REPORT ON THE SEALS. 231 



into the sacral portion of the multifidus. In the sacral region they arise by a tendinous slip from 

 the zygapophysis of the 4th sacral vertebra, from the zygapophysis of the 3rd sacral by a very short 

 tendinous slip, from the dorsal surface of the sacrum between the neural spines and the zygapo- 

 physes, and from the fascia covering it. The mass thus formed and strengthened by the caudal 

 slip joins anteriorly the lumbar portion, and is inserted by muscular fibres into the neural spines 

 and the contiguous dorsal surfaces of the sacral laminae, and by tendinous slips into the neural 

 spines of the 4th and 5th lumbar vertebra;. In the lumbar region the fibres arise by broad 

 tendinous slips from the anterior zygapophyses of the 1st sacral and all the lumbar vertebrae, 

 from the posterior zygapophyses and dorsal surfaces of the laminas of all the lumbar vertebra?, 

 and from the fibrous covering above the muscles. These fibrous slips from the anterior zygapo- 

 physes join the muscle on the under surface of its outer border. They are inserted by tendinous 

 slips along its inner border into the posterior aspect of the dorsal tips of the neural spines of the 

 12th to the 15th dorsal vertebras, into the corresponding part of the 1st, 2nd, and 3rd lumbar 

 vertebras, and by muscular fibres into the sides of the neural spines of the same vertebras. In 

 the dorsal region the fibres arise from the metapophyses of the 8th to the 15th dorsal vertebrae, 

 from the dorsal surfaces of the laminae, as far forwards as the 8th or 9th dorsal vertebra, and are 

 inserted in the same way as the lumbar portion, into the 1st to the 11th dorsal vertebrae. From 

 the 10th to the 15th dorsal spines the fibres of the superficial layer are intimately connected with 

 the longissimus dorsi, and have origin from the under surface of the dorso-lumbar fascia, as far- 

 forwards as the 14th dorsal vertebra. The tendons of origin from the 6th to the 15th vertebrae 

 are shared between the longissimus and the multifidus ; the cervical portion is an offshoot from the 

 dorsal about the level of the 8th rib, and forms long slips which are inserted into the neural spines 

 of the 3rd to the 7th cervical vertebrae. 



The deep layer of fibres of the oblique rotator in Phoca vitulina. The first muscle arises from 

 the 3rd to the 5th cervical vertebrae from the posterior zygapophyses, and is inserted into the 

 posterior zygapophysis of the axis. The second arises from the posterior zygapophyses of the 4th 

 to the 6th cervical vertebrae to the inner side of the 7th, and is inserted into the posterior border 

 of the lamina of the 3rd cervical vertebra. The third arises from the same parts of the 5th to 

 the 7th, and is inserted into the corresponding part of the 4th cervical vertebra. The fourth arises 

 from the laminae of the 6th and 7th cervical and the 1st dorsal vertebra 3 , and is inserted into the 

 dorsal surface of the same portion of the 5th cervical vertebra. The fifth arises from the posterior 

 zygapophysis of the 1st dorsal vertebra, from the dorsal surface of its lamina, and from the dorsal 

 surface of the lamina of the 7th cervical, and is inserted into the dorsal side of the spine of the 6th 

 cervical vertebra. The sixth arises from the transverse process of the 2nd dorsal, from the posterior 

 zygapophysis of the 1st dorsal, and is inserted into the spine of the 7th cervical. In the dorsal 

 region they are not so oblique as in the cervical region. One arises from the zygapophyses of the 

 2nd to the 4th dorsal vertebrae, and is inserted into the spine and lamina of the 2nd dorsal vertebra, 

 and so on to the 10th dorsal vertebra, the last muscle only having origin from one vertebra. The 

 cervical muscles are all oblique, the dorsal are oblique and transverse, and all are imbricated. 



'The superficial layer of the oblique rotator muscles in Arctoceplialus is well developed. The 

 cervical muscles are much longer than the dorsal, the first and most anterior a/rises by three slips, 

 from the dorsal surface of the lamina and the posterior zygapophysis of the 3rd cervical 

 vertebra, from the hyperapophysis of the 4th cervical, and from the same part of the 5th cervical 



