GREGORY: NOTHARCTUS, AN AMERICAN EOCENE PRIMATE 



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posterior wall of the tympanic fossa; it bends over the cochlea, and passing forward and inward pierces 

 the basisphenoid, passing obliquely forward and inward through a canal which may be named canalis 

 caroticus basisphenoidei, and which is homologous with the carotid canal of Marsupials, Centetes and 

 Lemur. Issuing in the mid-cranial fossa lateral to the sella turcica the art. promontorii joins the main 

 cerebral trunk (art. connnunicans posterior, art. cerebri). 



Fig. (35. ('oiirse of the internal carotid ami its branches in Erinaccus. 



1. Oblique inferior aspect. The internal carotid (rc])resentccl liy a coi)pcr wire) enters the bulla on its posteromedial side and 

 almost immediately divides into an arteria promontorii (medial fork) and an arteria stapedia (lateral fork). After traversing 

 the stapes (not shown here) the arteria stapedia turns forward and gives rise to the ramus inferior, which runs forward to the 

 orbit. Just before leaving the tympanic cavity the ramus inferior gives off the ramus superior. The bristle indicates the 

 position of the canalis facialis (aqueductus Falopii). 



2. Interior of brain-case, showing the course of the ramus superior along the medial surface of the endocranial wall, i-unning forward 

 through the foramen cranio-orbitale to the orbit. The bristle passes through tlie hiatus Falopii into the facial canal. 



Fig. (iO. Auditory region of Tiijiaid. After \'an Kampen. 

 6, bulla, e.t., entotymiiaincvuii, ///., pars mastoidea, p.p. pars petrosa, «./., annulus, /.cc, foramen caroticum posticum, ex., canalis 

 caroticus. 



