18 MESSRS. F. E. BEDDARD AND F. TREVES ON THE (Jan. 15, 
Hyrax possesses in addition an extensor carpi ulnaris, which is 
wanting in the Ungulates. 
In Hyrax the extensores primi, secundi internodii, and indicis are 
wanting, which is so far a resemblance to the Ungulate in that the 
last two of these muscles are present im the Rabbit * and apparently 
in Hydromys. 
The supinator longus, which we have described in the Rhinoceros, 
is absent in the Horse, and according to Meckel, quoted by Messrs. 
Murie and Mivart,in many Rodents. Windle’ asserts its absence in 
Hydromys, and Huxley in the Rabbit. Its presence in Hyraz is 
therefore of particular mterest and also its presence in the Tapir. 
Muscles of the Hind Limbs (figs. 6, 7, 8, 9). 
Hiacus.—This muscle is largely tendinous upon the inner side ; 
its origin is from the whole of the iliac fossa. 
Psoas.—A small muscle dividing into two tendons; both are 
mserted into lesser trochanter, curving round femur from before 
back. 
Psoas parvus.—The upper part of the belly is museular but 
soon becomes tendinous; it is continuous with the sartorius (see 
fig. 7). 
Gracilis.—The gracilis is enormously wide and muscular through- 
out ; it arises from pubic arch and is inserted by a large muscular 
and tendinous insertion into fascia above the imner side of the knee, 
which is continued on to patella and then on to inner side of tibia. 
Pectineus is a fleshy, somewhat flat oblong-shaped muscle; it 
arises from pubis along pectineal line ; it is inserted on to the femur 
as in the Horse. 
Adductor longus.—Arises from ramus of pubis, where it is blended 
with adductor magnus; its insertion is the same as that of the 
gracilis, except that it also is attached to the lower end of the femur ; 
it is partly covered by gracilis. 
Adductor magnus is a large fleshy muscle with but little tendon ; 
its origin is muscular and it is here fused with adductor longus as 
already stated ; its insertion is to inner side of shaft and to inner 
condyle of femur ; it forms a tendinous arch for artery at junction 
of middle and lower third. 
The Rectus and two Vasti were fused into a single muscle, the 
elements of which were indicated by aponeuroses ; the muscle is 
inserted on to patella. 
Semimembranosus.—This muscle is united to form one muscle 
with the semitendinosus ; it is inserted by a flat tendon parallel with 
and + inch behind the erest of tibia; this tendon is three inches 
Jong. 
The Peronei muscles are four in number :— 
(1) Originates from the outer side of the head of the fibula and 
© Huxley, ‘Anatomy of Vertebrates,’ p. 489. 
P. Z. 8. 1887, p. 56. 
