF THE MAMMALIAN SKULL.* 
BRAIN-CASE. 
NASAL, FRONTAL. PARIETAL. SUPRAOCCIPITAL, 
LAC|HRYMAL. SQUAMOSAL, 
NOSE, ORBITOSPHENOID. EYE, ALISPHENOID. PERI- EAR. OTIC. EXOCCIPITAL. 
MALAR. TYMPANIC, 
ETHMOID. PRESPHENOID. BASISPHENOID, BASIOCCIPITAL. 
VOMER. HYOID ARCH, 
PREMAXILLA. MAXILLA. PALATINE, PTERYGOID. 
LOWER JAW, OR MANDIBLE, 
THE SKULL OF THE DOG. 
Fig. 108.—Under surface. Fria. 109.—Upper surface. Fra. 110.—Longitudinal ver- 
tical section; one-half natural size: SO, supraoccipital; ExO, exoccipital; BO, 
basioccipital; JP, interparietal; Pa, parietal; Fr, frontal; Sq, squamosal; Ma, 
malar; ZL, lachrymal; Mz, maxilla; PMa, premaxilla; Na, nasal; M7, maxillo- 
turbinal: #7, ethmoturbinal; MW2#, ossitied portion of the mesethmoid; CE, cri- 
briform, or sieve-like, plate of the ethmoturbinal; VO, vomer; PS, presphenoid ; 
OS, orbitosphenoid; AS, alisphenoid; BS, basisphenoid; Pl, palatine; Pt, 
pterygoid; Per, periotic; 7, tympanic bulla; an, anterior narial aperture; ap, 
or apf, anterior palatine foramen; ppf, posterior palatine foramen; 70, infra- 
orbital foramen; pof, postorbital process of frontal bone; op, optic foramen; sf, 
sphenoidal fissure; fr, foramen rotundum, and anterior opening of alisphenoid 
canal; as, posterior opening of alisphenoid canal; fo, foramen ovale; jim, fora- 
men lacerum medium; gf, glenoid fossa; gp, postglenoid process; pf, post- 
glenoid foramen; eam, external auditory meatus; sm, stylomastoid foramen; 
Jip, foramen lacerum posterius ; ¢f, condylar foramen; pp, paroccipital process ; 
oc, occipital condyle; fm, foramen magnum; a, angular process; 8, symphysis of 
the mandible where it unites with the left ramus; id, inferior dental canal; ed, 
condyle; ep, coronoid process; the * indicates the part of the cranium to which 
the condyle is articulated when the mandible is in place; the upper border in 
which the teeth are implanted is called alveolar; sh, eh, ch, bh, th, hyoidean ap- 
paratus, or os lingua, supporting the tongue. In the skulls of old animals, 
there are three ridges: occipital, behind; sagittal median, on the upper surface ; 
and superorbital, across the frontal, in the region of the eyebrows. The last is 
highly developed in the Gorilla. 
* In this diagram, modified from Huxley’s, the italicized bones are single; the 
rest are double. ‘Those in the line of the Ethmoid form the Cranio-facial Axis: 
these, with the other sphenoids and occipitals, are developed in cartilage; the rest 
are membrane bones. In the Human skull, the three occipitals coalesce into one. 
