1865. ] ANATOMY OF NYCTICEBUS. 249 
of an inch distant from it, as far as the first rib, into which it is in- 
serted. 
Muscles of the lower Extremity.—The gluteus minimus, the 
entogluteus of Owen’, is a very small fan-shaped muscle, arising 
from the junction of the iliumn and ischium, behind the acetabulum, 
and is inserted into the trochanter. 
This appears to be the muscle described by W. S. Church? as the 
gemellus superior ; but in our Nycticebus there is a distinct gemellus 
superior between the gluteus minimus and the tendon of the obtura- 
tor internus. 
The pyriformis is very largely developed. It arises from the 
anterior (abdominal) surface of the sacrum, and is inserted into the 
great trochanter. The sciatic nerve passes out beneath its inferior 
border. 
The authors of the joint memoir, though they mention by name, 
give no description of this muscle ; neither does Professor Owen in 
his monograph so often quoted. Meckel also says nothing of its 
existence in Loris, Burmeister® gives a long description of appa- 
rently the same muscle in Tarsius, and remarks that it must have a 
powerful action in rotating the thigh outwards. 
The gracilis has indeed a very extensive origin ; but it nevertheless 
is quite single, and shows no trace of the division described by Mec- 
kel’ as existing in Loris. It is inserted by a distinct but short 
tendon into the inner border of the tibia, beneath the sartorius. 
The *pectineus arises from the anterior surface of the pubis, and 
is inserted into the inner side of the femur. Professor Vrolik, in his 
article on the Quadrumana’, denies the existence of a pectineus in 
Stenops ; but Meckel asserts that in Loris it is very strong. 
The biceps femoris arises by a long and narrow tendon from the 
posterior end of the tuberosity of the ischium, beneath the semiten- 
dinosus. The fibres expand distally in a fan-like manner, and are 
inserted by an aponeurosis into the head of the fibula and the fascia 
of the leg. 
The semimembranosus arises from the ischium at its junction 
with the pubis, immediately beneath the origin of the semitendinosus, 
with which it is very closely connected. Passing downwards, it ends 
in a long tendon, which goes beneath the internal lateral ligament of 
the knee-joint, and is inserted into the inner side of the tuberosity of 
the tibia. 
The description of this muscle in Loris, as given in the French 
translation of Meckel, is too ambiguously worded for us to be able to 
decide whether it agrees with our observation. 
The tibialis anticus is a very large and powerful muscle, and 
arises from fully the upper half of the anterior surface of the tibia, 
and has its usual insertion (figs. 5 & 6, T.a). There is no trace 
' Cheiromys, p. 66. 
? Nat. Hist. Review, Jan. 1862, p. 87. 
° Op. cit. p. 69, t. 3. fig. 4, and t. 4. fig. 5, no. 7. 
* Loe. cit. p. 397. 
* Cyelop. Anat. and Physiol. vol. iv. p. 218. 
