REPORT ON THE SEALS. 145 



the outer surfaces of the five lower ribs below the insertion of the lateral division of the erector 

 spina;. These five origins interdigitate with the external oblique. The hindmost fibres curve 

 sharply forwards, the rest are almost longitudinal, the anterior ones most so. It passes over the 

 posterior angle of the scapula and divides into two parts ; the outer is inserted into the posterior 

 border of the abdominal part of the pectoral muscle ; the inner blends with the tendon on the 

 dorsal surface of the teres major, and is inserted with it into the inner border of the humerus, the 

 tendon being next the bone and the fleshy part of the teres above. The origin in Phoca larbata is 

 from the spines of the 5th dorsal vertebra; to the 3rd lumbar, otherwise the description is the same ; 

 and in Phoca hispida the origin is from the 4th dorsal spine, and the spines of all the remaining dorsal 

 vertebra;, from the lumbar aponeurosis as far back as the 4th lumbar spine, and for the rest as in 

 Phoca vitulina. 



In Arctocephalus gazella it arises from the lumbar aponeurosis opposite the 3rd lumbar spine as 

 far forwards as the 12th dorsal vertebra, from the spines of the 12th dorsal vertebra to the spines 

 of the 7th dorsal by muscular fibres, and from the outer middle surfaces of the 9 th to the 15 th 

 ribs. The posterior fibres do not curve sharply forwards but ascend obliquely forwards and out- 

 wards, the anterior, as in Phoca vitulina, are almost transverse. The anterior border passes outwards, 

 touching the posterior angle of the scapula above the serratus magnus, and beneath the dorsi- 

 epitrochlear division of the triceps. At the middle of the posterior border of the latter muscle it 

 divides into two parts. The inner part has the same insertion as in Phoca vitulina, and the outer 

 part blends with the thoracico-abdominal part of the pectoral muscle opposite the lateral aspect of 

 the 5th rib. The inner part brings the fore-limb backwards and turns it inwards. The outer acts 

 on the pectoral muscle. 



In the Phocina; and Arctocephalus it is supplied by dorsal and lateral cutaneous spinal and 

 lumbar nerves, and by the subscapular nerve. 



The latissimus separates into two parts about midway between its origin and insertion, forming 

 an inner and outer division. In Arctocephalus the outer division of the latissimus goes to the 

 thoracico-abdominal part, in the Phocina; to the abdominal. There are no slips coming from the 

 posterior angle of the scapula. 



The Second Laver of the superficial muscles of the back connected with the fore-limb consists 

 in the Phocina; of the levator anguli scapula;, three rhomboidei, and the atlanto-humeral ; but in 

 Arctocephalus gazella the muscles are levator anguli scapula;, two rhomboidei, and atlanto-scapular. 



The Levator anguli scapulas in the Phocina; lies below the cephalo-humeral and the trapezius. 

 It is an elongated slip and arises by an aponeurotic band from the ventral surface of the transverse 

 process of the atlas. At its origin it is situated dorsally to the atlanto-humeral, coming in contact 

 with the anterior angle of the scapula and overlapping it, to be inserted into the scapula between the 

 spine and the vertebral border, and into the vertebral border between the spine and the anterior 

 angle. The ventral surface at the origin is posterior at the insertion, giving the muscle half a 

 turn. 



This muscle in Arctocephalus gazella is an elongated triangle, and lies under cover of the 

 rhomboideus capitis over the back of the scapula. The origin was destroyed. It is inserted as in 

 the Phocina;, but falls short of the anterior end of the vertebral border of the scapula by 1 inch. 

 It moves forwards the anterior angle of the scapula and rotates it upon the back. 



(zool. cuall. exp. — part Lxvin. — 1888.) Yyy 19 



