REPORT ON THE SEALS. 229 



anterior ones long and chiefly tendinous, the posterior more muscular. They are inserted into the 

 posterior borders of the 11th to the 15th ribs, into the zygapophyses and anapophyses of the 11th 

 to the 15th vertebras, into the anapophyses of the 1st to the 10th dorsal vertebrae, and into the 

 tips of the dorsal tubercles of the transverse processes of the 3rd to the 7th cervical vertebrae. 

 Some fibres of this muscle seem to take origin along the internal borders of the vertebrae. 



The Transversalis ecrvicis or colli in Phoca vitulina is in part a continuation of the longissimus 

 dorsi, and branches off from it at the 6th rib. It also arises by muscular fibres from the dorsal 

 surfaces of the transverse processes of the 1st to the 5th dorsal vertebras, to the inner side of the 

 tendons of insertion of the longissimus dorsi into the same processes, which if developed would be 

 the anapophyses, and from the anterior halves of the anterior zygapophyses of the 5th, 6th, and 7th 

 cervical vertebras and the 1st dorsal. It forms in conjunction with the part coming out of the 

 longissimus dorsi a muscular band which advances towards the cervical region, and there lies 

 between the digitations of the serratus magnus on its outer side and the trachelo-mastoid on its 

 inner, and is inserted by five tendinous slips into the dorsal tubercles or divisions of the transverse 

 processes of the 3rd to the 7th cervical vertebrae. In the large Phoca vitulina it arises in addition 

 from the transverse processes of the 6th to the 10th dorsal vertebras. 



In Arctoccphalus it is a prolongation of the longissimus, and can only be regarded as the 

 part of the longissimus which lies in the region of the neck and is described with it, because there 

 is no slip given off from it as in Phoca. 



The Trachelo-mastoid in Phoca vitidina lies between the complexus and the transversalis cervicis. 

 It arises from the anterior and posterior zygapophyses of the 3rd to the 7th cervical vertebras, and 

 the surfaces of the vertebras between the articular surfaces. It divides into two parts ; the portion 

 arising from the 3rd, 4th, and 5th vertebras is inserted into the posterior edge of the transverse process 

 of the axis ; the rest goes to the cranium, and is inserted into the mastoid process. It is supplied 

 by the external division of the 2nd and 3rd cervical nerves. 



In Arctoccphalus it is called by Murie splenius colli, and arises from the 3rd, 4th, 5th, 6th, and 

 7th cervical vertebras between the posterior zygapophyses and the hyperapophyses, and from the dorsal 

 surfaces of the laminas between each vertebra, and from the sides of the roots of the 1st, 2nd, 3rd, 

 and 4th dorsal spines. The last two cervical origins blend with the complexus. It courses anteriorly 

 below the outer border of the splenius, and is inserted by a narrow tendon into the inferior part of the 

 occipital ridge behind the external auditory meatus posterior to the insertion of the splenius. 



The Spinalis dorsi is only found in Arctocephalus. It lies between the neural spines and the 

 longissimus dorsi; the dorsal surface is muscular as far back as the 12th rib, from this to the 14th 

 rili it is tendinous and appears continuous with the longissimus; but, by scraping away the muscular 

 fibres which arise from the neural spines, a set of tendons is reached which appears to be the 

 aponeurosis of the longissimus, but can with a little care be parted from it. It arises by muscular 

 fibres and by long tendinous slips ; the fibres spring from the sides of the neural spines from the 

 9th to the 12th dorsal vertebras, the long tendinous slips from the metapophyses of the 11th to the 

 14th dorsal vertebras. The muscular fibres are sparse and thin at the posterior extremity, but 

 deepen and expand anteriorly; the tendons of origin lose themselves on the under surface of the 

 muscle. It is inserted by small tendinous slips into the sides and tips of the neural spines from 

 the 1st to the 8th dorsal vertebras ; but the 1st, 2nd, and 3rd vertebras also have fibres inserted 

 into them. A large muscular slip is continued into the cervical region, forming the spinalis colli. 



