410 MABEL BISHOP 



Nerve VI. The median abducens lies in the median plane 

 below the conjoined gasserian ganglion, and enters the same 

 cranial nerve-mass dorsal to the fifth nerve (fig. 5). It is identi- 

 fied by its distal branches which innerve the external recti 

 muscles of the median eyes and a portion of the retractor bulbi. 

 At just this region the interpretation of the sections is exceedingly 

 difficult for the nerve fibers all seem to stream together beneath 

 the gasserian ganglion and become obscured by it. Therefore 

 a separate model of this area was made. 



Nerve VII. Of the two median, facial nerves, each has been 

 identified with certainty from its genu internum to the rostral 

 cranial nerve-mass, but I was not able to trace the fibers through 

 the mass (see Central connections of the cranial nerves and the 

 associated fiber tracts) . The peripheral fibers are directly related 

 to the median isolated ganglion and are considered in connection 

 with it. 



Nerve VIII. No peripheral fibers of median acoustic nerves 

 were identifiable, although conjoined cartilage of the median 

 internal ear capsules is present. 



Nerve IX. Immediately below the abducens and parallel 

 with it in the median line there is another nerve of almost twin 

 appearance, which however, emerges from the caudal cranial 

 nerve-mass (fig. 5) . It may be a median ninth, but again certain 

 identification is not possible, since its peripheral distribution is 

 indefinite. 



Ventral to these abruptly terminated nerves there are still 

 other fine, detached fibers scattered through the tissue on either 

 side of the midline, some indicating a course to the juxtaposed 

 external surfaces of the head members, i.e., toward the median 

 line of the monster. The identification of these branches is 

 little more than guesswork, however, for neither cranial nor 

 peripheral connections were seen. 



Nerves X, XI, and XII. Just caudal to the uncertain ninth 

 nerve, a shorter one arises, probably the vagus (fig. 5). Behind 

 this one, short stumpy roots emerge from the nerve-mass, but 

 end abruptly in near-by tissue. They suggest the remaining 

 median cranial nerves, accessorius and hypoglossus. This 



