PELVIC LIMBS 675 



itself. Above the rim of the acetabulum is a narrow area of origin 

 of the rectus femoris muscle. 



The inner surface of the ilium (Fig. 522) above and in front of 

 the ilio-pectineal line is concave, and forms the iliac fossa for the iliac 

 muscle ; behind the line and above the greater sacro-sciatic notch is the 

 auricular surface for the sacrum, surmounted by the rough tuberosity 

 for ligaments. Only a small portion of the ilium extends in front 

 of the notch and below the ilio-pectineal line to meet the ischium. 

 To this portion is attached part of the obturator interims muscle. On 

 the ilio-pectineal line is inserted the psoas parvus. 



The ischium is shaped like a horseshoe, and is shorter and thicker 

 than the ischium of the cat. It has a body and an ascending ramus. 

 Where the body joins the ilium on the inner surface is a variable 

 ilio-ischial line. The spine is sharp and triangular ; it is separated 

 from the swollen tuberosity by the lesser sacro-sciatic notch. To the 

 spine are fastened the gemellus superior, coccygeus, and levator ani 

 muscles ; the gemellus inferior arises below the spine ; and between the 

 two lips of the tuberosity are attached the semimembranosus, semi- 

 tendinosus, and biceps femoris muscles. 



Between the rim of the acetabulum and the tuberosity is the 

 obturator groove for the internal obturator muscle. To the outer 

 surface of the body of the ischium is fastened the quadratus femoris 

 muscle, and to the outer surface of both the body and the ramus, the 

 obturator externus and the adductor magnus. 



The obturator interims muscle arises from the inner surface of the 

 body and the ramus, and the transversus perinei from,. the ramus only. 



The pubes is relatively shorter than the pubes of the cat. It has 

 a body and horizontal and descending rami. 



The body is quadrilateral ; its upper surface, or crest, has a sharp 

 anterior margin which presents the pubic spine for the attachment of 

 Poupart's ligament, coming from the superior iliac spine. The internal 

 angle is the pubic angle, between which and the spine are attached the 

 rectus abdominis and pyramidalis muscles. 



The posterior surface of the body is smooth, and continuous down- 

 ward with the surface of the descending ramus and outward with the 

 surface of the horizontal ramus. It affords attachment to the levator 

 ani and obturator internus muscles ; the latter muscle is also attached 

 to the surfaces of the rami. 



