544 DR. J. MURIE ON THE ANATOMY OF THE SEA-LION. 
d. Arteries of the Pelvic Limb. 
The distribution of these in most respects resembles what obtains in Phoca, slightly 
modified to correspond with the altered relations of the fleshy parts, agreeing therefore 
more closely with Zrichechus, where also caudo-calcaneal bands knit the heel well to- 
wards the spinal termination. The continuation of the abdominal aorta upon the in- 
ferior aspect of the tail, arteria sacra media, is noteworthy chiefly on account of a plexus 
vasculosus coccygeus or so-called coccygeal gland. This structure is represented in the 
Otary by an elongated somewhat cylindrical, yellowish, glandular-looking body, almost 
an inch long and 0:2 broad. It is situate between the converging long median tendons 
of the pubo- and ilio-coccygeal muscles, and is covered in part by the junctional raphé 
of the levator ani. 
External iliac and tributaries.—The epigastric is a large artery, which underlying 
the external and internal oblique muscles upon the surface of the transversalis and out- 
side the rectus, traverses the abdominal parietes and forms a free inosculation with the 
equally capacious internal mammary. 
The femoral artery, of very moderate calibre, on leaving the ilium, crosses out- 
wards almost at a right angle from it, and in this way traverses the groin to the 
inner and here posterior edge of the femur. The artery, with its companion vein and 
nerves, have the following relations before penetrating the adductor magnus muscle. 
The psoas tendon is superficial to it; the rectus femoris and sartorius lie anteriorly, 
the pectineus behind. These altogether form an elongated triangular space, the artery 
crossing this diagonally from before backwards. Deeply the vessel lies on the tendon 
of the iliacus, and then passes over the the adductor longus. At the lower third of 
the shaft of the femur it goes through a small opening in the upper border of the 
adductor magnus and reaches the posterior surface of the bone. 
The popliteal artery is very short, and, as usual, lies in the popliteal space; but its 
relations nevertheless are different, as the hamstring muscles are shifted downwards and 
do not approach the knee-joint, while the gastrocnemius has but one inner broad 
head of origin. On the inner side, then, it is enclosed superficially by the adductor 
magnus, and deeply by the gastrocnemius, these two muscles stretching from the con- 
dyloid ridge of the femur to the head of the tibia. On the outer side is the remarkably 
low insertion of the obturator externus, the upper portion of the biceps femoris, and 
the soleus. Having reached the inner side of the head of the fibula, the popliteal di- 
vides into anterior and posterior tibial arteries. 
This last-mentioned vessel rests on the popliteus and tibialis posticus, the long hallu- 
cial and digital flexor muscles in part covering it to the turn of the heel. The internal 
plantar artery appears to be that which furnishes the digital branchlets, or what here 
represents the plantar arch. It results that the distribution of the plantar is uncom- 
monly like that of the palmar vessels. The innermost artery runs alongside the hallux 
