720 B. W. KUNKEL 



Ventral to the crest runs the vena capitis lateralis which joins 

 the V. jugularis interna immediately posterior to the crista 

 parotica a short distance anterior to the fenestra metotica and 

 continues obliquely upward and forward over the lateral wall 

 of the capsule ventral to the prominentia semicircularis lateralis. 



A separate processus paroticus articulating with the crista 

 parotica, and which Gaupp has described in Lacerta, is not 

 present at any stage of Emys in the series studied. 



RELATION OF THE NERVES IN THE REGIO OTICA 



The relations of the nerves in the otic region of the skull exhibit 

 several points of considerable interest. As described by Bojanus 

 the n. glossopharyngeus passes directly through the cavity of 

 the osseous labyrinth of the ear in Emys. In the stage modelled 

 both the median and lateral walls of the cochlea are perforated 

 near their posterior ends and immediately ventral to the ves- 

 tibular portion of the capsule by the foramina glossopharyngei 

 internum and externum respectively. The n. glossopharyn- 

 geus passes from the inner foramen to the outer one in a ventro- 

 lateral direction. Between the two foramina the posterior wall 

 of the cochlea is excavated, as has been already described, to 

 form a deep groove, the sulcus glossopharyngeus, in which the 

 nerve lies with its anterior surface freely exposed in the cochlear 

 cavity. The dorsal wall of the groove is incomplete at its median 

 end because of the intersection of the cavum vestibuli with the 

 sulcus glossopharyngeus, so that the nerve has its dorsal as well 

 as its anterior surface for a short space exposed freely in the cavity 

 of the capsule. 



With reference to the nervus glossopharyngeus, the lagena 

 extends much further ventrally and posteriorly than it does in 

 Lacerta in which form the n. glossopharyngeus leaves the skull 

 together with the vagus through the fissura metotica which 

 extends quite far forwards ventral to the pars cochlearis. 



From the foramen glossopharyngei externum the nerve extends 

 in a ventro-lateral direction to the ganglion petrosum (s. glosso- 

 pharyngei) which lies ventral to the external fenestra and lateral 

 to the sulcus supracristularis. 



