28o ■ ALUS. [Vol. XVIII. 



muscle. The remainder of the nerve then turns outward and 

 reaches the inner surface of the opercukim, where it pierces the 

 opercular bone and could npt be further traced. The branch of 

 the nervus linese lateralis penetrates the septal membranes that 

 cover the outer surface of the anterior end of the trunk muscles, 

 passes mesial or posterior to the posterior process of the intercalar, 

 and then mesial to the posterior process of the squamosal. There 

 it breaks up into four parts, one of which supplies organ 13 infra- 

 orbital, which lies in the hind end of the squamosal; one organ 15 

 in the anterior end of the suprascapular; and the other two the 

 three organs in the extrascapular. These two branches, arising 

 one from the vagus root and the other from the root of the linese 

 lateralis, are thus the supratemporal branches of their respective 

 nerves, but they are not, in their distribution, the exact homo- 

 logues of the corresponding branches in Amia. 



Immediately outside the vagus foramen the first vagus nerve 

 separates from the rest of the truncus and enters a ganglion, which 

 is wholly separate and distinct from the ganglia formed on the 

 other parts of the nervus. These latter ganglia are more or 

 less fused with each other, the second ganglion being partly fused 

 with the third, and the third one still more completely fused with 

 the fourth. All of the ganglia lie internal to the levatores arcuum 

 branchialium, and ventral to the anterior edge of the trunk mus- 

 cles. The first intermuscular septum has its atachment to the 

 skull immediately dorsal to the vagus foramen ; the antero-ventral 

 edge of the second septum lying along the hind edge of the fora- 

 men, and extending forward a slight distance both dorsal and 

 ventral to it. 



In the later dissections made by Dr. Dewitz he was able to 

 separate two bundles of fibers from the ventral surface of the 

 vagus ganglion, the bundles having their origins from the root 

 of the nervus and running distally, across the ventral surface of 

 the ganglia, to the trunks of the nerves beyond them. Mr. 

 Nomura, in his dissections, did not find these bundles so distinctly 

 differentiated, this difference in the results obtained being doubt- 

 less due to the difference in the way the specimens were preserved 

 and treated. One of the two bundles found by Dr. Dewitz arose 

 from the root of the first vagus, just as, or before, that nerve 



