1896.] ANATOMY OF PETROGALE XANTHOPUS. 697 
The Triceps is large and has the human attachments. 
The Anconeus and Epitrochleo-anconeus are well marked and 
normal. 
The Pronator radii teres has only the condylar head, which is 
inserted just above the middle of the radius. 
The Flexor carpi radialis is normal. 
The Palmaris longus is large and ends in the palmar fascia, 
from the inner side of which a muscle rises, ending in tendons for 
the proximal and distal phalanges of the little finger; this I regard 
as the abductor minimi digiti. 
The Fle«or carpi ulnaris rises from the internal condyle and 
from the posterior border of the ulna; but there is no distinct 
head from the olecranon; the absence of this is also noticed by 
Macalister in the Great Kangaroo and Bennett’s Wallaby. The 
tendon is inserted into the pisiform bone, over which a sesamoid 
cartilage is situated. 
The Flexor sublimis digitorum is small, and rises from the 
surface of the flexor profundus; it quickly divides into three 
small muscular bellies, the tendons of which pass to the index, 
medius, and annularis. The descriptions of Meckel and Macalister 
agree with this, except that they found tendons to all the fingers. 
The Flevor profundus digitorum rises from the internal condyle, 
from the flexor surfaces of the radius and ulna in their upper 
halves, from the inner side of the ulna, and from the olecranon 
process. The mass divides intu five strong tendons for the thumb 
and fingers. 
The Lumbricales are arrauged as in Man, except that the one 
between the annularis and minimus tendons is wanting. This 
description differs from the one given by Young’. He describes 
four lumbricales in Petrogale, one of which is furnished to the 
thumb. 
The Pronator quadratus is very thick, and occupies the lower 
two-thirds of the forearm. 
The Supinator longus is inserted into the dorsum of the seaphoid. 
Macalister describes it as being inserted into the first metacarpal 
in the Wallaby, and into the trapezium and first metacarpal in the 
Great Kangaroo. Meckel also states that it is present in the 
Kangaroo. 
The Extensores carpi radialis longior et brevior were present and 
normal. Macalister says that they form a single muscle, which 
is inserted into the 2nd and 23rd metacarpals. I bave so often 
seen this description of these muscles by different authors in 
various animals, and, on trying to verify it, have always found the 
two muscles separate, though closely adherent, that I cannot help 
suspecting that they are normally separate in the Kangaroos. 
The Extensor communis digitorum is normal, and goes to the 
four outer fingers. ’ 
A soni Muscles of the Mammalian Hand,” Journ. Anat. vol. xiv. 
p. 156. 
Proc. Zoou. Soc.—1896, No. XLV. 45 
