392: MR. ST. G. MIVART ON THE ANATOMY OF ECHIDNA HYSTRIX. 
On the other hand, it is inserted just external to a muscle which I take to be the 
pyriformis; and this is (in Man) the insertion of the gluteus medius. 
Gluteus minimus (and scansorius ?) (Plate LIII. fig. 2, G.m1).—This is a very large 
though somewhat thin expanse of muscle. It arises, by aponeurosis, from the spines of 
the anterior sacral and last lumbar vertebræ, and by muscular fibre from the whole outer 
surface and anterior border of the ilium; also, by a very strong tendon, from that part 
of the ilium which answers to the anterior superior spinous process of Man. Itis 
inserted, by strong tendinous fibres, into the upper end and whole anterior margin of the 
very elongated great trochanter. 
If the muscle which I have called g. medius be only a deeper portion of the g. mas- 
imus, then this large sheet of muscle which I have named g. minimus may really be the 
g. minimus and g. medius united, unless, indeed, it represent the g. medius only; for 
there is a very small but distinet bundle of muscular fibres which arises from the ilium, 
just external to the tendon of origin of the rectus, and which is inserted into the great 
trochanter just within, and a little above, the middle of the insertion of what I have 
called g. minimus. 
This little muscle may possibly be the true g. minimus ! ; and its insertion within and in 
front of what would then be the g. medius would harmonize with such a determination. 
. In the Ornithorhynchus? there are three large muscles very similar to those I have 
called gluteus maximus, g. medius, and g. minimus, and which Meckel has also so named. 
Pyriformis (Plate LIII. fig. 2, Py).—There is a muscle which arises from the transverse 
processes of about five caudal vertebrz a little anterior to a point opposite the tuberosity 
of the ischium. It is inserted into the femur immediately above and slightly behind the 
insertion of the muscle I have called gluteus medius. Iam disposed to consider ` „ui is 
the pyriformis, although the great sciatic nerve passes out superficially to it, instead of 
the muscle being superficial to the nerve. 
I could not find any trace of either a gemellus superior or inferior ; neither was there 
any muscle in the place of the obturator internus, the muscular fibres situated imme 
diately within the obturator foramen being those of the pubo-coccygeus. 
_ The obturator externus arises from the external circumference of the obturator fora- 
men, and is inserted, by a strong tendon, into the very shallow depression behind the 
great troehanter, just within, and more or less connected with, the lowest part of the 
insertion of the quadratus femoris. 
Quadratus femoris.—This delicate muscle arises from the tuberosity of the ischium 
and from the whole inferior margin of the ischium, from the tuberosity to the acetabulum: 
It is inserted into the posterior margin of the great trochanter, almost from its upper 
extremity as far down as the insertion of the obturator externus, with the tendon of whic 
it is more or less connected. 
Tibialis anticus.—There are two muscles together representing the tibialis anticus. 
The more internal of these (Plate LIII. figs. 1, 2 & 3, T.A 1), i. e. the muscle on the 
extreme tibial side of the front of the leg, arises from the upper half of the inner surface 
of the tibia, anterior to the internal lateral ligament. About the middle of the leg it 8! sa 
| The y. minimus is often very small, e. 9. in Nycticebus, Proc. Zool. Soc. 1865, p. 249; and in Cheiromy’ p 
Zool. Soc. vol. v. p. 66. * Meckel, loc. cit. p. 28, and tab. v. 24, 25, & 26. 
