CRANIUM 



155 



with the squamous, there is a foramen which communicates with the parieto- 

 temporal canal. The condyles are somewhat flattened and are widely separated 

 above; at the inner side of each 

 is a short condyloid canal, which 

 opens into the parieto-temporal 

 canal. The paramastoid processes 

 are very short. The basilar part 

 is wide and joins the bulla ossea on 

 either side; its lower surface is 

 flattened and the tubercles are at 

 the junction with the bulla. The 

 hypoglossal foramen is small and 

 is close to the foramen lacerum 

 posterius; the latter is bounded in 

 front by the liulla ossea, behind and 

 internally by the occipital bone. 



The interparietal bone fuses 

 with the occipital before birth. 

 It forms the high posterior part of 

 the sagittal crest, and is wedged in 

 between the two parietal bones. 

 The tentorium osseum is thin and 

 curved, concave ventrally. Its base 

 concurs with the occipital and parie- 

 tal bones in the formation of a trans- 

 verse canal which is continuous with 

 the parieto-temporal canals. 



The parietal bone is rhoml^oid 

 in outline and is strongly curved. It 

 is extensive and forms the greater 

 part of the roof of the cranial cavity. 

 At the junction of the right and left 

 bones there is a prominent sagittal 

 crest which is continued upon the 

 frontal bones. The lower border 

 articulates with the temporal wing 

 of the sphenoid by its anterior part 

 and with the squamous temporal in 

 the remainder of its extent. The 

 external surface enters into the for- 

 mation of the temporal fossa. The 

 internal surface is marked by digital 

 impressions, and by grooves for the 

 middle meningeal artery and its 

 branches. 



The external surface of the 

 frontal bone is crossed by a 

 frontal crest, which extends in a 

 curve from the sagittal crest to the 

 supraorl)ital process, and separates 

 the frontal and temporal parts. 



The frontal parts of the two bones form a central depression and slope downward 

 and forward. The supraorbital process is very short, so that the orl)ital margin 

 is incomplete as in the pig. The supraorbital foramen is absent. In front there 



Fig. 123. — Skui.l of Dog, Dorsal View. 

 /, Occipital; //, parietal; ///, frontal; IV, lacrimal; 

 V, malar; 1'/, squamous temporal; VII, nasal; VIII, max- 

 illa; IX, premaxilla; 1, supraoccipital; 2, interparietal; S, 

 parieto-occipital suture; 4, occipital crest; 6, sagittal crest; 

 6, parieto-frontal suture; 7, squamous suture; S, parietal emi- 

 nence; 9, antero-external angle of parietal bone; 10, frontal 

 crest; 11, 14, orbital margin; 12, supraorbital process; 13, 

 frontal fossa; lo, temporal part of frontal bone; 16, nasal 

 process of frontal bone; 17, frontal suture; IS, lacrimal fora- 

 men; 19, maxillary process of frontal bone; 20, lacrimo-maxil- 

 lary suture; 21, frontal process of malar bone; 22, lacrimal 

 process of malar; 23, zygomatic process of malar; 24, zygo- 

 matic process of squamous temporal; 24', posterior end of 

 nasal bone; 25, nasal suture; 26, anterior end of nasal bone; 

 27, infraorbital foramen; 23, canine tooth; 29, cheek tooth; 

 30, frontal process of maxilla; 31, body, 32, nasal process, 

 33, palatine process of premaxilla; 34, palatine fissure; 35, 

 incisor teeth. (EUenberger-Baum, Anat. d. Hundes.) 



