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



In the Phocina? and Arctoccphalus the levator is supplied by the spinal accessory anterior to the 

 scapular spine and by the cervical nerves. 



Rhomboidci. — There are three rhomboidei in the Phocinte, and these are named — a. PJiom- 

 boideus capitis ; b. Ehomboideus cervicis ; c. Pdiomboideus dorsi. 



The Ehomboideus capitis is a long narrow band, lying below the cephalo-humeral and the 

 trapezius. It arises from the superior posterior angle of the parietal bone, to the inner side of the 

 origin of the temporal muscle, and from the margin of the adjacent occipital bone. Opposite the 

 spine of the scapula at the vertebral border, it passes beneath the rhomboideus cervicis, and is 

 inserted into the ventral side of the cartilaginous plate of the scapula, near its posterior angle, 

 between the insertions of the serratus. Professor Humphry has not described two separate 

 muscles coming from the neck and head, but one, and to this the name rhomboideus minor is given. 

 In the Phocina? it is supplied by filaments from the cervical nerves. 



The Ehomboideus cervicis arises from the forward fascial prolongation of the ligamentum nucha? 

 opposite the occipital bone, and from the ligamentum nuchee. Until the fibres reach the middle of 

 this ligament, the muscle is a slender band, then it becomes broader, and the fasciculi are obliquely 

 directed to the base of the scapula. It is inserted into the vertebral border of the scapula 

 posterior to the spine, and into the vertebral border of the cartilaginous plate. Some of the 

 hindmost fibres run into those of the serratus magnus at its insertion. In the large PJwca 

 vitulina the origin is as far back as the 2nd dorsal vertebra. This muscle is not specially noted 

 by Humphry, but named rhomboideus minor with the last muscle. In Phoca vitulina it is supplied 

 by the 4th cervical, and in Phoca barbata and Phoca hispida from the 5th cervical. 



The Ehomboideus dorsi is a small triangular muscle lying between the scapula and the serratus 

 magnus. It arises from the first four dorsal spines, and from the supraspinous ligaments. The 

 fibres go towards the posterior angle of the scapula on its ventral surface. It is inserted into the 

 axillary border of the cartilaginous plate, and to a very small extent into the axillary border of 

 the scapula. In the large Phoca vitulina the origin is from the 2nd dorsal vertebra to the 4th. 

 There is a slight difference in Phoca barbata, it arises from the 3rd, 4th, and 5th dorsal vertebrae. 

 To this muscle Professor Humphry has given the name rhomboideus major. In Phoca vitulina and 

 Phoca hispida it is supplied by a lateral nerve from the 1st intercostal space ; in Phoca barbata 

 by nerves from the 3rd and 4th, and 4th and 5th, intercostal spaces ; in the large Phoca vitulina by 

 a large dorsal branch passing between the 2nd and 3rd ribs. 



In Arctoccphalus gazella, instead of three distinct muscles, there are only two, but these have 

 three insertions. They are the rhomboideus capitis (et scapularis) and the rhomboideus dorsi. 



Bhomboidcus capitis (ct scapularis). — As the attachments of this muscle are vastly different from 

 the corresponding muscle in the Phocime, I have added " et scapularis " to emphasise the peculiarity. 

 The origin was mutilated. The fibres proceed backwards and slightly outwards, and cover half 

 the dorsal surface of the scapida anterior to the spine. It is inserted into the inner half of the 

 scapular spine, into the posterior lip, and into the scapula between the spine and the vertebral 

 border. Some fibres unite with those of the atlanto-scapular just anterior to the spine. 



The Ehomboideus dorsi is of a rhomboid shape. It arises from the spine of the 7th cervical, 

 and then from the same spines as in Phoca vitulina. There is no division at the origin, but 

 as the fibres approach the vertebral border of the scapula they collect into two parts. The 

 anterior part has the same insertion as the rhomboideus cervicis of Phoca vitidina, but it 



