DR. J. MURIE ON THE ANATOMY OF THE SEA-LION. 531 
as it enters the mandibular canal is noteworthy, in agreement therefore with the 
vascular supply to the teeth-sockets and lower lip. 
The 6th and two branches of the 7th nerve are slender compared with the 5th, and 
the facial nerve barely as thick as the 3rd at its origin. 
The three nerves which together embrace Willis’s 8th, spring distinctly separate from 
the medulla and cord. The pneumogastric is of very considerable calibre beyond its 
ganglion. Several pharyngo-laryngeal branches are distributed behind the hyoid, the 
superior laryngeal being of good size. It pierces the constrictor muscles along with the 
artery at the cleft or angle between the middle and inferior layers. The main trunk 
of the pneumogastric, as usual, proceeds to the thoracic cavity in company with the 
carotid artery and jugular vein. Pulmonary, cardiac, and gastric nerves are all remark- 
able on account of their magnitude, those to the stomach particularly so,—easily 
accounted for in an animal whose powers of rapid digestion are almost incredible. 
b. In Fore Limb.—Of the brachial plexus the external cutaneous nerve sends a sub- 
divided branch to the middle third of the belly of the biceps. Another sent off from 
the same point goes beneath that muscle, and, curving round the great aponeurotic 
tendon of the cephalo-humeral, pierces both bellies of the brachialis anticus. A nerve 
apparently connected with the above goes to the inner side, and supplies the lower- 
most triceps muscular head, and region above the elbow. 
The muscular spiral nerve is of great size; at the middle of the humerus it winds 
round the shaft as usual, but in a very shallow and ill-defined groove. The nervous 
filaments are here broadly flattened, and lie between the bellies of the second and 
third triceps muscles. Nervous twigs supply each of these muscles; one, longer than 
its neighbours, goes down to the olecranon between their fleshy fibres. As the nerve 
reaches the outer side of the arm, just above the condyloid ridge, it divides and sup- 
plies the supinator longus muscle on its outer surface, the extensor carpi radialis 
covering the nerves. Another large radial branch goes down to the under surface of 
the pronator radii teres muscle, thence towards the wrist on the pollicial aspect. 
The ulnar nerve passes round behind the internal condyle between it and the coronoid 
process, over the internal lateral ligament, and under cover of the internal anconeus. 
Below the joint it sends muscular branches to the flexor carpi ulnaris, and twigs to the 
upper head of the sublimis. The ulnar nerve continues on to the ulnar side of the 
wrist-joint, and there divides like the ulnar artery to the 5th and 4th digits. 
From the median nerve at the middle of the upper arm a twig is sent off, which 
partly goes to the flexor sublimis and partly to the adjoining muscles. Another lower 
branch supplies the pronator teres and flexor carpi radialis, piercing their bellies 
opposite the elbow-joint. Still lower (above the condyle) the anterior interosseus is 
derived. Then the main nerve, situate externally to the radial artery, continues down 
the middle of the forearm, sending twigs to the long flexors and ultimately (at the 
wrist) subdividing like the palmar artery. 
