123 



dorsal aorta opposite or slightly posterior to the point where that 

 artery is joined by the efferent artery of the first branchial arch. 

 Running forward and downward it sends a branch through the facialis 

 canal through the hyomandibular, with the nervus facialis, and then 

 itself traverses the trigemino-facialis chamber of the skull. Having 

 issued from that chamber it runs downward and forward along the 

 hind edge of the orbit, sending two or more branches to the tissues 



s.ahy 



Ihbr ' aal 

 e'al 



mhbf 



eaW 



Fig. 3. Lateral view of the pseudobranchial, branchial and carotid arteries in 

 Gadus aeglefinus ; the dorsal aorta swung upward and appearing as in dorsal view. 



and muscles of the region, and then continues onward and terminates 

 in the mandible. 



In Gadus aeglefinus (Figs. 3 and 4) I find the circulus cephalicus 

 and related arteries practically as given by Johannes Müller (1839) 

 in Gadus callarius (morrhua), the only difference being that, in my 

 specimen, a single median artery arises from the extreme anterior 

 end of the circulus instead of the two arteries there shown by Müllee. 

 MtJLLER in his Fig. 3 Tab. IV shows two pairs of arteries arising from 



