THE BONES. 49 



5. Ctivus, the back of the posterior border of the saddle (for Pans Varolii). 



0. 2 lateral surfaces, with Sulcus Caroticus (for the internal carotid 

 artery) ; Alae Magnse. 



y. Anterior, with crista sphenoidal. (for the lamina perpendic. of the 

 Ethmoid bone). 



J. Inferior, with rostrum sphenoidak (for the Vomer), and commence- 

 ment of the canal, pterygopalatinus. 



e. Posterior, unites with pars basilar. occipit. orifice of Vidian canal. 



b. Small wings, aloe parvce s. Processus ensiformes, triangular, flat, narrow, 

 transverse processes springing from the anterior superior surfaces of the 

 body with two roots. Connected with pars orbitalis ossis frontis. 

 Superior surface is covered by the termination of the anterior cerebral lobe. 

 Posterior border separates the anterior lateral cranial fossa from the mid- 

 dle. 



Processus clinoid. anter.: foramen opticum (for the optic nerve and ophthalmic 



artery). 

 Fissura orbitalis superior, the fissure between the great and small wings 



(for the nerv. oculomotor, trochkaris, ophthalmicus, abducens, and for the 



Vena ophthalmica cerebralis and facialis) . 



c. Great wings, alee magna, quadrangular, broad processes projecting from the 



sides of the body, with three surfaces and borders. 

 Surfaces : 



1. Internal, superficies cerebralis, concave, forms with the temporal bone the 

 centre fossa of the Basis Cranii. From before to behind we see ; foram. ro- 

 tundum (for nerv. maxillar. sup.), for. ovak (for nerv. maxillar. inf.}; for. spino- 

 sum, (for art. meningea media.} 



2. External, superficies temporalis, divided by a transverse crest into two por- 

 tions, a superior, the temporal fossa (for the muse, temporalis), and an inferior, 

 fossa zygomatica (for the muse, pterygoideus externus). On the last the inferior 

 opening of the foram. ovak and spinosum; Process, spinosus s. spina angularis 

 (for m. malleus ext.). 



3. Anterior, superf. oj-bitalis, a quadrangular plate, forms the largest portion 

 of the external wall of the orbit. The superior edge unites with the frontal 

 bone ; between the inferior border and the upper jaw the fissura orbital, 

 inferior (for Ven. ophthalmica facial., nerv. infra-orbital and subcutaneous mate). 



Borders. The three surfaces meet together in a superior broad margin, 

 which unites with the frontal bone. The orbital and cerebral surfaces unite 

 in a sharp, free, internal border, which assists in forming the fissura orbital, 

 super. The orbital and temporal surfaces in the anterior superior which joins 

 with the malar bone, and in the anterior inferior which, free and sharp, 

 assists in forming the fissura orbital, infer. The temporal and cerebral sur- 

 faces form the posterior superior border "which unites with the squamous por- 

 tion of the temporal bone, and the oblique posterior inferior border which ter- 

 minates with the spina angularis behind the foram. spinosum. 



d. Processus Pterygoidei, palatine wings, descend perpendicularly from the 

 body, one on either side, lying in the upper half free behind, and in the in- 

 ferior close to the upper jaw and palate bones. Above in their root the hori- 

 zontal Canalis Vidianus. On the anterior convex surface a furrow (sukus 

 pterygoideus), which forms, with one upon the Palate bone, the Canal, pterygo 

 palatinus. The posterior surface concave bounded by two wings ; Ma extern^ 

 (for the muscle pterygoideus externus), Ala interna with a hook, hamulus pteryg. 

 (for the circumflexus palati mottis). Between the wings, above the ossa pteryg. 



4 



