Bones of the Skull. 



Ala mat; iia | Processus clinoideus anterior 



Dorsum sellae Facies cerebralis 



Ala parva , Foramen rotundum i 



Proc. vagin. : ' ; \ 

 Canal, pharyng. i 

 Sulcus caroticus , 



Angulus 

 parietalis 



Processus pterygospinosus 

 [Civinini 



Processus 

 pterygoidens 



- Sulcus tubae auditivae 



Spina angulads 



Hamulus 

 pterygoideus 



Lingula sphenoidalis 

 Fossa scaphoidea 



? Fossa pterygoidea 



" Lamina lateralis 



Fissura pterygoidea 

 Sulcus hamuli pterygoidei 



6. Sphenoid bone, os sphenoidale, from behind. 



The alae parrae ossis spheuoidalis (small icings of the sphenoid bone) (see also 

 Figs. 4, 5, 63 66, 69 and 70) arise from the anterior superior part of the lateral surface of 

 the body by two roots which surround the foramen opticum (for the a. ophthalmica ; n. opticus). 

 They are smooth thin plates of bone which present a superior and an inferior surface; the in- 

 ferior forms with the orbital surface of the large wing (cf. p. 5) the fissura orbitalis superior. 

 The anterior margin , a part of the mar go frontalis , is serrated and lies upon the posterior 

 margin of the pars orbitalis oss. frontalis (sulura spheno frontalis) ; the posterior margin is 

 smooth and runs out medianward into the strong processus clinoideus anterior. 



The processus pterygoidei (pterygoid processes) (see also Figs. 5, 59, 60 and 65 68) 

 extend from the point of union of the body and the large wing downward. They are com- 

 posed of two plates: the shorter and broader, lamina lateralis proc. pteryg. (lateral surface 

 for the m. pterygoideus externus); the other narrower and longer, lamina medialis proc. pteryg.. 

 The two plates unite anteriorly at an angle, in front of which there extends from above down- 

 ward the sulcus pterygopalatinus ; behind, the plates diverge and form the deep fossa ptery- 

 goidea (for the m. pterygoideus intemus) ; between the two below is a notch with jagged borders, 

 the fissura pterygoidea, in which is received the proc. pyramidalis oss. palatini, and over which 

 the proc. pterygoideus sometimes lies against the fades infratemporalis maxillae (see Fig. 67). 

 The lamina medialis runs out below to form the hamulus pterygoideus (0. T. hamular process) 

 which is curved lateralward. This process is concave on its lateral surface and is covered with 

 cartilage forming the sulcus hamuli pterygoidei (for the tendon of the m. tensor veli palatini). 

 Passing downward over the root of the lamina medialis on the posterior surface is the fossa 

 scaphoidea (for the origin of the m. tensor veli palatini). Lateralward from this, encroaching 

 upon the medial surface of the spina angularis lies the sulcus tubae auditivae (for the pars 

 cartilaginea tubae auditivae). The lamina medialis gives off from its root the processus vagi- 

 nalis, a small process which extends medianward toward the body; on the inferior surface of 

 this process, either as a closed canal or as a groove which is closed by the proc. sphenoidalis 

 oss. palatini , is the canalis pharyngeus (0. T. pterygopalatine canal) (for a small branch of 

 the a. sphenopalatina ; rr. nasal, post. sup. lat. gangl. sphenopalat.) ; between the inferior surface 

 of the body of the bone and the processus vaginalis, a canal is sometimes present, the canalis 

 basipharyngeus (for the rr. nasal, post. sup. lat. gangl. sphenopalat.). Constantly present, passing 

 through the root of the pterygoid process in a sagittal direction, is the canalis pterygoideus 

 [Vidii] (0. T. Vidian canal) (for the a. et vv. canal, pteryg.;- n. canal, pteryg.); its posterior 

 opening lies below the lingula sphenoidalis, its anterior opening upon the sphenomaxillary 

 surface, medianward and below the foramen rotundum. 



