1882.] DR. GADOW ON THE ANATOMY OF PTEROCLES. 315 
muscles of the shoulder-girdle I am indebted to Prof. Fuerbringer for 
the information that Pterocles approaches nearer to the Pigeons than 
to the Fowls. 
Mn. iliaci externi (mm. glutei).—This group in Pterocles con- 
sists of only two muscles, an anterior and a posterior. Of these the 
latter is the larger; it arises from the broad latero-dorsal plane of 
the praeacetabular part of the ilium, andis inserted close to the external 
trochanter of the femur. The iliac muscles have their nerve-supply 
from the crural plexus. 
M. iliacus internus.—This small muscle is comparatively long, as 
it arises from nearly the middle of the ventral aspect of the preeace- 
tabular ilium. It is inserted as usual, between the internal trochanter 
and the neck of the femur. 
M. sartorius—Flat and very broad, from the greater part of the 
lateral and dorsal margin of the preeacetabular ilium. The muscle is 
partly blended with the m. ilio-tidialis at the distal third of the 
thigh ; the rest passes over the patella as a flat but nevertheless 
rather fleshy strip, and then extends into part of the head of the 
m. extensor digitorum communis. The muscle is supplied by nerves 
from one of the first branches of the crural plexus. 
M. ilio-tibialis (m. quadratus femoris) —This muscle is rather 
feebly developed ; it arises with an aponeurotic sheet, which super- 
ficially covers the mm. iliaci externi, and which also takes origin 
from the regio posttrochanterica of the ilium. ‘The muscle is com- 
pletely blended with the m. femoro-tibialis, with the m. gluteus 
posterior, and with the m. sartorius. It is inserted together with 
the tendon of the mesial and external part of the m. femoro-tibialis 
into the head and rest of the tibia. Nerve-supply from the crural 
plexus. 
The m. gluteus posterior + m. tensor fascie late (m. tensor 
fascize latee) arises rather fleshy from the lateral plane of the postace- 
tabular part of the ilium, and is inserted indirectly into the head of 
the tibia by being attached to the distal’part of the m. ilio-tibialis. 
Nerve from the ischiadic plexus. 
The m. gluteus anterior (m. gluteus quartus) is very small; its 
muscular part consists of only a few fibres. Its aponeurosis arises 
from the space left between the origin of the m. iliac. ext. post. and 
the antitrochanter. Its short but broad and flat tendon runs over the 
external trochanter, passes the tendons of the external iliac muscles, 
and is inserted just distad from their insertion into the outer aspect 
of the femur. The nerve to this muscle is given off from the pl. 
ischiadicus ; it passes round behind the antitrochanter out of the 
ischiadic foramen. 
The m. ambiens arises with a short and distinct tendon from the 
pubic spine ; its roundish and somewhat ribbon-shaped belly tapers 
out into a long slender tendon, which, after partly piercing that of 
the m. femoro-tibialis, passes over the knee into its outer side and 
then supports one of the heads of the m. flexor perforatus digiti 11. 
Between the proximal part of the ambiens muscle and the inner 
trochanter of the femur, that long nervous branch which is sent off 
