144 THE VOYAGE OF H.M.S. CHALLENGER. 



obliquely forwards and upwards, and comes into close relation with the cervical aii- sac. 

 It passes into the foramen of the transverse process of the first dorsal vertebra,^ and 

 thereafter extends forwards, lying in the bony canal formed by the transverse pro- 

 cesses of the cervical vertebrae as far as the cephalic extremity of the neck. Its exact 

 mode of termination I could not make out in any species, with the single exception of 

 Spheniscus mendiculus, because of the impossibility of completely injecting it. In the 

 species named, however, I found that the vertebral artery after escaping from the bony 

 canal between the second and third cervical vertebrae, terminated by inosculating with 

 the occipital artery. In all probability, therefore, in the Penguins as in the majority of 

 birds, according to Barkow,^ this is the normal mode of termination of the vertebral artery. 

 The Subcutaneous Cervical Artery ^ comes off from the common carotid close to the 

 vertebral artery. It passes obliquely forwards and outwards, and crossing the jugular 

 vein reaches the deeper surface of the panuiculus carnosus muscle. Here it applies itself 

 to the vagus nerve, and accompanies it together with the jugular vein as far forward 

 a? the posterior extremity of the mandil)le. Having reached this point, the artery passes 

 inwards, resting upon the lower surface of the rectus capitis anticus muscle, and 

 terminates by inosculating with a branch of the external carotid. 



(A) Tlie External Carotid Artery 



Is very short. In the King Penguin it does not exceed ^th of an inch in length. 

 From its origin it passes obliquely outwards to gain the inner surface of the posterior 

 extremity of the mandible, where it divides into three terminal branches. These branches 

 are the lingual, the palatine, and the anastomotic. Of these the two former pass 

 forwards while the latter passes backwards. 



(a) TJie Lingual Artery at its origin is superficially placed. It extends from the 

 external carotid almost horizontally forwards, lying along the inner side of the corre- 

 sponding half of the lower jaw bone. At first it lies under cover of (above) the cornu of 

 the hyoid bone, but farther forward it lies in the interval between the ramus of the lower 

 jaw bone on the outer, and the hyoid cornu on the inner side. Towards its termination 

 it rests upon the surface of the mylo-hyoid muscle, and having reached the s}Tnphysis of 

 the lower jaw bone, inosculates with its fellow of the ojiposite side. The lingual arteiy, 

 close to its origin, gives off a branch of some size which passes to supply the walls of the 



1 I consider the vertebra referred to to Ije the first dorsal, because the anterior bar of its transverse process is 

 moveably articulated, both with the body of the vertebra and with the extremity of the posterior bar of its transverse 

 process. The anterior bar of this transverse process thus forms a rudimental rib. By some authors this vertebra is 

 considered to be the last memlier of the cerv'ical series. 



2 Meckel's Archiv fiir Anatomie nnd Physiologie, 1829, p. 305. 



3 The arrangement of this artery in the Hombill is carefully described by Ottley in the Proc. Zool. Soc, 1879. 

 In that bird the subcutaneous cervical artery inosculates with the vertebral artery, whereas in the Penguin it anasto- 

 moses with the external carotid. Ottley terms this artery the " arteria comes nervi vagi." 



