479 



2715. The neural arch of the parietal vertebra, with the temporal and malar bones. 



The centrum (basisphenoid) has coalesced with the neurapophyses (alisphenoids), which 

 are separated from the neural spine (parietals) by the intercalated squamosals. The pterygoid 

 processes are long, much expanded and excavated anteriorly, and are perforated at their base. 

 The alisphenoids are notched at their posterior and anterior margins, but are not perforated. 

 The apex of the petrosal is deeply grooved by the entocarotid. The post-tympanic, or con- 

 nate mastoid, process meets the post-glenoid process below and circumscribes the meatus ex- 

 ternus. The tympanic completes the lower wall of the meatus, expands into a large bulla, 

 and has coalesced with the petrosal. The stylomastoid foramen is between the mastoid and 

 the base of attachment for the stylohyal developed by the tympanic. The squamomastoid 

 has not yet coalesced with the petrotympanic. 



2716. The neural arch of the frontal vertebra, with the neurapophyses of the nasal 

 vertebra and portions of the coalesced capsule of the olfactory sense-organ. 



The frontal neurapophyses (orbitosphenoids) have coalesced with each other at their base, 

 and also with those of the nasal vertebra (laminae mediae sethmoidei) : they are perforated 

 by the optic foramina and by those for the nerves and vessels of the orbit. The portions of 

 the olfactory capsule closing the anterior orifice of the cranial cavity form extensive ' cribri- 

 form' plates. 



2717. The atlas. 



It consists of the two neurapophyses and the hypapophysis, which are connected together 

 by dried fibro-cartilages : the neurapophyses are united to each other above by suture ; the 

 right one developes both a diapophysis and a parapophysis, which processes circumscribe the 

 arterial foramen, and meet, but are still distinct. The left neurapophysis developes only the 

 diapophysis, which is imperforate. Both neurapophyses are grooved, and the left one per- 

 forated, near the upper and anterior border, by the vertebral artery. 



h 



2718. The dentata and three following cervical vertebrae. 



The centrum of the first cervical vertebra is still distinct, but is attached to that of the second 

 vertebra, of which it forms the odontoid process. The neurapophyses of each of the present 

 vertebrae have coalesced above, but are separate from each other and from then- respective cen- 

 trums below : they develope long diapophyses and short parapophyses from the outer side of 

 their base. The pleurapophyses, which are afterwards ossified continuously with the par- 

 apophyses, here present the condition of dried cartilages. 



2719. The sixth cervical vertebra. 



It shows the proportions of the body contributed by the still separate neurapophyses : the 

 terminal epiphyses are cartilaginous. 



