48 



THE SKELETON OF THE HORSE 



Its lower part is perforated centrally by a large, almost circular opening, the 

 foramen magnum (Foramen occipitale magnum), at which the brain and spinal 

 cord join. The foramen is bounded laterally and dorsally by the lateral parts of 

 the bone, and ventrally by the basilar part or process. Above the lateral parts — 

 but not entering into the formation of the foramen magnum — is the squamous part. 



The lateral parts (Partes laterales) bear the occipital condyles (Condyli 

 occipitales), which articulate with the atlas. The condyles are obliquely placed, 

 wide apart dorsally, and separated by a small interval ventrally. The articular 

 surface is curved so sharply in the dorso-ventral direction as to form a blunt ridge 



Occipital crest - 

 Upper border of 



Foramen magnum 



Hypoglossa I foramen ^ 



For. laccrum posterius _ 



Stylo-mastoid foramen ' 



Hyoid process 



Muscular process 



For. laceruyn anterius 

 Tubercles at spheno- 

 occipital junction i^v 



Alar foramen -4-~ 



Pterygoid process 

 of sphenoid 

 Pterygoid bone 



Vomer (aloe) 



Pterygoid process of 



palate bone 



Palate bone {perpen- __ 



dicular part) 



Alveolar tuberosity 



Posterior nares ._J | 



Last molar tooth - 



Median crest for Kg. nuchce 



Occipital condyle 



Paramastoid process 



Co7idyloid fossa 



- Mastoid process 



^---\ Bulla ossea 



Postglcnoid process 



- — Glenoid cavity 



Temporal condyle 

 ^-\- Zygomatic process 

 ~^ Infratemporal fossa 



Zygomatic process of 

 malar 



■'- Pterygo-palatine fossa 

 Maxillary hiatus 

 — J — Maxillary tuberosity 



— Facial crest 



— Hamulus of pterygoid 



- ■ Vomer 



__ Palate bo7\c {horizon- 

 tal pari) 

 V. ,, -,f Ant. palatine foramen 



^4k-| / Palatine groove 



Palatine process of 



maxilla 



Fig. 27. — Line Ur.\wing of Posterior H.\lf of Base of Skull of Horse, Without Mandible. (Key to 



Fig. 28.) 

 1, Incisura carotica; 2, incLsura ovalis; 3, incisura spinosa; 4, external orifice of parieto-temporal canal; 

 5, Eustachian canal; 6, petro-tympanic fissure; 7, external auditory canal; 8, hyoid process; 9, Vidian groove; 

 10, supraorbital process; A, basilar part of occipital; B, body of sphenoid; C, temporal wing of sphenoid; D, 

 squamous temporal bone; E, petrous temporal bone; F, orbital part of frontal bone. 



externally. The cranial surface is concave and smooth. External to the condyle is 

 the paramastoid or styloid process (Processus jugularis), a strong flattened bar of 

 bone which projects downward and backward; its external surface is convex and 

 roughened for muscular attachment. Between the root of this process and the 

 condyle is a smooth depression, the condyloid fossa (Fossa condyloidea inferior); 

 in this is the hypoglossal foramen (Foramen hyi)oglossi), which transmits the nerve 

 of like name. 



The basilar part or process (Pars basilaris) is a strong, somewhat prismatic 

 bar which extends forward from the ventral margin of the foramen magnum. It 



