DR. J. MURIE ON THE ANATOMY OF THE SEA-LION. 583 
plane of ligament, which from attachments may be termed ulno-carpal (w.c), rises higher 
up and from the radial border of the ulna, and, with a fastening to the pisiform, forms 
a deep sheet attached to the several carpal bones, and intermingles with the so-called 
anterior carpal ligament. A transverse ligament (f), of considerable importance and 
strength, connects the proximal ends of the metacarpals, a broad band or fork running 
upwards to the trapezium and binding down the tendon of the flexor carpi radialis. 
Fasciculi pass between the individual carpal bones and betwixt these and the ulna and 
radius, severally enclosing synovial sacs, partially intercommunicating, loose and easy- 
fitting. ‘The ligamentary union of the metacarpals and phalanges presents no feature 
of importance. 
Motions. From the flexibility of the wrist, carpus, and metacarpus, an unusually 
great freedom of motion ensues, partially restrained, however, by the powerful deep 
palmar fascia as above described. ‘The posterior ligament mainly influences the exterior 
margin of the manus, particularly lashing the fifth metacarpal, needful in the forward 
swing of the member. The anterior ligament similarly acts on this digit, but equally 
has a firm hold on the fourth, third, and second, so as to cause unison of movement in 
the acts of pronation, supination, and circumduction. The ulno-carpal plane being set 
almost crosswise to the last, causes the diagonal of force to run in a line swerving only 
slightly from the long diameter of the limb, while at the same time the double 
obliquity of the two ligaments enables a kind of hinge-movement to be performed as 
the radius and ulna twist upon themselves, which they do to a remarkable extent. 
The external lateral ligament has a kind of pulley-action as it swerves round the 
extremity of the radius. Laxity of the component parts of the whole joint is predomi- 
nant, a condition necessary to the varied movement the manus is capable of. 
3. Articulations of the Pelvis and Hind Limb. (Plate LX XIII.) 
Pelvic Articulations.—The pelvis is firmly and closely united with the sacrum by the 
sacro-iliac synchondrosis. 
Posteriorly a short but strong continuous ligament binds the ilium to the first and 
second sacral vertebre. ‘The fibres of this band (p.s.7, fig. 43) are placed obliquely for- 
wards and outwards, and pass from the transverse processes to the posterior inferior 
(superior in this case) spinous process of the ilium. 
The opposite moieties of the symphysis pubis are held loosely together by a thick 
and yery strong fibro-cartilage, which extends a short distance upon the brim of the 
pubis. 
There appears to be but one sacro-ischiatic ligament, which is more or less continuous 
with the deep pelvic fascia, and stretches from the ischium upwards and forwards to 
the side of the sacrum (s./). 
Between the transverse and spinous processes of several of the anterior caudal and 
last two sacral vertebre, there are strong ligamentous slips binding the one to the 
VOL. VII.—PART vil. January, 1872. 40 
