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that comes down from the trigemiDo-facialis chamber corresponds to 

 the internal jugular of Allen's (1905) descriptions of the Loricati, 

 that part of the vein that remains in the trigemino - facialis chamber 

 being the external jugular and probably including the orbito- nasal 

 component, though this was not traced. 



The external carotid, having entered the trigemino - facialis 

 chamber, runs forward with the trigeminus and lateralis nerves, and 

 entering the orbit breaks up into several branches which I have not 

 further traced. 



The internal carotid continues forward in a V-shaped grove on 

 the lateral edge of the parasphenoid, as shown in Pollard's figures, 

 there being accompanied by the internal jugular vein, and soon passes 

 across a foramen that leads into the pituitary fossa of the cranial 

 cavity. Through this foramen the internal jugular receives a vein 

 that comes from the pituitary body, the foramen being found, in the 

 adult fish, as a perforation of the sphenoid bone of Traquair's de- 

 scriptions, near its ventral edge. Traquair apparently did not find 

 this pituitary foramen, and his descriptions and those of later in- 

 vestigators do not at all agree either as to the number of foramina 

 that perforate this part of the sphenoid or as to what they respectively 

 transmit. Traquair gives two foramina, one of which is said by him 

 to transmit the nervus trochlearis, and the other the oculomotorius, 

 abducens and ophthalmicus superficialis trigemini. Van Wijhe (1882) 

 finds these same two foramina but says that one transmits the tro- 

 chlearis and the other the oculomotorius and the ramus ophthalmicus 

 profundus trigemini. Bridge (1888) also finds the same two foramina, 

 but according to him one transmits the trochlearis and the other the 

 oculomotorius alone. And finally Pollard (1892) shows but one for- 

 amen in this region, and it is shown as being traversed by the oculo- 

 motorius and the ramus ophthalmicus profundus. A foramen for the 

 trochlearis Pollard does not show, and his Figure 7, giving the 

 peripheral distribution of the cranial nerves, would lead one to suppose 

 that he had not even with certainly identified the nerve. 



In my small specimen I find, in the region of these foramina, 

 five separate perforations of the cartilaginous side wall of the cranium. 

 Two of these foramina lie near the dorsal edge of the orbital wall 

 and transmit, each, a branch of the external jugular; a third lies 

 near the ventral edge of the orbital wall and transmits the pituitary 

 vein above referred to; the other two being intermediate in position 

 and being quite undoubtedly the foramina 3 and 4 of Traquair's 

 figures. Foramen 4 transmits the nervus trochlearis alone, foramen 3 



