MANDIBULAR ARTERY AORTIC ARCH 109 



into what I described, in my earlier work, as the mandibular 

 branch of the arteria carotis externa. This mandibular branch 

 of the carotis externa is apparently the buccal artery of Parker's 

 descriptions of Mustelus antarcticus. It accompanies the nervus 

 mandibularis trigemini and is prolonged, beyond the point 

 where it is joined by the lateral hypobranchial artery, toward 

 the tip of the mandible. This terminal portion of the mandib- 

 ular branch of the carotis externa is thus, in its relations to the 

 lateral hyopobranchial artery, a serial homologue of the more 

 posterior ventral branches of that artery. 



That branch of the lateral hypobranchial artery which is sent 

 dorso-posteriorly before the hypobranchial artery falls into the 

 carotis externa has a course approximately parallel to the so- 

 called arteria mandibularis. It lies slightly anterior to that 

 branch of the nervus mandibularis externus facialis which sup- 

 plies the hyomandibular line of latero-sensory organs, lies ex- 

 ternal to the nervus mandibularis internus facialis, and is sepa- 

 rated from the hyal arteries by both the musculus intermandib- 

 ularis and the musculus interhyoideus. At about the posterior 

 quarter of the length of the mandibula it receives a commis- 

 sural branch from the arteria mandibularis and then itself unites 

 with that artery, having first passed internal to, or perforated, 

 the tendon of a superficial bundle of the musculus adductor man- 

 dibulae which crosses from the mandibular to the hyal arches 

 (Fiirbringer, '03). This small and relatively unimportant artery 

 thus has all the relations to the cartilages, nerves and muscles 

 of the region that a persisting remnant of the primitive aortic 

 vessel of the mandibular arch should have, according to Dohrn's 

 descriptions of that vessel in embryos, and, as it is certainly that 

 artery (if the artery actually persists in the adult) , it can be at once 

 called the afferejit mandibular artery in order to distinguish it 

 from the so-called arteria mandibularis. 



The arteria mandibularis, running upward beween the cerato- 

 hyal and mandibula, lies internal to the musculus intermandib- 

 ularis but anterior,* and hence external, to the musculus inter- 

 hyoideus and constrictor muscle of the hyal arch. In its course 

 it passes internal to both the nervus mandibularis internus facialis 



