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The foramen rotundum and the foramen ovale are situated close to- 

 gether, within a common transversely oblong depression. The carotid 

 canal opens into the outer side of the commencement of this wide 

 channel, which conducts the great fifth pair of nerves to the outlets of its 

 two chief divisions. The petrous bone projects into the cranial cavity 

 in the form of an angular process with three facets : the foramen audi- 

 torium internum and the aqueductus vestibuli, are situated on the 

 posterior facet. Immediately behind the os petrosum is the foramen 

 lacerum jugulare, situated at the point of convergence of the vertical 

 groove of the lateral sinus with a groove of similar size continued for- 

 wards from above the anterior condyloid canal. The plane of the in- 

 ternal opening of this canal is directed obliquely inwards and backwards, 

 and the lateral wall of the foramen magnum behind the foramen condy- 

 loideum slopes outwards to the edge of the condyle. Immediately 

 internal to the foramen condyloideum is a small vascular foramen con- 

 ducting a branch of the basilar artery into the condyloid canal, for the 

 nourishment doubtless of the great lingual nerve. 



There is a remarkable cavity situated immediately behind the tympanic 

 bone of nearly a regular hemispherical form, an inch in diameter. The 

 superficies of this cavity appears not to have been covered with articular 

 cartilage, for it is irregularly pitted with many deep depressions, and 

 probably afforded a ligamentous attachment to the styloid element of a 

 large os hyoides. With this indication of the size of the skeleton of the 

 tongue, is combined a more certain proof of the extent of its soft and 

 especially its muscular parts, in the magnitude of the foramen, for the 

 passage of the lingual or motor nerve. This foramen (the anterior con- 

 dyloid) in the present specimen is the largest of those which perforate 

 the walls of the cranium, with the exception of the foramen magnum : 

 it is fully twice the size of that which gives passage to the second divi- 

 sion of the fifth nerve ; its area is oval, and eight lines in the long 

 diameter, so that it readily admits the passage of a man's little finger. 



Some idea of the size of the lingual nerve and of the organ it was 

 destined to put in motion, may be formed, when it is stated that the 

 foramen giving passage to the corresponding nerve in the Giraffe — the 



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