THE SKIN AND SKELETON. 
143 
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. 
yvjuuK. HYOID ARCH. 
PREMAXILLA. MAXILLA. PALATINE. PTERYGOID. 
LOWER JAW, OR MANDIBLE. 
THE SKULL OF THE DOG. 
Fig. 108.— Under surface. Fig. 109.— Upper surface. Fig. 110.— Longitudinal ver¬ 
tical section; one-half natural size: SO, supraoccipital; ExO, exoccipital; BO, 
basioccipital; IP, interparietal ; Pa, parietal; Fr, frontal; Sq, squamosal; Ma, 
malar; L, lachrymal; Mx, maxilla ; PMx, premaxilla; Na, nasal; MT, maxillo- 
turbinal; ET, ethmoturbinal; ME, ossitied portion of the mesethmoid; CE, cri¬ 
briform, or sieve-like, plate of the ethmoturbinal; VO, vomer; PS, presphenoid; 
OS, orbitosphenoid; AS, alispheuoid; BS, basisplienoid; PI, palatine; Pt, 
pterygoid; Per, periotic ; Ty, tympanic bulla ; an, anterior narial aperture; ap, 
or apf, anterior palatine foramen; ppf, posterior palatine foramen ; io, infra¬ 
orbital foramen; pof, postorbital process of frontal bone ; op, optic foramen ; sf, 
sphenoidal fissure; fr, foramen rotundura, and anterior opening of alispheuoid 
canal; as, posterior opening of alispheuoid canal; fo, foramen ovale ; Jim, fora¬ 
men lacertim medium; of, glenoid fossa; gp, postglenoid process; pgf, post¬ 
glenoid foramen ; earn, external auditory meatus; sm, stylomastoid foramen; 
ftp, foramen lacerum posterius; cf, condylar foramen; pp, paroccipital process; 
oc, occipital condyle; fm, foramen magnum ; a, angular process ; s, symphysis of 
the mandible where it unites with the left ramus ; id, inferior dental canal; cd, 
condyle ; cp, 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, hyoideau ap¬ 
paratus, or os linguae, 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 and other Apes. 
* 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 four occipitals coalesce into onu. 
