588 DR. J. MURIE ON THE ANATOMY OF THE SEA-LION. 
and runs almost parallel with it. Its attachments are:—posteriorly, the front and 
deep surface of the caleaneum; anteriorly, the hinder surface and inner side of the 
cuboid bone. 
Scapho-cuboid ligaments—TLwo in number, an internal dorsal (fig. 40, s.cb') and a 
narrower plantar one. These simply connect the said bones in the manner of a hinge- 
joint; but the two short deep plantar muscles already spoken of, lying on the peroneal 
side of the plantar ligament, also flex the cuboid upon the scaphoid. 
Deep Plantar Fascia.—Covering or superficial to those ligaments on the sole of the 
foot above described, is a thick, uncommonly stout layer of plantar fascia (D.p.f, fig. 38). 
It reaches from the heel forwards to opposite the proximal ends of the metatarsals, and 
there, binding down the tendon of the peroneus longus, fastens itself partly to the bones 
and deep interossei, and a portion is continuous with the semilunar musculo-tendinous 
sheet of the superficial interosseous layer. 
Use. This fascia, whilst admitting of some amount of yielding by the posterior seg- 
ment of the sole, also performs the office of a rigid plane to the foot, similar to what is 
supplied by the deep palmar fascia. There is this difference, however—that its extension 
forwards to the great toe is less marked than what obtains in the pollex. Hence there 
is less firmness in the foot’s step, especially comparative diminution in rigidity of the 
two inner toes; and as the interdigital membrane also is looser, the entire pes is far 
more flexible than is the manus. 
DESCRIPTION OF THE PLATES. 
PLATE LXVIL. 
Fig. 1. Upper surface, right fore extremity (manus). Reduced 3 from nature. The 
numerals correspond to the digits. 
Fig. 2. Dorsum of hind flipper (pes) with its digits expanded. 
Fig. 3, The same in its contracted condition. Both 3 nat. size. 
PLATE LXVIII. 
Fig. 4. Palmar aspect of the fore flipper. 3 nat. size. 
Fig. 5. Portion of hinder end of the body and the entire left posterior limb seen ven- 
trally: P, penis, protruding from sheath; s, scrotum, partly hiding 4, the 
anus; 7’, tail. 
Fig. 6. Reduced sketch of the scrotal sac (s) as it bulges when the two limbs are closely 
approximated. 
