700 MR. F. G. PARSONS ON THE [June 16, 
The Flevor caude internus is inserted by long tendons into the 
ventral surface of the roots of the transverse processes, the most 
internal tendons being first inserted, while the deeper ones reach 
the surface round the outer side of them. 
The Flexor caude profundus is fleshy, and runs along the 
ventral surface of the tail close to the middle line, being concealed 
by the last muscle and separated by a nerve from the flexor 
caude externus. 
Muscles of the Posterior Extremity. 
The Gluteus maximus or Ectogluteus is a small thin sheet of 
muscle rising from the sacral spines and fusing anteriorly with 
the sacro-lumbalis. It is inserted just below the great trochanter. 
The Gluteus medius is much larger than the last, and rises from 
the greater part of the gluteal surface of the ilium by two per- 
fectly distinct layers, of which the superficial is inserted by flesh 
and the deep by tendon into the outer side of the great trochanter. 
The Gluteus minimus is small, and is covered by the medius ; 
it is inserted by tendon into the front of the great trochanter. 
The Gluteus quartus or Scansorius is very distinct and comes 
from the ventral border of the ilium; it is inserted into the 
anterior surface of the femur just below the great trochanter. 
The Z'ensor fascie femoris and Sartorius are inseparable, the 
latter part being feebly marked; they rise from the anterior 
ventral spine of the ilium and are inserted into the fascia of the 
thigh rearly as far as the patella. This sheet of muscle is 
supplied entirely by the anterior crural nerve. 
The Pyriformis is well marked and normal. 
The Obturator internus is normal ; on its deep surface the tendon 
is divided into three bands. 
The Gemelli are represented by one continuous muscle, which 
rises from the ventral margin of the lesser sciatic notch ; it is best 
seen when the obturator internus is cut and reflected. Meckel! 
states that these muscles are absent in the Kangaroo. 
The Quadratus femoris is a large triangular muscle, which is 
inserted by tendon into the second quarter of the femur. 
The Obturator exvternus is large and normal. 
The Biceps consists of two parts, though I am doubtful whether 
the part described first should not rather be included with the 
gluteus maximus. The anterior portion rises from the posterior 
sacral and anterior caudal] spines and transverse processes ; it is 
inserted by a narrow tendon into the outer side of the patella. 
The posterior part is large and rises from the ischial tuberosity as 
well as by a small origin from the caudal vertebrez ; it is inserted 
into the fascia of the upper half of the leg. 
The Semitendinosus rises from the tuber ischii with the biceps, 
and is inserted into the cnemial crest of the tibia. 
The Semimembranosus is a small muscle ; it rises from the tuber 
1 « Anatomie comparée,’ vol. vi. p. 364. 
