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traverses a notch in the hind edge of the lateral wall of this groove, 

 the cartilage and fibrous tissue together forming a foramen through 

 which the artery passes to join the internal carotid. Slightly posterior 

 to this point the pharyngeus glossopharyngeus has separated into two 

 parts, and one of these parts now perforates the ventral, fibrous wall 

 of the internal carotid canal to join the two arteries in that canal, 

 the other branch of the nerve remaining outside the canal. The 

 ventral, fibrous wall of the canal now becomes partly cartilaginous in 

 my larvae, and judging from Bridge's figures it must be wholly cartila- 

 ginous in the adult. Opposite the point where the efi'erent pseudo- 

 branchial artery pierces the side wall of this canal, the mesial wall 

 is perforated by a short canal which transmits the ramus palatinus 

 facialis. This nerve, as it enters the internal carotid canal, separates 

 into two parts both of which run forward in the canal, one of them 

 sending a communicating branch to the ramus pharyngeus glosso- 

 pharyngeus. 



Slightly anterior to the point where the palatinus facialis enters 

 the internal carotid canal, the internal carotid and afferent pseudo- 

 branchial arteries leave the groove or canal on the ventral surface 

 of the skull and enter a canal that runs forward and mesially 

 ventral to the large canal, or foramen, that transmits the trige- 

 minus, the associated lateralis nerves and the abducens from the 

 cranial cavity into the orbit, a small foramen putting the two 

 canals in communication as they cross each other. As the two arteries 

 run forward in this part of their canal they come into contact and 

 coalesce to form for a short distance a single oblong vessel. A part 

 of the efferent pseudobranchial portion of this large vessel here joins 

 the internal carotid, the remainder of this pseudobranchial portion 

 then immediately separating from the larger vessel as the ophthalmica 

 magna artery. This small artery turns dorso-laterally, traverses the 

 foramen that puts the internal carotid and trigeminus canals in 

 communication, and enters the latter canal. There the ophthalmica 

 magna runs forward and reaches and enters the eyeball posterior to 

 the nervus opticus. The internal carotid artery continues onward in 

 its own canal, and soon enters the cranial cavity. There it separates 

 into anterior and posterior cerebral arteries and an optic artery. The 

 posterior cerebral arteries of opposite sides are connected by a 

 commissural vessel that passes dorsal to the saccus vasculosus. The 

 optic artery escapes from the cranial cavity with the nervus opticus 

 and separates into two parts, both of which enter the eyeball, one of 

 them with the opticus and the other at some distance anterior to 

 that nerve. 



