208 OSTEOLOGY. 
bone becomes thick and rounded, and forms a wide notch which sweeps forwards 
and downwards to join the mass of bone behind the acetabulum, where it( become 
fused with the ischium ; this 1s-called the ilio-sciatic or great sciatic notch incisuras 
ischiadica major). 
The ium has two surfaces, an inner and an outer. The external surface is 
divided into two parts, viz. a lower acetabular, and an upper gluteal part. The 
CREST OF THR ILIUM 
Obliquus externus 
Obliquus internus 
Transversalis 
MIDDLE GLUTEAL LINE abdominis 
Gluteus medius 
oy 
Latissimus dorsi 
Gluteus 
minimus 
POSTERIOR 
GLUTEAL LINE \ 
4 Tensor 
fascie 
femoris 
ANTERIOR 
Gluteus 
SUPERIOR SPINE 
waximus —f 
Sartorius 
INFERIOR GLUTEAL 
POSTERIOR LINE 
SUPERIOR~ 
SPINE ] 
@ ANTERIOR INFERIOR 
SPINE 
/ ff 
= Great 7 Rectus femoris 
POSTERIOR INFERIOR SPINE SCTATIC fi 
atheae 8 NOTCH f : : ; 
Pyriformis —~Recetus femoris 
CorvLom NoTcH (reflected head) 
Groove for tendon of obturator = 
externus 
ACETABULUM 
BI L10-PECTINEAL EMINENCE 
ISCHIAL SPINE Pectineus 
SUPERIOR RAMU 
OF PUBIS 
_PUBIC SPINE 
Gemelli —- 
SMALL SCIATIC NOTCH 
Rectus abdowin 
.-_CREST OF PUBIS 
Pyramidalis 
— BoDY OF PUBIS 
Semimembranosus 
Biceps and semitendinosus 
~Adductor 
~ longus 
Pa Adductor brevis 
-A& ~—Gracilis 
fas 
ISCHIAL TUBEROSITY 
Quadratus femoris ~ 
magnus 
Obturator 
externus 
INFERIOR 
Adductor 
Ramus oF ISCHIUM 
Fic. 155.—TuHE Ricut INNOMINATE BONE AS SEEN FROM THE OUTER SIDE. 
lower forms a little less than the upper two-fifths of the acetabular hollow, and is 
separated from the larger gluteal surface above by the upper prominent margin of 
the articular cavity. The gluteal surface, broad and expanded, is concavo-convex 
from behind forward. It is traversed by three rough curved lines, well seen in 
strongly developed bones, but often faint and indistinct in feebly marked speci- 
mens. Of these the inferior curved line (linea eluteea inferior) curves backwards 
from a point immediately above the anterior inferior spine towards the ilio-sciatic 
notch posteriorly ; the bone between this and the acetabular margin is marked by 
