Macalister— 0;j Ligamentum Pterygospinosum. 203 



spinosus of Luschka (Miiller's Arcliiv., 1853), traversed a well-marked 

 groove from the oval to the spinous foramen, and the tip of the spina 

 angularis was nearly separated from its base by a suture. 



2nd. The presence of a tooth on the external pterygoid plate 

 (figs. 6 u), as the only ossified part of the ligament ; this I have seen very 

 large, and in one negro skull (tribe unknown) from the Gold Coast, it 

 appeared as a round tubercle near the base of the external pterygoid 

 plate, but separate from that plate. Several instances of this tooth 

 were coexistent with a very thin oblique lamellar septum between 

 the oval and spinous foramina, and in one case the two foramina were 

 not separated, while on the right side of another the oval foramen 

 communicated with the pterygo-sphenoidal fissure. The spinous 

 foramen in another specimen was in the line of the spheno -petrosal 

 suture. Cases of this kind occurred in twenty skulls. 



3rd. Cases of the presence of a second distinct tooth on the 

 pterygoid plate. This is noticed in Theile's Muskellehre, p. 68, 

 where such a tooth may be below the primary one, is always flatter 

 and weaker, and rarely has a ridge like the prominent rib on the inside 

 of the ectopterygoid plate, which crosses the upper part of the ptery- 

 goid fossa to strengthen the primary tooth ; sometimes a second 

 accessory tooth higher than the primary one is present, but this 

 usually coexists with the spur to be described below (Xo. 5), and is for 

 the accessory ligament. The lower tooth is for the attachment of the 

 external pterygoid muscle. Cases of the existence of this second tooth 

 existed in nine skulls. 



4th. The coexistence with the fore-mentioned tooth or teeth of a 

 forward-dii'ected spur on the spina angularis sphenoidalis was noticed 

 in eighteen skulls : sometimes this is of very large size, projecting 

 towards the j)terygoid tooth, but always separated by an interspace 

 (figs. 1,2, l^p). This very often existed with a double pterygoid tooth, 

 and in one instance where it was present there was no pterygoid tooth : 

 in one case there was no spina angularis on the sphenoid, but a process 

 sundered fi'om the anterior and internal end of the vaginal ridge (spina 

 petrosa) took its place. This spina petrosa is not rare, either as an angle 

 of the vaginal ridge or as an independent spur, and it often contributes 

 with the spina angularis to give origin to the internal lateral ligament of 

 the lower jaw. 



5th. The existence of a spina accessoria external to the foramen 

 ovale, and separated from the spina angularis by the foramen spinosum, 

 has been before referred to as giving attachment to the ligamentum acces- 

 sorium pterygo-spinosum (figs. 1, 2, 9 a), and it may be present and dis- 

 tinct even though the two ligaments are united. This is a very frequently 

 present spine, as it exists in forty-one skulls. I have even found this 

 present in the skull of a three-year-old child. In some of these it was 

 only present as a minute rudiment, but in others it was long, and formed 

 nearly a loop with a long pterygoid tooth. In a Chinook pkull this 

 coexisted with a fine lamellary septum between the foramina ovale and 

 spinosum. In a Mandingo skull it coexisted with a strong spina petrosa. 



